essay on urban pollution

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• Published: 29 October 2020

Urban and air pollution: a multi-city study of long-term effects of urban landscape patterns on air quality trends

• Lu Liang 1 &
• Peng Gong 2 , 3 , 4  

Scientific Reports volume  10 , Article number:  18618 ( 2020 ) Cite this article

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Most air pollution research has focused on assessing the urban landscape effects of pollutants in megacities, little is known about their associations in small- to mid-sized cities. Considering that the biggest urban growth is projected to occur in these smaller-scale cities, this empirical study identifies the key urban form determinants of decadal-long fine particulate matter (PM 2.5 ) trends in all 626 Chinese cities at the county level and above. As the first study of its kind, this study comprehensively examines the urban form effects on air quality in cities of different population sizes, at different development levels, and in different spatial-autocorrelation positions. Results demonstrate that the urban form evolution has long-term effects on PM 2.5 level, but the dominant factors shift over the urbanization stages: area metrics play a role in PM 2.5 trends of small-sized cities at the early urban development stage, whereas aggregation metrics determine such trends mostly in mid-sized cities. For large cities exhibiting a higher degree of urbanization, the spatial connectedness of urban patches is positively associated with long-term PM 2.5 level increases. We suggest that, depending on the city’s developmental stage, different aspects of the urban form should be emphasized to achieve long-term clean air goals.

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Introduction

Air pollution represents a prominent threat to global society by causing cascading effects on individuals 1 , medical systems 2 , ecosystem health 3 , and economies 4 in both developing and developed countries 5 , 6 , 7 , 8 . About 90% of global citizens lived in areas that exceed the safe level in the World Health Organization (WHO) air quality guidelines 9 . Among all types of ecosystems, urban produce roughly 78% of carbon emissions and substantial airborne pollutants that adversely affect over 50% of the world’s population living in them 5 , 10 . While air pollution affects all regions, there exhibits substantial regional variation in air pollution levels 11 . For instance, the annual mean concentration of fine particulate matter with an aerodynamic diameter of less than 2.5  \(\upmu\mathrm{m}\) (PM 2.5 ) in the most polluted cities is nearly 20 times higher than the cleanest city according to a survey of 499 global cities 12 . Many factors can influence the regional air quality, including emissions, meteorology, and physicochemical transformations. Another non-negligible driver is urbanization—a process that alters the size, structure, and growth of cities in response to the population explosion and further leads to lasting air quality challenges 13 , 14 , 15 .

With the global trend of urbanization 16 , the spatial composition, configuration, and density of urban land uses (refer to as urban form) will continue to evolve 13 . The investigation of urban form impacts on air quality has been emerging in both empirical 17 and theoretical 18 research. While the area and density of artificial surface areas have well documented positive relationship with air pollution 19 , 20 , 21 , the effects of urban fragmentation on air quality have been controversial. In theory, compact cities promote high residential density with mixed land uses and thus reduce auto dependence and increase the usage of public transit and walking 21 , 22 . The compact urban development has been proved effective in mitigating air pollution in some cities 23 , 24 . A survey of 83 global urban areas also found that those with highly contiguous built-up areas emitted less NO 2 22 . In contrast, dispersed urban form can decentralize industrial polluters, improve fuel efficiency with less traffic congestion, and alleviate street canyon effects 25 , 26 , 27 , 28 . Polycentric and dispersed cities support the decentralization of jobs that lead to less pollution emission than compact and monocentric cities 29 . The more open spaces in a dispersed city support air dilution 30 . In contrast, compact cities are typically associated with stronger urban heat island effects 31 , which influence the availability and the advection of primary and secondary pollutants 32 .

The mixed evidence demonstrates the complex interplay between urban form and air pollution, which further implies that the inconsistent relationship may exist in cities at different urbanization levels and over different periods 33 . Few studies have attempted to investigate the urban form–air pollution relationship with cross-sectional and time series data 34 , 35 , 36 , 37 . Most studies were conducted in one city or metropolitan region 38 , 39 or even at the country level 40 . Furthermore, large cities or metropolitan areas draw the most attention in relevant studies 5 , 41 , 42 , and the small- and mid-sized cities, especially those in developing countries, are heavily underemphasized. However, virtually all world population growth 43 , 44 and most global economic growth 45 , 46 are expected to occur in those cities over the next several decades. Thus, an overlooked yet essential task is to account for various levels of cities, ranging from large metropolitan areas to less extensive urban area, in the analysis.

This study aims to improve the understanding of how the urban form evolution explains the decadal-long changes of the annual mean PM 2.5 concentrations in 626 cities at the county-level and above in China. China has undergone unprecedented urbanization over the past few decades and manifested a high degree of heterogeneity in urban development 47 . Thus, Chinese cities serve as a good model for addressing the following questions: (1) whether the changes in urban landscape patterns affect trends in PM 2.5 levels? And (2) if so, do the determinants vary by cities?

City boundaries

Our study period spans from the year 2000 to 2014 to keep the data completeness among all data sources. After excluding cities with invalid or missing PM 2.5 or sociodemographic value, a total of 626 cities, with 278 prefecture-level cities and 348 county-level cities, were selected. City boundaries are primarily based on the Global Rural–Urban Mapping Project (GRUMP) urban extent polygons that were defined by the extent of the nighttime lights 48 , 49 . Few adjustments were made. First, in the GRUMP dataset, large agglomerations that include several cities were often described in one big polygon. We manually split those polygons into individual cities based on the China Administrative Regions GIS Data at 1:1 million scales 50 . Second, since the 1978 economic reforms, China has significantly restructured its urban administrative/spatial system. Noticeable changes are the abolishment of several prefectures and the promotion of many former county-level cities to prefecture-level cities 51 . Thus, all city names were cross-checked between the year 2000 and 2014, and the mismatched records were replaced with the latest names.

PM 2.5 concentration data

The annual mean PM 2.5 surface concentration (micrograms per cubic meter) for each city over the study period was calculated from the Global Annual PM 2.5 Grids at 0.01° resolution 52 . This data set combines Aerosol Optical Depth retrievals from multiple satellite instruments including the NASA Moderate Resolution Imaging Spectroradiometer (MODIS), Multi-angle Imaging SpectroRadiometer (MISR), and the Sea-Viewing Wide Field-of-View Sensor (SeaWiFS). The global 3-D chemical transport model GEOS-Chem is further applied to relate this total column measure of aerosol to near-surface PM 2.5 concentration, and geographically weighted regression is finally used with global ground-based measurements to predict and adjust for the residual PM 2.5 bias per grid cell in the initial satellite-derived values.

Human settlement layer

The urban forms were quantified with the 40-year (1978–2017) record of annual impervious surface maps for both rural and urban areas in China 47 , 53 . This state-of-art product provides substantial spatial–temporal details on China’s human settlement changes. The annual impervious surface maps covering our study period were generated from 30-m resolution Landsat images acquired onboard Landsat 5, 7, and 8 using an automatic “Exclusion/Inclusion” mapping framework 54 , 55 . The output used here was the binary impervious surface mask, with the value of one indicating the presence of human settlement and the value of zero identifying non-residential areas. The product assessment concluded good performance. The cross-comparison against 2356 city or town locations in GeoNames proved an overall high agreement (88%) and approximately 80% agreement was achieved when compared against visually interpreted 650 urban extent areas in the year 1990, 2000, and 2010.

Control variables

To provide a holistic assessment of the urban form effects, we included control variables that are regarded as important in influencing air quality to account for the confounding effects.

Four variables, separately population size, population density, and two economic measures, were acquired from the China City Statistical Yearbook 56 (National Bureau of Statistics 2000–2014). Population size is used to control for the absolute level of pollution emissions 41 . Larger populations are associated with increased vehicle usage and vehicle-kilometers travels, and consequently boost tailpipes emissions 5 . Population density is a useful reflector of transportation demand and the fraction of emissions inhaled by people 57 . We also included gross regional product (GRP) and the proportion of GRP generated from the secondary sector (GRP2). The impact of economic development on air quality is significant but in a dynamic way 58 . The rising per capita income due to the concentration of manufacturing industrial activities can deteriorate air quality and vice versa if the stronger economy is the outcome of the concentration of less polluting high-tech industries. Meteorological conditions also have short- and long-term effects on the occurrence, transport, and dispersion of air pollutants 59 , 60 , 61 . Temperature affects chemical reactions and atmospheric turbulence that determine the formation and diffusion of particles 62 . Low air humidity can lead to the accumulation of air pollutants due to it is conducive to the adhesion of atmospheric particulate matter on water vapor 63 . Whereas high humidity can lead to wet deposition processes that can remove air pollutants by rainfall. Wind speed is a crucial indicator of atmospheric activity by greatly affect air pollutant transport and dispersion. All meteorological variables were calculated based on China 1 km raster layers of monthly relative humidity, temperature, and wind speed that are interpolated from over 800 ground monitoring stations 64 . Based on the monthly layer, we calculated the annual mean of each variable for each year. Finally, all pixels falling inside of the city boundary were averaged to represent the overall meteorological condition of each city.

Considering the dynamic urban form-air pollution relationship evidenced from the literature review, our hypothesis is: the determinants of PM 2.5 level trends are not the same for cities undergoing different levels of development or in different geographic regions. To test this hypothesis, we first categorized city groups following (1) social-economic development level, (2) spatial autocorrelation relationship, and (3) population size. We then assessed the relationship between urban form and PM 2.5 level trends by city groups. Finally, we applied the panel data models to different city groups for hypothesis testing and key determinant identification (Fig.  1 ).

Methodology workflow.

Calculation of urban form metrics

Based on the previous knowledge 65 , 66 , 67 , fifteen landscape metrics falling into three categories, separately area, shape, and aggregation, were selected. Those metrics quantify the compositional and configurational characteristics of the urban landscape, as represented by urban expansion, urban shape complexity, and compactness (Table 1 ).

Area metrics gives an overview of the urban extent and the size of urban patches that are correlated with PM 2.5 20 . As an indicator of the urbanization degree, total area (TA) typically increases constantly or remains stable, because the urbanization process is irreversible. Number of patches (NP) refers to the number of discrete parcels of urban settlement within a given urban extent and Mean Patch Size (AREA_MN) measures the average patch size. Patch density (PD) indicates the urbanization stages. It usually increases with urban diffusion until coalescence starts, after which decreases in number 66 . Largest Patch Index (LPI) measures the percentage of the landscape encompassed by the largest urban patch.

The shape complexity of urban patches was represented by Mean Patch Shape Index (SHAPE_MN), Mean Patch Fractal Dimension (FRAC_MN), and Mean Contiguity Index (CONTIG_MN). The greater irregularity the landscape shape, the larger the value of SHAPE_MN and FRAC_MN. CONTIG_MN is another method of assessing patch shape based on the spatial connectedness or contiguity of cells within a patch. Larger contiguous patches will result in larger CONTIG_MN.

Aggregation metrics measure the spatial compactness of urban land, which affects pollutant diffusion and dilution. Mean Euclidean nearest-neighbor distance (ENN_MN) quantifies the average distance between two patches within a landscape. It decreases as patches grow together and increases as the urban areas expand. Landscape Shape Index (LSI) indicates the divergence of the shape of a landscape patch that increases as the landscape becomes increasingly disaggregated 68 . Patch Cohesion Index (COHESION) is suggestive of the connectedness degree of patches 69 . Splitting Index (SPLIT) and Landscape Division Index (DIVISION) increase as the separation of urban patches rises, whereas, Mesh Size (MESH) decreases as the landscape becomes more fragmented. Aggregation Index (AI) measures the degree of aggregation or clumping of urban patches. Higher values of continuity indicate higher building densities, which may have a stronger effect on pollution diffusion.

The detailed descriptions of these indices are given by the FRAGSTATS user’s guide 70 . The calculation input is a layer of binary grids of urban/nonurban. The resulting output is a table containing one row for each city and multiple columns representing the individual metrics.

Division of cities

Division based on the socioeconomic development level.

The socioeconomic development level in China is uneven. The unequal development of the transportation system, descending in topography from the west to the east, combined with variations in the availability of natural and human resources and industrial infrastructure, has produced significantly wide gaps in the regional economies of China. By taking both the economic development level and natural geography into account, China can be loosely classified into Eastern, Central, and Western regions. Eastern China is generally wealthier than the interior, resulting from closeness to coastlines and the Open-Door Policy favoring coastal regions. Western China is historically behind in economic development because of its high elevation and rugged topography, which creates barriers in the transportation infrastructure construction and scarcity of arable lands. Central China, echoing its name, is in the process of economic development. This region neither benefited from geographic convenience to the coast nor benefited from any preferential policies, such as the Western Development Campaign.

Division based on spatial autocorrelation relationship

The second type of division follows the fact that adjacent cities are likely to form air pollution clusters due to the mixing and diluting nature of air pollutants 71 , i.e., cities share similar pollution levels as its neighbors. The underlying processes driving the formation of pollution hot spots and cold spots may differ. Thus, we further divided the city into groups based on the spatial clusters of PM 2.5 level changes.

Local indicators of spatial autocorrelation (LISA) was used to determine the local patterns of PM 2.5 distribution by clustering cities with a significant association. In the presence of global spatial autocorrelation, LISA indicates whether a variable exhibits significant spatial dependence and heterogeneity at a given scale 72 . Practically, LISA relates each observation to its neighbors and assigns a value of significance level and degree of spatial autocorrelation, which is calculated by the similarity in variable \(z\) between observation \(i\) and observation \(j\) in the neighborhood of \(i\) defined by a matrix of weights \({w}_{ij}\) 7 , 73 :

where \({I}_{i}\) is the Moran’s I value for location \(i\) ; \({\sigma }^{2}\) is the variance of variable \(z\) ; \(\bar{z}\) is the average value of \(z\) with the sample number of \(n\) . The weight matrix \({w}_{ij}\) is defined by the k-nearest neighbors distance measure, i.e., each object’s neighborhood consists of four closest cites.

The computation of Moran’s I enables the identification of hot spots and cold spots. The hot spots are high-high clusters where the increase in the PM 2.5 level is higher than the surrounding areas, whereas cold spots are low-low clusters with the presence of low values in a low-value neighborhood. A Moran scatterplot, with x-axis as the original variable and y-axis as the spatially lagged variable, reflects the spatial association pattern. The slope of the linear fit to the scatter plot is an estimation of the global Moran's I 72 (Fig.  2 ). The plot consists of four quadrants, each defining the relationship between an observation 74 . The upper right quadrant indicates hot spots and the lower left quadrant displays cold spots 75 .

Moran’s I scatterplot. Figure was produced by R 3.4.3 76 .

Division based on population size

The last division was based on population size, which is a proven factor in changing per capita emissions in a wide selection of global cities, even outperformed land urbanization rate 77 , 78 , 79 . We used the 2014 urban population to classify the cities into four groups based on United Nations definitions 80 : (1) large agglomerations with a total population larger than 1 million; (2) mid-sized cities, 500,000–1 million; (3) small cities, 250,000–500,000, and (4) very small cities, 100,000–250,000.

Panel data analysis

The panel data analysis is an analytical method that deals with observations from multiple entities over multiple periods. Its capacity in analyzing the characteristics and changes from both the time-series and cross-section dimensions of data surpasses conventional models that purely focus on one dimension 81 , 82 . The estimation equation for the panel data model in this study is given as:

where the subscript \(i\) and \(t\) refer to city and year respectively. \(\upbeta _{{0}}\) is the intercept parameter and \(\upbeta _{{1}} - { }\upbeta _{{{18}}}\) are the estimates of slope coefficients. \(\varepsilon \) is the random error. All variables are transformed into natural logarithms.

Two methods can be used to obtain model estimates, separately fixed effects estimator and random effects estimator. The fixed effects estimator assumes that each subject has its specific characteristics due to inherent individual characteristic effects in the error term, thereby allowing differences to be intercepted between subjects. The random effects estimator assumes that the individual characteristic effect changes stochastically, and the differences in subjects are not fixed in time and are independent between subjects. To choose the right estimator, we run both models for each group of cities based on the Hausman specification test 83 . The null hypothesis is that random effects model yields consistent and efficient estimates 84 : \({H}_{0}{:}\,E\left({\varepsilon }_{i}|{X}_{it}\right)=0\) . If the null hypothesis is rejected, the fixed effects model will be selected for further inferences. Once the better estimator was determined for each model, one optimal panel data model was fit to each city group of one division type. In total, six, four, and eight runs were conducted for socioeconomic, spatial autocorrelation, and population division separately and three, two, and four panel data models were finally selected.

Spatial patterns of PM 2.5 level changes

During the period from 2000 to 2014, the annual mean PM 2.5 concentration of all cities increases from 27.78 to 42.34 µg/m 3 , both of which exceed the World Health Organization recommended annual mean standard (10 µg/m 3 ). It is worth noting that the PM 2.5 level in the year 2014 also exceeds China’s air quality Class 2 standard (35 µg/m 3 ) that applies to non-national park places, including urban and industrial areas. The standard deviation of annual mean PM 2.5 values for all cities increases from 12.34 to 16.71 µg/m 3 , which shows a higher variability of inter-urban PM 2.5 pollution after a decadal period. The least and most heavily polluted cities in China are Delingha, Qinghai (3.01 µg/m 3 ) and Jizhou, Hubei (64.15 µg/m 3 ) in 2000 and Hami, Xinjiang (6.86 µg/m 3 ) and Baoding, Hubei (86.72 µg/m 3 ) in 2014.

Spatially, the changes in PM 2.5 levels exhibit heterogeneous patterns across cities (Fig.  3 b). According to the socioeconomic level division (Fig.  3 a), the Eastern, Central, and Western region experienced a 38.6, 35.3, and 25.5 µg/m 3 increase in annual PM 2.5 mean , separately, and the difference among regions is significant according to the analysis of variance (ANOVA) results (Fig.  4 a). When stratified by spatial autocorrelation relationship (Fig.  3 c), the differences in PM 2.5 changes among the spatial clusters are even more dramatic. The average PM 2.5 increase in cities belonging to the high-high cluster is approximately 25 µg/m 3 , as compared to 5 µg/m 3 in the low-low clusters (Fig.  4 b). Finally, cities at four different population levels have significant differences in the changes of PM 2.5 concentration (Fig.  3 d), except for the mid-sized cities and large city agglomeration (Fig.  4 c).

( a ) Division of cities in China by socioeconomic development level and the locations of provincial capitals; ( b ) Changes in annual mean PM 2.5 concentrations between the year 2000 and 2014; ( c ) LISA cluster maps for PM 2.5 changes at the city level; High-high indicates a statistically significant cluster of high PM 2.5 level changes over the study period. Low-low indicates a cluster of low PM 2.5 inter-annual variation; No high-low cluster is reported; Low–high represents cities with high PM 2.5 inter-annual variation surrounded by cities with low variation; ( d ) Population level by cities in the year 2014. Maps were produced by ArcGIS 10.7.1 85 .

Boxplots of PM 2.5 concentration changes between 2000 and 2014 for city groups that are formed according to ( a ) socioeconomic development level division, ( b ) LISA clusters, and ( c ) population level. Asterisk marks represent the p value of ANOVA significant test between the corresponding pair of groups. Note ns not significant; * p value < 0.05; ** p value < 0.01; *** p value < 0.001; H–H high-high cluster, L–H low–high cluster, L–L denotes low–low cluster.

The effects of urban forms on PM 2.5 changes

The Hausman specification test for fixed versus random effects yields a p value less than 0.05, suggesting that the fixed effects model has better performance. We fit one panel data model to each city group and built nine models in total. All models are statistically significant at the p  < 0.05 level and have moderate to high predictive power with the R 2 values ranging from 0.63 to 0.95, which implies that 63–95% of the variation in the PM 2.5 concentration changes can be explained by the explanatory variables (Table 2 ).

The urban form—PM 2.5 relationships differ distinctly in Eastern, Central, and Western China. All models reach high R 2 values. Model for Eastern China (refer to hereafter as Eastern model) achieves the highest R 2 (0.90), and the model for the Western China (refer to hereafter as Western model) reaches the lowest R 2 (0.83). The shape metrics FRAC and CONTIG are correlated with PM 2.5 changes in the Eastern model, whereas the area metrics AREA demonstrates a positive effect in the Western model. In contrast to the significant associations between shape, area metrics and PM 2.5 level changes in both Eastern and Western models, no such association was detected in the Central model. Nonetheless, two aggregation metrics, LSI and AI, play positive roles in determining the PM 2.5 trends in the Central model.

For models built upon the LISA clusters, the H–H model (R 2  = 0.95) reaches a higher fitting degree than the L–L model (R 2  = 0.63). The estimated coefficients vary substantially. In the H–H model, the coefficient of CONTIG is positive, which indicates that an increase in CONTIG would increase PM 2.5 pollution. In contrast, no shape metrics but one area metrics AREA is significant in the L–L model.

The results of the regression models built for cities at different population levels exhibit a distinct pattern. No urban form metrics was identified to have a significant relationship with the PM 2.5 level changes in groups of very small and mid-sized cities. For small size cities, the aggregation metrics COHESION was positively associated whereas AI was negatively related. For mid-sized cities and large agglomerations, CONTIG is the only significant variable that is positively related to PM 2.5 level changes.

Urban form is an effective measure of long-term PM 2.5 trends

All panel data models are statistically significant regardless of the data group they are built on, suggesting that the associations between urban form and ambient PM 2.5 level changes are discernible at all city levels. Importantly, these relationships are found to hold when controlling for population size and gross domestic product, implying that the urban landscape patterns have effects on long-term PM 2.5 trends that are independent of regional economic performance. These findings echo with the local, regional, and global evidence of urban form effect on various air pollution types 5 , 14 , 21 , 22 , 24 , 39 , 78 .

Although all models demonstrate moderate to high predictive power, the way how different urban form metrics respond to the dependent variable varies. Of all the metrics tested, shape metrics, especially CONTIG has the strongest effect on PM 2.5 trends in cities belonging to the high-high cluster, Eastern, and large urban agglomerations. All those regions have a strong economy and higher population density 86 . In the group of cities that are moderately developed, such as the Central region, as well as small- and mid-sized cities, aggregation metrics play a dominant negative role in PM 2.5 level changes. In contrast, in the least developed cities belonging to the low-low cluster regions and Western China, the metrics describing size and number of urban patches are the strongest predictors. AREA and NP are positively related whereas TA is negatively associated.

The impacts of urban form metrics on air quality vary by urbanization degree

Based on the above observations, how urban form affects within-city PM 2.5 level changes may differ over the urbanization stages. We conceptually summarized the pattern in Fig.  5 : area metrics have the most substantial influence on air pollution changes at the early urban development stage, and aggregation metrics emerge at the transition stage, whereas shape metrics affect the air quality trends at the terminal stage. The relationship between urban form and air pollution has rarely been explored with such a wide range of city selections. Most prior studies were focused on large urban agglomeration areas, and thus their conclusions are not representative towards small cities at the early or transition stage of urbanization.

The most influential metric of urban form in affecting PM 2.5 level changes at different urbanization stages.

Not surprisingly, the area metrics, which describe spatial grain of the landscape, exert a significant effect on PM 2.5 level changes in small-sized cities. This could be explained by the unusual urbanization speed of small-sized cities in the Chinese context. Their thriving mostly benefited from the urbanization policy in the 1980s, which emphasized industrialization of rural, small- and mid-sized cities 87 . With the large rural-to-urban migration and growing public interest in investing real estate market, a side effect is that the massive housing construction that sometimes exceeds market demand. Residential activities decline in newly built areas of smaller cities in China, leading to what are known as ghost cities 88 . Although ghost cities do not exist for all cities, high rate of unoccupied dwellings is commonly seen in cities under the prefectural level. This partly explained the negative impacts of TA on PM 2.5 level changes, as an expanded while unoccupied or non-industrialized urban zones may lower the average PM 2.5 concentration within the city boundary, but it doesn’t necessarily mean that the air quality got improved in the city cores.

Aggregation metrics at the landscape scale is often referred to as landscape texture that quantifies the tendency of patch types to be spatially aggregated; i.e., broadly speaking, aggregated or “contagious” distributions. This group of metrics is most effective in capturing the PM 2.5 trends in mid-sized cities (population range 25–50 k) and Central China, where the urbanization process is still undergoing. The three significant variables that reflect the spatial property of dispersion, separately landscape shape index, patch cohesion index, and aggregation index, consistently indicate that more aggregated landscape results in a higher degree of PM 2.5 level changes. Theoretically, the more compact urban form typically leads to less auto dependence and heavier reliance on the usage of public transit and walking, which contributes to air pollution mitigation 89 . This phenomenon has also been observed in China, as the vehicle-use intensity (kilometers traveled per vehicle per year, VKT) has been declining over recent years 90 . However, VKT only represents the travel intensity of one car and does not reflect the total distance traveled that cumulatively contribute to the local pollution. It should be noted that the private light-duty vehicle ownership in China has increased exponentially and is forecast to reach 23–42 million by 2050, with the share of new-growth purchases representing 16–28% 90 . In this case, considering the increased total distance traveled, the less dispersed urban form can exert negative effects on air quality by concentrating vehicle pollution emissions in a limited space.

Finally, urban contiguity, observed as the most effective shape metric in indicating PM 2.5 level changes, provides an assessment of spatial connectedness across all urban patches. Urban contiguity is found to have a positive effect on the long-term PM 2.5 pollution changes in large cities. Urban contiguity reflects to which degree the urban landscape is fragmented. Large contiguous patches result in large CONTIG_MN values. Among the 626 cities, only 11% of cities experience negative changes in urban contiguity. For example, Qingyang, Gansu is one of the cities-featuring leapfrogs and scattered development separated by vacant land that may later be filled in as the development continues (Fig.  6 ). Most Chinese cities experienced increased urban contiguity, with less fragmented and compacted landscape. A typical example is Shenzhou, Hebei, where CONTIG_MN rose from 0.27 to 0.45 within the 14 years. Although the 13 counties in Shenzhou are very far scattered from each other, each county is growing intensively internally rather than sprawling further outside. And its urban layout is thus more compact (Fig.  6 ). The positive association revealed in this study contradicts a global study indicating that cities with highly contiguous built-up areas have lower NO 2 pollution 22 . We noticed that the principal emission sources of NO 2 differ from that of PM 2.5. NO 2 is primarily emitted with the combustion of fossil fuels (e.g., industrial processes and power generation) 6 , whereas road traffic attributes more to PM 2.5 emissions. Highly connected urban form is likely to cause traffic congestion and trap pollution inside the street canyon, which accumulates higher PM 2.5 concentration. Computer simulation results also indicate that more compact cities improve urban air quality but are under the premise that mixed land use should be presented 18 . With more connected impervious surfaces, it is merely impossible to expect increasing urban green spaces. If compact urban development does not contribute to a rising proportion of green areas, then such a development does not help mitigating air pollution 41 .

Six cities illustrating negative to positive changes in CONTIG_MN and AREA_MN. Pixels in black show the urban areas in the year 2000 and pixels in red are the expanded urban areas from the year 2000 to 2014. Figure was produced by ArcGIS 10.7.1 85 .

Conclusions

This study explores the regional land-use patterns and air quality in a country with an extraordinarily heterogeneous urbanization pattern. Our study is the first of its kind in investigating such a wide range selection of cities ranging from small-sized ones to large metropolitan areas spanning a long time frame, to gain a comprehensive insight into the varying effects of urban form on air quality trends. And the primary insight yielded from this study is the validation of the hypothesis that the determinants of PM 2.5 level trends are not the same for cities at various developmental levels or in different geographic regions. Certain measures of urban form are robust predictors of air quality trends for a certain group of cities. Therefore, any planning strategy aimed at reducing air pollution should consider its current development status and based upon which, design its future plan. To this end, it is also important to emphasize the main shortcoming of this analysis, which is generally centered around the selection of control variables. This is largely constrained by the available information from the City Statistical Yearbook. It will be beneficial to further polish this study by including other important controlling factors, such as vehicle possession.

Lim, C. C. et al. Association between long-term exposure to ambient air pollution and diabetes mortality in the US. Environ. Res. 165 , 330–336 (2018).

Article   CAS   PubMed   PubMed Central   Google Scholar  

Yang, J. & Zhang, B. Air pollution and healthcare expenditure: implication for the benefit of air pollution control in China. Environ. Int. 120 , 443–455 (2018).

Article   PubMed   Google Scholar  

Bell, J. N. B., Power, S. A., Jarraud, N., Agrawal, M. & Davies, C. The effects of air pollution on urban ecosystems and agriculture. Int. J. Sust. Dev. World 18 (3), 226–235 (2011).

Article   Google Scholar  

Matus, K. et al. Health damages from air pollution in China. Glob. Environ. Change 22 (1), 55–66 (2012).

Bereitschaft, B. & Debbage, K. Urban form, air pollution, and CO 2 emissions in large US metropolitan areas. Prof Geogr. 65 (4), 612–635 (2013).

Bozkurt, Z., Üzmez, Ö. Ö., Döğeroğlu, T., Artun, G. & Gaga, E. O. Atmospheric concentrations of SO2, NO2, ozone and VOCs in Düzce, Turkey using passive air samplers: sources, spatial and seasonal variations and health risk estimation. Atmos. Pollut. Res. 9 (6), 1146–1156 (2018).

Article   CAS   Google Scholar  

Fang, C., Liu, H., Li, G., Sun, D. & Miao, Z. Estimating the impact of urbanization on air quality in China using spatial regression models. Sustainability 7 (11), 15570–15592 (2015).

Khaniabadi, Y. O. et al. Mortality and morbidity due to ambient air pollution in Iran. Clin. Epidemiol. Glob. Health 7 (2), 222–227 (2019).

Health Effects Institute. State of Global Air 2019 . Special Report (Health Effects Institute, Boston, 2019). ISSN 2578-6873.

O’Meara, M. & Peterson, J. A. Reinventing Cities for People and the Planet (Worldwatch Institute, Washington, 1999).

Google Scholar  

World Health Organization. Ambient Air Pollution: A Global Assessment of Exposure and Burden of Disease . ISBN: 9789241511353 (2016).

Liu, C. et al. Ambient particulate air pollution and daily mortality in 652 cities. N. Engl. J. Med. 381 (8), 705–715 (2019).

Anderson, W. P., Kanaroglou, P. S. & Miller, E. J. Urban form, energy and the environment: a review of issues, evidence and policy. Urban Stud. 33 (1), 7–35 (1996).

Hart, R., Liang, L. & Dong, P. L. Monitoring, mapping, and modeling spatial–temporal patterns of PM2.5 for improved understanding of air pollution dynamics using portable sensing technologies. Int. J. Environ. Res. Public Health . 17 (14), 4914 (2020).

Article   PubMed Central   Google Scholar  

Environmental Protection Agency. Our Built and Natural Environments: A Technical Review of the Interactions Between Land Use, Transportation and Environmental Quality (2nd edn.). Report 231K13001 (Environmental Protection Agency, Washington, 2013).

Chen, M., Zhang, H., Liu, W. & Zhang, W. The global pattern of urbanization and economic growth: evidence from the last three decades. PLoS ONE 9 (8), e103799 (2014).

Article   ADS   PubMed   PubMed Central   CAS   Google Scholar  

Wang, S., Liu, X., Zhou, C., Hu, J. & Ou, J. Examining the impacts of socioeconomic factors, urban form, and transportation networks on CO 2 emissions in China’s megacities. Appl. Energy. 185 , 189–200 (2017).

Borrego, C. et al. How urban structure can affect city sustainability from an air quality perspective. Environ. Model. Softw. 21 (4), 461–467 (2006).

Bart, I. Urban sprawl and climate change: a statistical exploration of cause and effect, with policy options for the EU. Land Use Policy 27 (2), 283–292 (2010).

Feng, H., Zou, B. & Tang, Y. M. Scale- and region-dependence in landscape-PM 2.5 correlation: implications for urban planning. Remote Sens. 9 , 918. https://doi.org/10.3390/rs9090918 (2017).

Rodríguez, M. C., Dupont-Courtade, L. & Oueslati, W. Air pollution and urban structure linkages: evidence from European cities. Renew. Sustain. Energy Rev. 53 , 1–9 (2016).

Bechle, M. J., Millet, D. B. & Marshall, J. D. Effects of income and urban form on urban NO2: global evidence from satellites. Environ. Sci. Technol. 45 (11), 4914–4919 (2011).

Article   ADS   CAS   PubMed   Google Scholar  

Martins, H., Miranda, A. & Borrego, C. Urban structure and air quality. In Air Pollution-A Comprehensive Perspective (2012).

Stone, B. Jr. Urban sprawl and air quality in large US cities. J. Environ. Manag. 86 (4), 688–698 (2008).

Breheny, M. Densities and sustainable cities: the UK experience. In Cities for the new millennium , 39–51 (2001).

Glaeser, E. L. & Kahn, M. E. Sprawl and urban growth. In Handbook of regional and urban economics , vol. 4, 2481–2527 (Elsevier, Amsterdam, 2004).

Manins, P. C. et al. The impact of urban development on air quality and energy use. Clean Air 18 , 21 (1998).

Troy, P. N. Environmental stress and urban policy. The compact city: a sustainable urban form, 200–211 (1996).

Gaigné, C., Riou, S. & Thisse, J. F. Are compact cities environmentally friendly?. J. Urban Econ. 72 (2–3), 123–136 (2012).

Wood, C. Air pollution control by land use planning techniques: a British-American review. Int. J. Environ. Stud. 35 (4), 233–243 (1990).

Zhou, B., Rybski, D. & Kropp, J. P. The role of city size and urban form in the surface urban heat island. Sci. Rep. 7 (1), 4791 (2017).

Sarrat, C., Lemonsu, A., Masson, V. & Guedalia, D. Impact of urban heat island on regional atmospheric pollution. Atmos. Environ. 40 (10), 1743–1758 (2006).

Article   ADS   CAS   Google Scholar  

Liu, Y., Wu, J., Yu, D. & Ma, Q. The relationship between urban form and air pollution depends on seasonality and city size. Environ. Sci. Pollut. Res. 25 (16), 15554–15567 (2018).

Cavalcante, R. M. et al. Influence of urbanization on air quality based on the occurrence of particle-associated polycyclic aromatic hydrocarbons in a tropical semiarid area (Fortaleza-CE, Brazil). Air Qual. Atmos. Health. 10 (4), 437–445 (2017).

Han, L., Zhou, W. & Li, W. Fine particulate (PM 2.5 ) dynamics during rapid urbanization in Beijing, 1973–2013. Sci. Rep. 6 , 23604 (2016).

Article   ADS   CAS   PubMed   PubMed Central   Google Scholar  

Tuo, Y., Li, X. & Wang, J. Negative effects of Beijing’s air pollution caused by urbanization on residents’ health. In 2nd International Conference on Science and Social Research (ICSSR 2013) , 732–735 (Atlantis Press, 2013).

Zhou, C. S., Li, S. J. & Wang, S. J. Examining the impacts of urban form on air pollution in developing countries: a case study of China’s megacities. Int. J. Environ. Res. Public Health. 15 (8), 1565 (2018).

Article   PubMed Central   CAS   Google Scholar  

Cariolet, J. M., Colombert, M., Vuillet, M. & Diab, Y. Assessing the resilience of urban areas to traffic-related air pollution: application in Greater Paris. Sci. Total Environ. 615 , 588–596 (2018).

She, Q. et al. Air quality and its response to satellite-derived urban form in the Yangtze River Delta, China. Ecol. Indic. 75 , 297–306 (2017).

Yang, D. et al. Global distribution and evolvement of urbanization and PM 2.5 (1998–2015). Atmos. Environ. 182 , 171–178 (2018).

Cho, H. S. & Choi, M. Effects of compact urban development on air pollution: empirical evidence from Korea. Sustainability 6 (9), 5968–5982 (2014).

Li, C., Wang, Z., Li, B., Peng, Z. R. & Fu, Q. Investigating the relationship between air pollution variation and urban form. Build. Environ. 147 , 559–568 (2019).

Montgomery, M. R. The urban transformation of the developing world. Science 319 (5864), 761–764 (2008).

United Nations. World Urbanization Prospects: The 2009 Revision (United Nations Publication, New York, 2010).

Jiang, L. & O’Neill, B. C. Global urbanization projections for the shared socioeconomic pathways. Glob. Environ. Change 42 , 193–199 (2017).

Martine, G., McGranahan, G., Montgomery, M. & Fernandez-Castilla, R. The New Global Frontier: Urbanization, Poverty and Environment in the 21st Century (Earthscan, London, 2008).

Gong, P., Li, X. C. & Zhang, W. 40-Year (1978–2017) human settlement changes in China reflected by impervious surfaces from satellite remote sensing. Sci. Bull. 64 (11), 756–763 (2019).

Center for International Earth Science Information Network—CIESIN—Columbia University, C. I.-C.-I.. Global Rural–Urban Mapping Project, Version 1 (GRUMPv1): Urban Extent Polygons, Revision 01 . Palisades, NY: NASA Socioeconomic Data and Applications Center (SEDAC) (2017). https://doi.org/10.7927/H4Z31WKF . Accessed 10 April 2020.

Balk, D. L. et al. Determining global population distribution: methods, applications and data. Adv Parasit. 62 , 119–156. https://doi.org/10.1016/S0065-308X(05)62004-0 (2006).

Chinese Academy of Surveying and Mapping—CASM China in Time and Space—CITAS—University of Washington, a. C.-C. (1996). China Dimensions Data Collection: China Administrative Regions GIS Data: 1:1M, County Level, 1 July 1990 . Palisades, NY: NASA Socioeconomic Data and Applications Center (SEDAC). https://doi.org/10.7927/H4GT5K3V . Accessed 10 April 2020.

Ma, L. J. Urban administrative restructuring, changing scale relations and local economic development in China. Polit. Geogr. 24 (4), 477–497 (2005).

Article   MathSciNet   Google Scholar  

Van Donkelaar, A. et al. Global estimates of fine particulate matter using a combined geophysical-statistical method with information from satellites, models, and monitors. Environ. Sci. Technol. 50 (7), 3762–3772 (2016).

Article   ADS   PubMed   CAS   Google Scholar  

Gong, P. et al. Annual maps of global artificial impervious area (GAIA) between 1985 and 2018. Remote Sens. Environ 236 , 111510 (2020).

Article   ADS   Google Scholar  

Li, X. C., Gong, P. & Liang, L. A 30-year (1984–2013) record of annual urban dynamics of Beijing City derived from Landsat data. Remote Sens. Environ. 166 , 78–90 (2015).

Li, X. C. & Gong, P. An, “exclusion-inclusion” framework for extracting human settlements in rapidly developing regions of China from Landsat images. Remote Sens. Environ. 186 , 286–296 (2016).

National Bureau of Statistics 2000–2014. China City Statistical Yearbook (China Statistics Press). ISBN: 978-7-5037-6387-8

Lai, A. C., Thatcher, T. L. & Nazaroff, W. W. Inhalation transfer factors for air pollution health risk assessment. J. Air Waste Manag. Assoc. 50 (9), 1688–1699 (2000).

Article   CAS   PubMed   Google Scholar  

Luo, Y. et al. Relationship between air pollutants and economic development of the provincial capital cities in China during the past decade. PLoS ONE 9 (8), e104013 (2014).

Hart, R., Liang, L. & Dong, P. Monitoring, mapping, and modeling spatial–temporal patterns of PM2.5 for improved understanding of air pollution dynamics using portable sensing technologies. Int. J. Environ. Res. Public Health 17 (14), 4914 (2020).

Wang, X. & Zhang, R. Effects of atmospheric circulations on the interannual variation in PM2.5 concentrations over the Beijing–Tianjin–Hebei region in 2013–2018. Atmos. Chem. Phys. 20 (13), 7667–7682 (2020).

Xu, Y. et al. Impact of meteorological conditions on PM 2.5 pollution in China during winter. Atmosphere 9 (11), 429 (2018).

Hernandez, G., Berry, T.A., Wallis, S. & Poyner, D. Temperature and humidity effects on particulate matter concentrations in a sub-tropical climate during winter. In Proceedings of the International Conference of the Environment, Chemistry and Biology (ICECB 2017), Queensland, Australia, 20–22 November 2017; Juan, L., Ed.; IRCSIT Press: Singapore, 2017.

Zhang, Y. Dynamic effect analysis of meteorological conditions on air pollution: a case study from Beijing. Sci. Total. Environ. 684 , 178–185 (2019).

National Earth System Science Data Center. National Science & Technology Infrastructure of China . https://www.geodata.cn . Accessed 6 Oct 2020.

Bhatta, B., Saraswati, S. & Bandyopadhyay, D. Urban sprawl measurement from remote sensing data. Appl. Geogr. 30 (4), 731–740 (2010).

Dietzel, C., Oguz, H., Hemphill, J. J., Clarke, K. C. & Gazulis, N. Diffusion and coalescence of the Houston Metropolitan Area: evidence supporting a new urban theory. Environ. Plan. B Plan. Des. 32 (2), 231–246 (2005).

Li, S., Zhou, C., Wang, S. & Hu, J. Dose urban landscape pattern affect CO2 emission efficiency? Empirical evidence from megacities in China. J. Clean. Prod. 203 , 164–178 (2018).

Gyenizse, P., Bognár, Z., Czigány, S. & Elekes, T. Landscape shape index, as a potencial indicator of urban development in Hungary. Acta Geogr. Debrecina Landsc. Environ. 8 (2), 78–88 (2014).

Rutledge, D. T. Landscape indices as measures of the effects of fragmentation: can pattern reflect process? DOC Science Internal Series . ISBN 0-478-22380-3 (2003).

Mcgarigal, K. & Marks, B. J. Spatial pattern analysis program for quantifying landscape structure. Gen. Tech. Rep. PNW-GTR-351. US Department of Agriculture, Forest Service, Pacific Northwest Research Station, 1–122 (1995).

Chan, C. K. & Yao, X. Air pollution in mega cities in China. Atmos. Environ. 42 (1), 1–42 (2008).

Anselin, L. The Moran Scatterplot as an ESDA Tool to Assess Local Instability in Spatial Association. In Spatial Analytical Perspectives on Gis in Environmental and Socio-Economic Sciences (eds Fischer, M. et al. ) 111–125 (Taylor; Francis, London, 1996).

Zou, B., Peng, F., Wan, N., Mamady, K. & Wilson, G. J. Spatial cluster detection of air pollution exposure inequities across the United States. PLoS ONE 9 (3), e91917 (2014).

Bone, C., Wulder, M. A., White, J. C., Robertson, C. & Nelson, T. A. A GIS-based risk rating of forest insect outbreaks using aerial overview surveys and the local Moran’s I statistic. Appl. Geogr. 40 , 161–170 (2013).

Anselin, L., Syabri, I. & Kho, Y. GeoDa: an introduction to spatial data analysis. Geogr. Anal. 38 , 5–22 (2006).

R Core Team. R A Language and Environment for Statistical Computing (R Foundation for Statistical Computing, Vienna, 2013).

Cole, M. A. & Neumayer, E. Examining the impact of demographic factors on air pollution. Popul. Environ. 26 (1), 5–21 (2004).

Liu, Y., Arp, H. P. H., Song, X. & Song, Y. Research on the relationship between urban form and urban smog in China. Environ. Plan. B Urban Anal. City Sci. 44 (2), 328–342 (2017).

York, R., Rosa, E. A. & Dietz, T. STIRPAT, IPAT and ImPACT: analytic tools for unpacking the driving forces of environmental impacts. Ecol. Econ. 46 (3), 351–365 (2003).

United Nations, Department of Economic and Social Affairs Population Division 2011: the 2010 Revision (United Nations Publications, New York, 2011)

Ahn, S. C. & Schmidt, P. Efficient estimation of models for dynamic panel data. J. Econ. 68 (1), 5–27 (1995).

Article   MathSciNet   MATH   Google Scholar  

Du, L., Wei, C. & Cai, S. Economic development and carbon dioxide emissions in China: provincial panel data analysis. China Econ. Rev. 23 (2), 371–384 (2012).

Hausman, J. A. Specification tests in econometrics. Econ. J. Econ. Soc. 46 (6), 1251–1271 (1978).

Greene, W. H. Econometric Analysis (Pearson Education India, New Delhi, 2003).

ArcGIS GIS 10.7.1. (Environmental Systems Research Institute, Inc., Redlands, 2010).

Lao, X., Shen, T. & Gu, H. Prospect on China’s urban system by 2020: evidence from the prediction based on internal migration network. Sustainability 10 (3), 654 (2018).

Henderson, J.V., Logan, J.R. & Choi, S. Growth of China's medium-size cities . Brookings-Wharton Papers on Urban Affairs, 263–303 (2005).

Lu, H., Zhang, C., Liu, G., Ye, X. & Miao, C. Mapping China’s ghost cities through the combination of nighttime satellite data and daytime satellite data. Remote Sens. 10 (7), 1037 (2018).

Frank, L. D. et al. Many pathways from land use to health: associations between neighborhood walkability and active transportation, body mass index, and air quality. JAPA. 72 (1), 75–87 (2006).

Huo, H. & Wang, M. Modeling future vehicle sales and stock in China. Energy Policy 43 , 17–29 (2012).

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Acknowledgements

Lu Liang received intramural research funding support from the UNT Office of Research and Innovation. Peng Gong is partially supported by the National Research Program of the Ministry of Science and Technology of the People’s Republic of China (2016YFA0600104), and donations from Delos Living LLC and the Cyrus Tang Foundation to Tsinghua University.

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Liang, L., Gong, P. Urban and air pollution: a multi-city study of long-term effects of urban landscape patterns on air quality trends. Sci Rep 10 , 18618 (2020). https://doi.org/10.1038/s41598-020-74524-9

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A cloak of smog gives Fresno, California, a hazy look. Smog, a hybrid of the words "smoke" and "fog," is caused when sunlight reacts with airborne pollution, including ash, dust, and ground-level ozone.

Urban Threats

Urbanization spurs a unique set of issues to both humans and animals.

The promise of jobs and prosperity, among other factors, pulls people to cities. Half of the global population already lives in cities, and by 2050 two-thirds of the world's people are expected to live in urban areas. But in cities two of the most pressing problems facing the world today also come together: poverty and environmental degradation.

Poor air and water quality, insufficient water availability, waste-disposal problems, and high energy consumption are exacerbated by the increasing population density and demands of urban environments. Strong city planning will be essential in managing these and other difficulties as the world's urban areas swell.

• Intensive urban growth can lead to greater poverty, with local governments unable to provide services for all people.
• Concentrated energy use leads to greater air pollution with significant impact on human health.
• Automobile exhaust produces elevated lead levels in urban air.
• Large volumes of uncollected waste create multiple health hazards.
• Urban development can magnify the risk of environmental hazards such as flash flooding .
• Pollution and physical barriers to root growth promote loss of urban tree cover.
• Animal populations are inhibited by toxic substances, vehicles, and the loss of habitat and food sources.
• Combat poverty by promoting economic development and job creation.
• Involve local community in local government.
• Reduce air pollution by upgrading energy use and alternative transport systems.
• Create private-public partnerships to provide services such as waste disposal and housing.
• Plant trees and incorporate the care of city green spaces as a key element in urban planning.

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• Pollution Due to Urbanisation Essay

Essay on Pollution Due to Urbanisation

Below, you will find an essay on pollution due to urbanisation (long) and also a short essay on pollution due to urbanisation. While urbanisation has its positives, it is imperative to look at every object according to its pros and cons. Here are two essays on pollution due to urbanisation of 400-500 words and 100-200 words, respectively. We will discuss the importance of urbanisation for countries, and how urbanisation is polluting the world.

Long Essay on Pollution Due to Urbanisation

Urbanisation is a great concept which is required to develop any country. It refers to the concept of urbanising remote areas by building infrastructure which then brings about development. Infrastructure refers to all the buildings and institutions which are necessary for economic development to take place in an area. For example, educational institutions like schools, colleges, vocational learning centres are part of the infrastructure. Healthcare facilities such as hospitals and clinics, employment opportunities, food security, etc. are also part of the infrastructure of a country.

It is seen very often that a big corporation sets up shop in a rural area, and around this, infrastructure is built, and development and urbanisation take place. Jamshedpur is an example of such a place, where Tata Industries set up shop many years ago and made the area highly developed. Thus, urbanisation definitely encourages the people of a place to have a better life by giving them more opportunities to achieve good life through education, jobs, etc.

On the other hand, it must be duly noted that urbanisation is one of the leading causes of pollution in today’s world. There are several different kinds of pollution, such as air pollution, water pollution, soil pollution and noise pollution. The facets of urbanisation contribute to each one of these types of pollution in one way or another. Factories and mines contribute to air pollution through the fumes that each of them emits into the air. The damage done to the water and soil around factories because of their flowing septic is harmful to both humans as well as aquatic life. Additionally, the noises that come from mines, the whirring of machinery in factories, etc. contribute to noise pollution.

Additionally, it is not only big industries that contribute to pollution due to urbanisation. Part of urbanisation is also the development of roads, which means more cars, buses, two-wheelers, three-wheelers, trucks, etc. on the road. These all contribute to noise pollution because of the incessant honking, and also to air pollution, because of the fumes that all motor vehicles emit. Even when we are stuck in traffic in an auto, it becomes difficult to breathe because of the fumes which surround us on the roads. If we are finding it difficult to breathe, imagine what so many fumes are doing to our planet.

Short Essay on Pollution Due to Urbanisation

150 Words Paragraph On Pollution Due to Urbanisation

Pollution takes place when air, water or soil becomes contaminated with unwanted substances. Air pollution takes place because of the fumes of factories and motor vehicles on th e road. Soil pollution and water pollution take place due to the septic waste being released into soil or water that surrounds a factory. Even oil spills are a major reason for water pollution, and all kinds of pollution can be very dangerous for living beings. Another type of pollution is noise pollution, which comes from the honking of cars, loud sounds in factories, the passing of aeroplanes and trains, etc.

Urbanisation is a result of the need to achieve economic development. It refers to when a relatively rural or remote area is made more urban by constructing roads, hospitals, schools, offices, etc. In this way, development is a result of urbanisation, which is extremely good for all countries.

However, all the great factors that urbanisation brings in, such as factories to work in, motor vehicles to drive, and so much more, all of these contribute to pollution more and more. Even though urbanisation is very important for a country, it is important to address all the kinds of pollution

Pollution is one of the most pressing concerns confronting our civilization today. When their environment deteriorates on a daily basis, humans face major challenges. The mixing of any toxic element or contaminants in our natural environment is referred to as pollution. Many contaminants are introduced into the natural environment as a result of human activities, contaminating it too dangerous proportions. Pollution is caused by a variety of factors, one of which is urbanisation.

The negative aspect of urbanisation is the manufacturers, which emit a great deal of pollution. Their equipment emits smoke into the environment, pollutes water streams and the surrounding land, and makes a lot of noise. As a result, there is a lot of pollution as a result of urbanisation, and it is extremely destructive to the environment when it first begins.

The majority of the pollution in our environment is due to urbanisation. It's because factories are springing up all over the place, there are a lot more cars on the road now, and so on.

Pollution Due to Urbanisation

Our mother planet is choking, and we are unable to do anything about it. Today, we confront several issues, one of which is pollution. Pollution occurs when a contaminating substance is introduced into our environment and pollutes our natural resources. There are numerous causes of pollution, most of which are caused by humans. Natural resources and habitats have been depleted as a result of our activities.

Urbanisation is one of the primary causes of human pollution. Pollution levels began to rise when humans began to construct cities and industrialization developed. Human needs continue to expand, and we loot our mother planet to meet them. As a result of development, many beautiful valleys, mountains, hilltop stations, and woods have become pollution carriers. Trees have been felled, rivers and lakes have been poisoned, and natural reserves have been exploited.

As a result, we now live in severely polluted cities where daily life has become increasingly challenging. As a result of urban pollution, we are experiencing a variety of health issues, the worst part of which is that we are fully unconscious of it. It is past time for us to take steps to reduce pollution and make the world a better place for future generations.

Urbanisation is a really great step forward for any country, and it is and should be the main aim of all countries. All people around the world should have access to proper healthcare, education, sanitation, nourishment and safety, and urbanisation is how we can help achieve this goal. However, in the process of meeting this goal, we cannot forget that pollution due to urbanisation does take place, and is very dangerous for the planet and, therefore, all species living on earth in the long run.

FAQs on Pollution Due to Urbanisation Essay

1. What are the pros and cons of urbanisation according to the essay on pollution due to urbanisation?

The essay on pollution due to urbanisation says that urbanisation is good and is vital for a country, but can also be harmful for the environment. Urbanisation brings in better education, better healthcare facilities, better roads, and better infrastructure in general. However, it improves the lifestyles of human beings at the cost of hurting the environment by putting more contaminants into air, water and soil in the form of toxic fumes and septic waste. Thus, urbanisation is important, but it has to be brought about in a more sustainable manner.

2. How can we reduce pollution due to urbanisation?

At the individual level, there are some very simple ways to reduce pollution due to urbanisation. To reduce air pollution, we can choose to walk, carpool, or use public transport instead of taking a taxi. Garbage should not be thrown on roads and in water bodies, in order for us to stop soil and water pollution. We should also not honk on roads unnecessarily, to curb noise pollution. Unless the big companies and industries do not decide to take a stand and do what’s good for the environment, we will have to keep relying only on individual measures.

3. What are the different types of pollution and their causes?

Pollution in Cities: Types and Causes

Air Pollution: The air in metropolitan places is constantly polluted with harmful compounds, making breathing increasingly dangerous. The air in cities is suffocating. The air is polluted by smoke from autos, factories, and power plants. There are also other contaminants in the air, such as chemical spills and other harmful substances.

Water Pollution: Natural water supplies are becoming increasingly scarce in metropolitan areas, and those that do exist are becoming progressively contaminated. There is a lot of waste dumping in lakes and rivers, such as residential and industrial waste. A lot of trash is washed into the rivers when it rains.

Soil Pollution: Toxic mixtures in the soil are causing ecosystem disruption.

Noise Pollution: Cities are among the noisiest places on the planet. Noise pollution is caused by a variety of sources, including traffic noises, loudspeakers, and other undesirable noises, which cause a variety of health problems.

Radioactive Pollution:   Nuclear power facilities' unintentional leaks represent a serious concern.

Visual Pollution: Signs, billboards, screens, high-intensity lights, and other forms of overexposure to sights in cities can also be highly unsettling.

There is also ' Thermal pollution ,' which is created by an excess of heat trapped in the earth's atmosphere.

4. How can pollution due to urbanisation be controlled?

One can implement the following methods to reduce pollution caused by urbanisation: 

Conserve Energy: People in urban areas always use more energy than people in rural areas. The use of energy results in numerous types of pollution. One of the most effective strategies to reduce pollution is to conserve energy wherever possible. When you are not using an electrical appliance, turn it off. This tiny step can make a tremendous difference.

Reduce water waste: We waste a lot of water on a daily basis, which might have negative implications. We must make every effort to utilize as little water as possible.

Plant more trees: Urban areas are the ones with the least amount of greenery. It's a good idea to have a kitchen garden and a little lawn near your house.

Green belts: The government can assist by declaring specific sections in each city as green belts, allowing trees and other plants to flourish freely.

Use fewer loudspeakers: Using fewer loudspeakers can significantly minimise noise pollution. It's also a good idea to turn down the music level at functions after a specific amount of time has passed.

Indoors: In cities, home interiors are likewise heavily contaminated. We must also have some plants inside our homes to filter the polluted indoor air.

Industrial trash: Factory owners must make every effort to avoid dumping industrial waste in lakes or rivers. The government can also enact legislation in this regard.

5.  What problems are caused due to Urbanization?

The necessity for open space to develop roads, buildings, and bridges, among other things, resulted in widespread deforestation. To accommodate the ever-increasing population, trees were cut down, fields were cleared, and built new space. It goes without saying that tree cutting is a major source of pollution. The high population density resulted in a scarcity of everything, including space and natural resources such as water and coal.

A number of serious challenges have arisen as a result of the interaction of the urban population with the environment. The spending habits and lifestyles of the urban people had a significant impact on the environment. Consumption of food, energy, and water is all higher in cities. Cities have much more filthy air than rural areas. This is mainly due to the increased use of automobiles and the expansion of industries and factories that pollute the air.  We utilise electricity to power almost all of our equipment.

6. What is urbanisation, and how is it caused?

The population shift from rural to urban regions, the resulting decline in the number of people living in rural areas, and the methods in which societies adjust to this transition are all referred to as urbanisation. It is basically the process by which towns and cities evolve and grow as more people choose to live and work in central locations.

Individual, community and state activity result in either organic or planned urbanisation. Living in a city can be culturally and economically advantageous since it can provide more options for access to the labour market, better education, housing, and safety conditions, as well as lower commute and transit time and costs. A healthy urban environment is characterised by density, proximity, diversity, and marketplace rivalry. However, there are also negative social consequences associated with urban living, such as alienation, stress, higher living costs, and mass marginalisation. Suburbanization, which is occurring in the greatest developing countries' cities, can be seen as an attempt to balance these negative aspects of city living while still giving access to a huge number of shared resources.

7. What is the Impact of Urbanisation in Indian Cities?

The following are the main effects of urbanisation on environmental quality in Indian cities:

According to the entire slum population in India in 1991, 41 per cent of the overall slum population lived in cities with populations of one million or more, which account for 27 percent of the country's total population.

According to the current situation of municipal solid trash creation and collection situation in Indian metropolitan cities, Maharashtra creates the most municipal solid garbage (11,000 tonnes per day), followed by Delhi (8700 tonnes per day) in 2019, both of which are expected to rise in the near future.

In India and other Metropolitan Cities, the number of automobiles on the road is increasing.

In India and other metropolitan cities, the number of automobiles on the road has increased. The usage of vehicles has increased by 10% or more on average, posing a significant threat to air pollution.

Water resources are dwindling day by day as a result of rising population, wasteful usage, and a lack of conservation. Huge amounts of wastewater enter rivers as cities and industries grow, contaminating river streams that are used for drinking and other reasons.

Pollution is the introduction of harmful materials into the environment. These harmful materials are called pollutants.

Biology, Ecology, Health, Earth Science, Geography

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Pollution is the introduction of harmful materials into the environment . These harmful materials are called pollutants . Pollutants can be natural, such as volcanic ash . They can also be created by human activity, such as trash or runoff produced by factories. Pollutants damage the quality of air, water, and land. Many things that are useful to people produce pollution. Cars spew pollutants from their exhaust pipes. Burning coal to create electricity pollutes the air. Industries and homes generate garbage and sewage that can pollute the land and water. Pesticides —chemical poisons used to kill weeds and insects— seep into waterways and harm wildlife . All living things—from one-celled microbes to blue whales—depend on Earth ’s supply of air and water. When these resources are polluted, all forms of life are threatened. Pollution is a global problem. Although urban areas are usually more polluted than the countryside, pollution can spread to remote places where no people live. For example, pesticides and other chemicals have been found in the Antarctic ice sheet . In the middle of the northern Pacific Ocean, a huge collection of microscopic plastic particles forms what is known as the Great Pacific Garbage Patch . Air and water currents carry pollution. Ocean currents and migrating fish carry marine pollutants far and wide. Winds can pick up radioactive material accidentally released from a nuclear reactor and scatter it around the world. Smoke from a factory in one country drifts into another country. In the past, visitors to Big Bend National Park in the U.S. state of Texas could see 290 kilometers (180 miles) across the vast landscape . Now, coal-burning power plants in Texas and the neighboring state of Chihuahua, Mexico have spewed so much pollution into the air that visitors to Big Bend can sometimes see only 50 kilometers (30 miles). The three major types of pollution are air pollution , water pollution , and land pollution . Air Pollution Sometimes, air pollution is visible . A person can see dark smoke pour from the exhaust pipes of large trucks or factories, for example. More often, however, air pollution is invisible . Polluted air can be dangerous, even if the pollutants are invisible. It can make people’s eyes burn and make them have difficulty breathing. It can also increase the risk of lung cancer . Sometimes, air pollution kills quickly. In 1984, an accident at a pesticide plant in Bhopal, India, released a deadly gas into the air. At least 8,000 people died within days. Hundreds of thou sands more were permanently injured. Natural disasters can also cause air pollution to increase quickly. When volcanoes erupt , they eject volcanic ash and gases into the atmosphere . Volcanic ash can discolor the sky for months. After the eruption of the Indonesian volcano of Krakatoa in 1883, ash darkened the sky around the world. The dimmer sky caused fewer crops to be harvested as far away as Europe and North America. For years, meteorologists tracked what was known as the “equatorial smoke stream .” In fact, this smoke stream was a jet stream , a wind high in Earth’s atmosphere that Krakatoa’s air pollution made visible. Volcanic gases , such as sulfur dioxide , can kill nearby residents and make the soil infertile for years. Mount Vesuvius, a volcano in Italy, famously erupted in 79, killing hundreds of residents of the nearby towns of Pompeii and Herculaneum. Most victims of Vesuvius were not killed by lava or landslides caused by the eruption. They were choked, or asphyxiated , by deadly volcanic gases. In 1986, a toxic cloud developed over Lake Nyos, Cameroon. Lake Nyos sits in the crater of a volcano. Though the volcano did not erupt, it did eject volcanic gases into the lake. The heated gases passed through the water of the lake and collected as a cloud that descended the slopes of the volcano and into nearby valleys . As the toxic cloud moved across the landscape, it killed birds and other organisms in their natural habitat . This air pollution also killed thousands of cattle and as many as 1,700 people. Most air pollution is not natural, however. It comes from burning fossil fuels —coal, oil , and natural gas . When gasoline is burned to power cars and trucks, it produces carbon monoxide , a colorless, odorless gas. The gas is harmful in high concentrations , or amounts. City traffic produces highly concentrated carbon monoxide. Cars and factories produce other common pollutants, including nitrogen oxide , sulfur dioxide, and hydrocarbons . These chemicals react with sunlight to produce smog , a thick fog or haze of air pollution. The smog is so thick in Linfen, China, that people can seldom see the sun. Smog can be brown or grayish blue, depending on which pollutants are in it. Smog makes breathing difficult, especially for children and older adults. Some cities that suffer from extreme smog issue air pollution warnings. The government of Hong Kong, for example, will warn people not to go outside or engage in strenuous physical activity (such as running or swimming) when smog is very thick.

When air pollutants such as nitrogen oxide and sulfur dioxide mix with moisture, they change into acids . They then fall back to earth as acid rain . Wind often carries acid rain far from the pollution source. Pollutants produced by factories and power plants in Spain can fall as acid rain in Norway. Acid rain can kill all the trees in a forest . It can also devastate lakes, streams, and other waterways. When lakes become acidic, fish can’t survive . In Sweden, acid rain created thousands of “ dead lakes ,” where fish no longer live. Acid rain also wears away marble and other kinds of stone . It has erased the words on gravestones and damaged many historic buildings and monuments . The Taj Mahal , in Agra, India, was once gleaming white. Years of exposure to acid rain has left it pale. Governments have tried to prevent acid rain by limiting the amount of pollutants released into the air. In Europe and North America, they have had some success, but acid rain remains a major problem in the developing world , especially Asia. Greenhouse gases are another source of air pollution. Greenhouse gases such as carbon dioxide and methane occur naturally in the atmosphere. In fact, they are necessary for life on Earth. They absorb sunlight reflected from Earth, preventing it from escaping into space. By trapping heat in the atmosphere, they keep Earth warm enough for people to live. This is called the greenhouse effect . But human activities such as burning fossil fuels and destroying forests have increased the amount of greenhouse gases in the atmosphere. This has increased the greenhouse effect, and average temperatures across the globe are rising. The decade that began in the year 2000 was the warmest on record. This increase in worldwide average temperatures, caused in part by human activity, is called global warming . Global warming is causing ice sheets and glaciers to melt. The melting ice is causing sea levels to rise at a rate of two millimeters (0.09 inches) per year. The rising seas will eventually flood low-lying coastal regions . Entire nations, such as the islands of Maldives, are threatened by this climate change . Global warming also contributes to the phenomenon of ocean acidification . Ocean acidification is the process of ocean waters absorbing more carbon dioxide from the atmosphere. Fewer organisms can survive in warmer, less salty waters. The ocean food web is threatened as plants and animals such as coral fail to adapt to more acidic oceans. Scientists have predicted that global warming will cause an increase in severe storms . It will also cause more droughts in some regions and more flooding in others. The change in average temperatures is already shrinking some habitats, the regions where plants and animals naturally live. Polar bears hunt seals from sea ice in the Arctic. The melting ice is forcing polar bears to travel farther to find food , and their numbers are shrinking. People and governments can respond quickly and effectively to reduce air pollution. Chemicals called chlorofluorocarbons (CFCs) are a dangerous form of air pollution that governments worked to reduce in the 1980s and 1990s. CFCs are found in gases that cool refrigerators, in foam products, and in aerosol cans . CFCs damage the ozone layer , a region in Earth’s upper atmosphere. The ozone layer protects Earth by absorbing much of the sun’s harmful ultraviolet radiation . When people are exposed to more ultraviolet radiation, they are more likely to develop skin cancer, eye diseases, and other illnesses. In the 1980s, scientists noticed that the ozone layer over Antarctica was thinning. This is often called the “ ozone hole .” No one lives permanently in Antarctica. But Australia, the home of more than 22 million people, lies at the edge of the hole. In the 1990s, the Australian government began an effort to warn people of the dangers of too much sun. Many countries, including the United States, now severely limit the production of CFCs. Water Pollution Some polluted water looks muddy, smells bad, and has garbage floating in it. Some polluted water looks clean, but is filled with harmful chemicals you can’t see or smell. Polluted water is unsafe for drinking and swimming. Some people who drink polluted water are exposed to hazardous chemicals that may make them sick years later. Others consume bacteria and other tiny aquatic organisms that cause disease. The United Nations estimates that 4,000 children die every day from drinking dirty water. Sometimes, polluted water harms people indirectly. They get sick because the fish that live in polluted water are unsafe to eat. They have too many pollutants in their flesh. There are some natural sources of water pollution. Oil and natural gas, for example, can leak into oceans and lakes from natural underground sources. These sites are called petroleum seeps . The world’s largest petroleum seep is the Coal Oil Point Seep, off the coast of the U.S. state of California. The Coal Oil Point Seep releases so much oil that tar balls wash up on nearby beaches . Tar balls are small, sticky pieces of pollution that eventually decompose in the ocean.

Human activity also contributes to water pollution. Chemicals and oils from factories are sometimes dumped or seep into waterways. These chemicals are called runoff. Chemicals in runoff can create a toxic environment for aquatic life. Runoff can also help create a fertile environment for cyanobacteria , also called blue-green algae . Cyanobacteria reproduce rapidly, creating a harmful algal bloom (HAB) . Harmful algal blooms prevent organisms such as plants and fish from living in the ocean. They are associated with “ dead zones ” in the world’s lakes and rivers, places where little life exists below surface water. Mining and drilling can also contribute to water pollution. Acid mine drainage (AMD) is a major contributor to pollution of rivers and streams near coal mines . Acid helps miners remove coal from the surrounding rocks . The acid is washed into streams and rivers, where it reacts with rocks and sand. It releases chemical sulfur from the rocks and sand, creating a river rich in sulfuric acid . Sulfuric acid is toxic to plants, fish, and other aquatic organisms. Sulfuric acid is also toxic to people, making rivers polluted by AMD dangerous sources of water for drinking and hygiene . Oil spills are another source of water pollution. In April 2010, the Deepwater Horizon oil rig exploded in the Gulf of Mexico, causing oil to gush from the ocean floor. In the following months, hundreds of millions of gallons of oil spewed into the gulf waters. The spill produced large plumes of oil under the sea and an oil slick on the surface as large as 24,000 square kilometers (9,100 square miles). The oil slick coated wetlands in the U.S. states of Louisiana and Mississippi, killing marsh plants and aquatic organisms such as crabs and fish. Birds, such as pelicans , became coated in oil and were unable to fly or access food. More than two million animals died as a result of the Deepwater Horizon oil spill. Buried chemical waste can also pollute water supplies. For many years, people disposed of chemical wastes carelessly, not realizing its dangers. In the 1970s, people living in the Love Canal area in Niagara Falls, New York, suffered from extremely high rates of cancer and birth defects . It was discovered that a chemical waste dump had poisoned the area’s water. In 1978, 800 families living in Love Canal had to a bandon their homes. If not disposed of properly, radioactive waste from nuclear power plants can escape into the environment. Radioactive waste can harm living things and pollute the water. Sewage that has not been properly treated is a common source of water pollution. Many cities around the world have poor sewage systems and sewage treatment plants. Delhi, the capital of India, is home to more than 21 million people. More than half the sewage and other waste produced in the city are dumped into the Yamuna River. This pollution makes the river dangerous to use as a source of water for drinking or hygiene. It also reduces the river’s fishery , resulting in less food for the local community. A major source of water pollution is fertilizer used in agriculture . Fertilizer is material added to soil to make plants grow larger and faster. Fertilizers usually contain large amounts of the elements nitrogen and phosphorus , which help plants grow. Rainwater washes fertilizer into streams and lakes. There, the nitrogen and phosphorus cause cyanobacteria to form harmful algal blooms. Rain washes other pollutants into streams and lakes. It picks up animal waste from cattle ranches. Cars drip oil onto the street, and rain carries it into storm drains , which lead to waterways such as rivers and seas. Rain sometimes washes chemical pesticides off of plants and into streams. Pesticides can also seep into groundwater , the water beneath the surface of the Earth. Heat can pollute water. Power plants, for example, produce a huge amount of heat. Power plants are often located on rivers so they can use the water as a coolant . Cool water circulates through the plant, absorbing heat. The heated water is then returned to the river. Aquatic creatures are sensitive to changes in temperature. Some fish, for example, can only live in cold water. Warmer river temperatures prevent fish eggs from hatching. Warmer river water also contributes to harmful algal blooms. Another type of water pollution is simple garbage. The Citarum River in Indonesia, for example, has so much garbage floating in it that you cannot see the water. Floating trash makes the river difficult to fish in. Aquatic animals such as fish and turtles mistake trash, such as plastic bags, for food. Plastic bags and twine can kill many ocean creatures. Chemical pollutants in trash can also pollute the water, making it toxic for fish and people who use the river as a source of drinking water. The fish that are caught in a polluted river often have high levels of chemical toxins in their flesh. People absorb these toxins as they eat the fish. Garbage also fouls the ocean. Many plastic bottles and other pieces of trash are thrown overboard from boats. The wind blows trash out to sea. Ocean currents carry plastics and other floating trash to certain places on the globe, where it cannot escape. The largest of these areas, called the Great Pacific Garbage Patch, is in a remote part of the Pacific Ocean. According to some estimates, this garbage patch is the size of Texas. The trash is a threat to fish and seabirds, which mistake the plastic for food. Many of the plastics are covered with chemical pollutants. Land Pollution Many of the same pollutants that foul the water also harm the land. Mining sometimes leaves the soil contaminated with dangerous chemicals. Pesticides and fertilizers from agricultural fields are blown by the wind. They can harm plants, animals, and sometimes people. Some fruits and vegetables absorb the pesticides that help them grow. When people consume the fruits and vegetables, the pesticides enter their bodies. Some pesticides can cause cancer and other diseases. A pesticide called DDT (dichlorodiphenyltrichloroethane) was once commonly used to kill insects, especially mosquitoes. In many parts of the world, mosquitoes carry a disease called malaria , which kills a million people every year. Swiss chemist Paul Hermann Muller was awarded the Nobel Prize for his understanding of how DDT can control insects and other pests. DDT is responsible for reducing malaria in places such as Taiwan and Sri Lanka. In 1962, American biologist Rachel Carson wrote a book called Silent Spring , which discussed the dangers of DDT. She argued that it could contribute to cancer in humans. She also explained how it was destroying bird eggs, which caused the number of bald eagles, brown pelicans, and ospreys to drop. In 1972, the United States banned the use of DDT. Many other countries also banned it. But DDT didn’t disappear entirely. Today, many governments support the use of DDT because it remains the most effective way to combat malaria. Trash is another form of land pollution. Around the world, paper, cans, glass jars, plastic products, and junked cars and appliances mar the landscape. Litter makes it difficult for plants and other producers in the food web to create nutrients . Animals can die if they mistakenly eat plastic. Garbage often contains dangerous pollutants such as oils, chemicals, and ink. These pollutants can leech into the soil and harm plants, animals, and people. Inefficient garbage collection systems contribute to land pollution. Often, the garbage is picked up and brought to a dump, or landfill . Garbage is buried in landfills. Sometimes, communities produce so much garbage that their landfills are filling up. They are running out of places to dump their trash. A massive landfill near Quezon City, Philippines, was the site of a land pollution tragedy in 2000. Hundreds of people lived on the slopes of the Quezon City landfill. These people made their living from recycling and selling items found in the landfill. However, the landfill was not secure. Heavy rains caused a trash landslide, killing 218 people. Sometimes, landfills are not completely sealed off from the land around them. Pollutants from the landfill leak into the earth in which they are buried. Plants that grow in the earth may be contaminated, and the herbivores that eat the plants also become contaminated. So do the predators that consume the herbivores. This process, where a chemical builds up in each level of the food web, is called bioaccumulation . Pollutants leaked from landfills also leak into local groundwater supplies. There, the aquatic food web (from microscopic algae to fish to predators such as sharks or eagles) can suffer from bioaccumulation of toxic chemicals. Some communities do not have adequate garbage collection systems, and trash lines the side of roads. In other places, garbage washes up on beaches. Kamilo Beach, in the U.S. state of Hawai'i, is littered with plastic bags and bottles carried in by the tide . The trash is dangerous to ocean life and reduces economic activity in the area. Tourism is Hawai'i’s largest industry . Polluted beaches discourage tourists from investing in the area’s hotels, restaurants, and recreational activities. Some cities incinerate , or burn, their garbage. Incinerating trash gets rid of it, but it can release dangerous heavy metals and chemicals into the air. So while trash incinerators can help with the problem of land pollution, they sometimes add to the problem of air pollution. Reducing Pollution Around the world, people and governments are making efforts to combat pollution. Recycling, for instance, is becoming more common. In recycling, trash is processed so its useful materials can be used again. Glass, aluminum cans, and many types of plastic can be melted and reused . Paper can be broken down and turned into new paper. Recycling reduces the amount of garbage that ends up in landfills, incinerators, and waterways. Austria and Switzerland have the highest recycling rates. These nations recycle between 50 and 60 percent of their garbage. The United States recycles about 30 percent of its garbage. Governments can combat pollution by passing laws that limit the amount and types of chemicals factories and agribusinesses are allowed to use. The smoke from coal-burning power plants can be filtered. People and businesses that illegally dump pollutants into the land, water, and air can be fined for millions of dollars. Some government programs, such as the Superfund program in the United States, can force polluters to clean up the sites they polluted. International agreements can also reduce pollution. The Kyoto Protocol , a United Nations agreement to limit the emission of greenhouse gases, has been signed by 191 countries. The United States, the world’s second-largest producer of greenhouse gases, did not sign the agreement. Other countries, such as China, the world’s largest producer of greenhouse gases, have not met their goals. Still, many gains have been made. In 1969, the Cuyahoga River, in the U.S. state of Ohio, was so clogged with oil and trash that it caught on fire. The fire helped spur the Clean Water Act of 1972. This law limited what pollutants could be released into water and set standards for how clean water should be. Today, the Cuyahoga River is much cleaner. Fish have returned to regions of the river where they once could not survive. But even as some rivers are becoming cleaner, others are becoming more polluted. As countries around the world become wealthier, some forms of pollution increase. Countries with growing economies usually need more power plants, which produce more pollutants. Reducing pollution requires environmental, political, and economic leadership. Developed nations must work to reduce and recycle their materials, while developing nations must work to strengthen their economies without destroying the environment. Developed and developing countries must work together toward the common goal of protecting the environment for future use.

How Long Does It Last? Different materials decompose at different rates. How long does it take for these common types of trash to break down?

• Paper: 2-4 weeks
• Orange peel: 6 months
• Milk carton: 5 years
• Plastic bag: 15 years
• Tin can: 100 years
• Plastic bottle: 450 years
• Glass bottle: 500 years
• Styrofoam: Never

Indoor Air Pollution The air inside your house can be polluted. Air and carpet cleaners, insect sprays, and cigarettes are all sources of indoor air pollution.

Light Pollution Light pollution is the excess amount of light in the night sky. Light pollution, also called photopollution, is almost always found in urban areas. Light pollution can disrupt ecosystems by confusing the distinction between night and day. Nocturnal animals, those that are active at night, may venture out during the day, while diurnal animals, which are active during daylight hours, may remain active well into the night. Feeding and sleep patterns may be confused. Light pollution also indicates an excess use of energy. The dark-sky movement is a campaign by people to reduce light pollution. This would reduce energy use, allow ecosystems to function more normally, and allow scientists and stargazers to observe the atmosphere.

Noise Pollution Noise pollution is the constant presence of loud, disruptive noises in an area. Usually, noise pollution is caused by construction or nearby transportation facilities, such as airports. Noise pollution is unpleasant, and can be dangerous. Some songbirds, such as robins, are unable to communicate or find food in the presence of heavy noise pollution. The sound waves produced by some noise pollutants can disrupt the sonar used by marine animals to communicate or locate food.

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Related Resources

• Open access
• Published: 08 March 2016

Challenges and Opportunities for Urban Environmental Health and Sustainability: the HEALTHY-POLIS initiative

• Sotiris Vardoulakis 1 , 3 ,
• Keith Dear 2 &
• Paul Wilkinson 3  

Environmental Health volume  15 , Article number:  S30 ( 2016 ) Cite this article

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Cities around the world face many environmental health challenges including contamination of air, water and soil, traffic congestion and noise, and poor housing conditions exacerbated by unsustainable urban development and climate change. Integrated assessment of these risks offers opportunities for holistic, low carbon solutions in the urban environment that can bring multiple benefits for public health. The Healthy-Polis consortium aims to protect and promote urban health through multi-disciplinary, policy-relevant research on urban environmental health and sustainability. We are doing this by promoting improved methods of health risk assessment, facilitating international collaboration, contributing to the training of research scientists and students, and engaging with key stakeholders in government, local authorities, international organisations, industry and academia. A major focus of the consortium is to promote and support international research projects coordinated between two or more countries. The disciplinary areas represented in the consortium are many and varied, including environmental epidemiology, modelling and exposure assessment, system dynamics, health impact assessment, multi-criteria decision analysis, and other quantitative and qualitative approaches. This Healthy-Polis special issue presents a range of case studies and reviews that illustrate the need for a systems-based understanding of the urban environment.

Rapid urbanization, combined with rapid improvement in standards of living is stretching natural resources and threatening environmental quality in many countries. Population density has reached unprecedented levels in most parts of the high, medium and low income world. The urban population in 2014 was 54 % of the total global population, up from 30 % in 1950, and is projected to account for around 66 % of the global population by 2050 [ 1 ]. Urban areas are facing a range of environmental health challenges including contamination of air, water and soil. Sprawling urban areas contribute to traffic congestion, with associated air pollution, noise and long commuting times affecting public health and productivity across the world.

In addition, climate change is likely to aggravate certain urban health risks and inequalities by increasing the frequency and severity of extreme weather events (heatwaves, storms and floods), potentially contributing to air pollution episodes (ground-level ozone and pollen) and disturbing urban ecology [ 2 ], [ 3 ]. The urban heat island effect (i.e. the difference in temperatures between a city centre and the surrounding countryside) also exacerbates heat stress in built up areas [ 4 ]. This has knock-on effects on the indoor environment, energy demand (for ventilation and cooling) and public health [ 5 ], [ 6 ].

However, there is also an opportunity here: climate change mitigation and adaptation measures can deliver a range of health benefits. These health benefits are likely to result from “low carbon” policies aimed at lowering greenhouse gas emissions by improving energy efficiency in buildings (enhancing thermal comfort for occupants) [ 5 ], reducing dependency on private car use (improving physical activity levels and local air quality) [ 7 ], increasing renewable energy generation (improving ambient air quality) [ 8 ], and reducing meat and dairy consumption (reducing saturated fat intake) [ 9 ]. Accounting for the health co-benefits of climate change mitigation strengthens the case for reductions in greenhouse gas emissions from many sectors. However, attention should also be paid to the unintended harmful effects of certain carbon reduction policies. For example, home energy efficiency measures have the potential to worsen indoor air quality if steps are not taken to maintain good ventilation [ 10 ]; and the promotion of active travel has the potential to increase road injury risks without separation of cyclists and pedestrians from other road traffic [ 7 ].

Cities are complex systems. Research to elucidate pathways to better health and wellbeing demands systems-based, interdisciplinary methods involving epidemiologists, toxicologists, urban planners, environmental scientists, mathematical modellers, engineers, IT experts, social scientists, public health researchers and health care professionals. Importantly, local communities need to be involved in research projects aiming to inform local policies from an early stage. This can be achieved through genuine stakeholder engagement [ 11 ], citizen science and knowledge co-generation approaches [ 12 ], which raise awareness, provide valuable information and improve acceptability of interventions.

Methodological innovation in epidemiology, exposure assessment and risk analysis, and standardization of methods across countries, are needed to address complex environmental health challenges in the context of climate change and sustainable development. Relevant areas include the assessment and reduction of the health risks and impacts of weather extremes, air pollution, water contamination and other forms of environmental hazard, especially in the context of climate change, and evaluating mitigation and adaptation options [ 13 ]. These challenges highlight the need for integrated assessment methods that account for the complex interactions (including feedback loops) between climatic, environmental and behavioural factors, and the urban fabric [ 14 ]. This is particularly the case in global megacities where exposure to environmental stressors (such air pollution, congestion, heat and noise) can be substantially higher than in rural areas. Particular opportunities for influencing development pathways may arise in the multitude of rapidly developing cities in low and middle income countries. System dynamics approaches [ 15 ] and multi-criteria decision analysis methods [ 16 ] integrating quantitative and qualitative evidence can help characterise the likely overall impacts of policy options in urban environments.

This is the approach adopted by Healthy-Polis ( www.healthy-polis.org ), a new international consortium for urban environmental health and sustainability which aims to: (1) promote innovation and standardization in research methods (including exposure modelling, environmental epidemiology, risk analysis and integrated assessment methods), (2) facilitate international, multi-disciplinary research collaborations, (3) provide training and promote capacity building especially in rapidly urbanizing countries, and (4) evaluate and promote environmental interventions to improve public health in cities.

A particular emphasis of Healthy-Polis is on engendering and supporting a growing community of young researchers in the field of urban environmental health, climate change and sustainability, who will push the research agenda forward through global collaborations in the coming critical decades.

Methods and case studies

The disciplinary areas represented in Healthy-Polis are many and varied, including environmental epidemiology, modelling and exposure assessment, system dynamics, health impact assessment, multi-criteria decision analysis, and other quantitative and qualitative approaches. Key areas of interest (Fig.  1 ) were discussed at the 1 st Healthy-Polis workshop in Manchester, U.K. (6 March 2014).

Healthy-Polis. Key areas of scientific research and inter-linkages in the urban environment

In this special issue of Environmental Health, we present twelve contributions that address the aims of the Healthy-Polis consortium using methods from many disciplines. Perhaps the most familiar connection between climate change and health is the impact of extreme weather events such as heatwaves. A systematic review by Arbuthnott et al. [ 17 ] covers the important question of whether susceptibility to heat and cold has changed over time. It appears that various populations did become less susceptible to heat, although attribution to a specific cause is difficult. Heaviside et al. [ 18 ] consider the attribution of mortality to the Urban Heat Island effect during heatwaves, finding an appreciable contribution of this effect to the excess mortality experienced in the West Midlands region of England in the 2003 European heatwave. In regard to the co-benefits of climate change mitigation, Sabel et al. [ 19 ] report on the health benefits of several European and Chinese cities’ actual mitigation efforts, finding mixed results but with relatively modest health gains. The significant contribution of this study was in additionally considering climate change impacts on positive health outcomes, such as wellbeing.

We include a set of papers that address various aspects of disease in the urban environment. Asikainen et al. [ 20 ] focus on the calculation of the annual burden of disease caused by exposure to indoor air pollution in EU countries, and how best to ventilate with outdoor air, which may also be polluted. Considering various measures of urban form in 50 urban areas in England, Fecht et al. [ 21 ] intriguingly report higher rates of premature cardiovascular mortality in cities with higher densities of road junctions. Turning to infectious disease, Semenza et al. [ 22 ] present a predictive model of West Nile Virus infections based on ambient temperature and other environmental determinants. Higher rates are projected under climate change which has implications for the safety of the blood supply. Analysing the consequences of China’s massive ongoing migration and rapid urbanisation, Li et al. [ 23 ] show that action to protect and improve health in cities can be taken at multiple scales from national to individual.

Many of the Healthy-Polis papers address the broad area of urbanisation and planning. Macmillan et al. [ 24 ] report a project in which over 50 stakeholders collaboratively built causal diagrams to capture the complexities of housing, energy and wellbeing and developed criteria for assessing housing policy, while Nieuwenhuijsen [ 25 ] surveys new concepts and methods developed to address the complexity of urban environmental health in the wider context of urban and transport planning. Turning to specifics, Woods et al. [ 26 ] show how multi-criteria decision analysis can be used to prioritize environmental health hazards in a city. Salmond et al. [ 27 ] consider the ecosystem services and disservices provided by planting street trees as an urban planning tool, and argue that a holistic approach is necessary to ensure a net benefit. Finally, Rietveld et al. [ 28 ] argue for a systems approach to water and waste management in cities, illustrating their points with case studies from three continents.

Conclusions and vision

The range of risks and opportunities for urban environmental health explored in this special issue clearly demonstrates the complexity of the challenge cities are facing in the 21 st century in the context of climate, land use and demographic change. As the planet becomes increasingly urbanised, pressure on natural resources (air, water, soil), urban infrastructure (housing and transport) and health care systems increases, but so does our capacity to address risks though technological innovation, international co-operation, and participatory decision-making at city level. Solutions may involve advanced “smart” systems (e.g. controlling energy consumption, temperature and ventilation in houses) as well as more traditional approaches (e.g. urban greening, promoting walking and cycling) to improve health and wellbeing. Importantly, these solutions need to be assessed in a holistic way to maximise the benefits (“win-win”, e.g. reducing energy consumption and improving thermal comfort and air quality in buildings) and avoid unintended trade-offs (“win-lose”, e.g. planting tree species that are aesthetically appealing but require high energy input for maintenance). Methods such as multi-criteria decision analysis, participatory system dynamics modelling and quantitative health impacts assessment can help avoid pitfalls of the past and create healthier and more sustainable cities. Healthy-Polis is committed to capitalizing on these opportunities by supporting international collaboration, building research capacity, and promoting dialogue between researchers, policy-makers and local communities.

UN: World Urbanization Prospects: The 2014 Revision. United Nations, New York; 2015.

Vardoulakis S, Dear K, Hajat S, Heaviside C, Eggen B, McMichael AJ: Comparative assessment of the effects of climate change on heat and cold related mortality in the UK and Australia. Environ Health Perspect. 2014, 122: 1285-1292.

Google Scholar  

Heal MR, Heaviside C, Doherty RM, Vieno M, Stevenson DS, Vardoulakis S: Health burdens of surface ozone in the UK for a range of future scenarios. Environ Int. 2013, 61: 36-44. 10.1016/j.envint.2013.09.010.

Article   CAS   Google Scholar  

Heaviside C, Cai X-M, Vardoulakis S: The effects of horizontal advection on the urban heat island in Birmingham and the West Midlands, United Kingdom during a heatwave. Q J Roy Meteorol Soc. 2015, 141: 1429-1441. 10.1002/qj.2452.

Article   Google Scholar  

Wilkinson P, Smith KR, Davies M, Adair H, Armstrong BG, Barrett M, et al: Health and Climate Change 1 Public health benefits of strategies to reduce greenhouse-gas emissions: household energy. Lancet. 2009, 374 (9705): 1917-1929. 10.1016/S0140-6736(09)61713-X.

Vardoulakis S, Dimitroulopoulou S, Thornes JE, Lai K-M, Taylor J, Myers I, et al: Impact of climate change on the domestic indoor environment and associated health risks in the UK. Environ Int. 2015, 85: 299-313. 10.1016/j.envint.2015.09.010.

Woodcock J, Edwards P, Tonne C, Armstrong BG, Ashiru O, Banister D, et al: Health and Climate Change 2 Public health benefits of strategies to reduce greenhouse-gas emissions: urban land transport. Lancet. 2009, 374 (9705): 1930-1943. 10.1016/S0140-6736(09)61714-1.

Haines A, Haines A, McMichael AJ, Smith KR, Roberts I, Woodcock J, et al: Health and Climate Change 6 Public health benefits of strategies to reduce greenhouse-gas emissions: overview and implications for policy makers. Lancet. 2009, 374 (9707): 2104-2114. 10.1016/S0140-6736(09)61759-1.

Friel S, Dangour AD, Garnett T, Lock K, Chalabi Z, Roberts I, et al: Health and Climate Change 4 Public health benefits of strategies to reduce greenhouse-gas emissions: food and agriculture. Lancet. 2009, 374 (9706): 2016-2025. 10.1016/S0140-6736(09)61753-0.

Shrubsole C, Ridley I, Biddulph P, Milner J, Vardoulakis S, Ucci M, et al: Indoor PM 2.5 exposure in London's domestic stock: Modelling current and future exposures following energy efficient refurbishment. Atmos Environ. 2012, 62: 336-343. 10.1016/j.atmosenv.2012.08.047.

Keune H, Ludlow D, van den Hazel P, Randall S, Bartonova A: A healthy turn in urban climate change policies; European city workshop proposes health indicators as policy integrators. Environ Health. 2012, 11 (Suppl 1): S14-10.1186/1476-069X-11-S1-S14.

Buytaert W, Zulkafli Z, Grainger S, Acosta L, Bastiaensen J, De Bièvre B, et al. Citizen science in hydrology and water resources: opportunities for knowledge generation, ecosystem service management, and sustainable development. Frontiers Earth Sci. 2014;2.

Vardoulakis S, Heaviside C: Health Effects of Climate Change in the UK 2012 – Current evidence, recommendations and research gaps. Health Protection Agency, Centre for Radiation, Chemical and Environmental Hazards 2012: UK.

Rydin Y, Bleahu A, Davies M, Dávila JD, Friel S, De Grandis G, et al: Shaping cities for health: complexity and the planning of urban environments in the 21st century. Lancet. 2012, 379 (9831): 2079-2108. 10.1016/S0140-6736(12)60435-8.

Proust K, Newell B, Brown H, Capon A, Browne C, Burton A, et al: Human Health and Climate Change: Leverage Points for Adaptation in Urban Environments. Int J Environ Res Public Health. 2012, 9 (6): 2134-2158. 10.3390/ijerph9062134.

Vlachokostas C, Achillas C, Moussiopoulos N, Banias G: Multicriteria methodological approach to manage urban air pollution. Atmos Environ. 2011, 45 (25): 4160-4169. 10.1016/j.atmosenv.2011.05.020.

Arbuthnott K, Hajat S, Heaviside C, Vardoulakis S. Changes in population susceptibility to heat and cold over time: assessing adaptation to climate change. Environ Health. 2016;15(Suppl 1):xx.

Heaviside C, Vardoulakis S, Cai X-M: Attribution of mortality to the Urban Heat Island during heatwaves in the West Midlands, UK. Environ Health. 2016;15(Suppl 1):xx.

Sabel CE, Hiscock R, Asikainen A, Bi J, Depledge M, den Elshout S, et al. Public Health impacts of city policies to reduce climate change: findings from the URGENCHE EU-China project. Environ Health. 2016;15(Suppl 1):xx.

Asikainen A, Paolo Carrer P, Kephalopoulos S, de Oliveira Fernandes E, Pawel Wargocki P, Hänninen O. Reducing burden of disease from residential indoor air exposures in Europe (HEALTHVENT project). Environ Health. 2016;15(Suppl 1):xx.

Fecht D, Fortunato L, Morley D, Hansell A, Gulliver J. Associations between urban metrics and mortality rates in England. Environ Health. 2016;15(Suppl 1):xx.

Semenza JC, Tran A, Espinosa L, Sudre B, Domanovic D, Paz S. Climate change projections of West Nile Virus infections in Europe: Implications for blood safety practices. Environ Health. 2016;15(Suppl 1):xx.

Li X, Song J, Lin T, Dixon J, Zhang G, Ye H: Urbanization and health in China, thinking at the national, local and individual levels. Environ Health. 2016, 15 (Suppl 1): xx-

Macmillan A, Davies M, Shrubsole C, Luxford N, May N, Chiu LF, et al. Integrated decision-making about housing, energy and wellbeing: a qualitative system dynamics model. Environ Health. 2016;15(Suppl 1):xx.

Nieuwenhuijsen MJ: Urban planning, environmental exposures and health-new concepts, methods and tools to improve health in cities. Environ Health. 2016, 15 (Suppl 1): xx-

Woods M, Crabbe H, Close R, Studden M, Milojevic A, Leonardi G, et al: Decision support for risk prioritisation of environmental health hazards in a UK city. Environ Health. 2016, 15 (Suppl 1): xx-

Salmond JA, Tadaki M, Vardoulakis S, Arbuthnott K, Coutts A, Demuzere M, et al. Health and climate related ecosystem services provided by street trees in the urban environment. Environ Health. 2016;15(Suppl 1):xx.

Rietveld LC, Siri JG, Chakravarty I, Arsénio AM, Biswas R, Chatterjee A. Systems approaches for urban water management and health. Environ Health. 2016;15(Suppl 1):xx.

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Acknowledgements

We are grateful to the Healthy-Polis scientific advisory committee, and to all authors and reviewers who contributed to this special issue.

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This article has been published as part of Environmental Health Volume 15 Suppl 1, 2016: Healthy-Polis: Challenges and Opportunities for Urban Environmental Health and Sustainability. The full contents of the supplement can be found at http://www.ehjournal.net/supplements/15/S1 .

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Vardoulakis, S., Dear, K. & Wilkinson, P. Challenges and Opportunities for Urban Environmental Health and Sustainability: the HEALTHY-POLIS initiative. Environ Health 15 (Suppl 1), S30 (2016). https://doi.org/10.1186/s12940-016-0096-1

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Air Pollution: Everything You Need to Know

How smog, soot, greenhouse gases, and other top air pollutants are affecting the planet—and your health.

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What is air pollution?

What causes air pollution, effects of air pollution, air pollution in the united states, air pollution and environmental justice, controlling air pollution, how to help reduce air pollution, how to protect your health.

Air pollution  refers to the release of pollutants into the air—pollutants that are detrimental to human health and the planet as a whole. According to the  World Health Organization (WHO) , each year, indoor and outdoor air pollution is responsible for nearly seven million deaths around the globe. Ninety-nine percent of human beings currently breathe air that exceeds the WHO’s guideline limits for pollutants, with those living in low- and middle-income countries suffering the most. In the United States, the  Clean Air Act , established in 1970, authorizes the U.S. Environmental Protection Agency (EPA) to safeguard public health by regulating the emissions of these harmful air pollutants.

“Most air pollution comes from energy use and production,” says  John Walke , director of the Clean Air team at NRDC. Driving a car on gasoline, heating a home with oil, running a power plant on  fracked gas : In each case, a fossil fuel is burned and harmful chemicals and gases are released into the air.

“We’ve made progress over the last 50 years in improving air quality in the United States, thanks to the Clean Air Act. But climate change will make it harder in the future to meet pollution standards, which are designed to  protect health ,” says Walke.

Air pollution is now the world’s fourth-largest risk factor for early death. According to the 2020  State of Global Air  report —which summarizes the latest scientific understanding of air pollution around the world—4.5 million deaths were linked to outdoor air pollution exposures in 2019, and another 2.2 million deaths were caused by indoor air pollution. The world’s most populous countries, China and India, continue to bear the highest burdens of disease.

“Despite improvements in reducing global average mortality rates from air pollution, this report also serves as a sobering reminder that the climate crisis threatens to worsen air pollution problems significantly,” explains  Vijay Limaye , senior scientist in NRDC’s Science Office. Smog, for instance, is intensified by increased heat, forming when the weather is warmer and there’s more ultraviolet radiation. In addition, climate change increases the production of allergenic air pollutants, including mold (thanks to damp conditions caused by extreme weather and increased flooding) and pollen (due to a longer pollen season). “Climate change–fueled droughts and dry conditions are also setting the stage for dangerous wildfires,” adds Limaye. “ Wildfire smoke can linger for days and pollute the air with particulate matter hundreds of miles downwind.”

The effects of air pollution on the human body vary, depending on the type of pollutant, the length and level of exposure, and other factors, including a person’s individual health risks and the cumulative impacts of multiple pollutants or stressors.

Smog and soot

These are the two most prevalent types of air pollution. Smog (sometimes referred to as ground-level ozone) occurs when emissions from combusting fossil fuels react with sunlight. Soot—a type of  particulate matter —is made up of tiny particles of chemicals, soil, smoke, dust, or allergens that are carried in the air. The sources of smog and soot are similar. “Both come from cars and trucks, factories, power plants, incinerators, engines, generally anything that combusts fossil fuels such as coal, gasoline, or natural gas,” Walke says.

Smog can irritate the eyes and throat and also damage the lungs, especially those of children, senior citizens, and people who work or exercise outdoors. It’s even worse for people who have asthma or allergies; these extra pollutants can intensify their symptoms and trigger asthma attacks. The tiniest airborne particles in soot are especially dangerous because they can penetrate the lungs and bloodstream and worsen bronchitis, lead to heart attacks, and even hasten death. In  2020, a report from Harvard’s T.H. Chan School of Public Health showed that COVID-19 mortality rates were higher in areas with more particulate matter pollution than in areas with even slightly less, showing a correlation between the virus’s deadliness and long-term exposure to air pollution. 

These findings also illuminate an important  environmental justice issue . Because highways and polluting facilities have historically been sited in or next to low-income neighborhoods and communities of color, the negative effects of this pollution have been  disproportionately experienced by the people who live in these communities.

Hazardous air pollutants

A number of air pollutants pose severe health risks and can sometimes be fatal, even in small amounts. Almost 200 of them are regulated by law; some of the most common are mercury,  lead , dioxins, and benzene. “These are also most often emitted during gas or coal combustion, incineration, or—in the case of benzene—found in gasoline,” Walke says. Benzene, classified as a carcinogen by the EPA, can cause eye, skin, and lung irritation in the short term and blood disorders in the long term. Dioxins, more typically found in food but also present in small amounts in the air, is another carcinogen that can affect the liver in the short term and harm the immune, nervous, and endocrine systems, as well as reproductive functions.  Mercury  attacks the central nervous system. In large amounts, lead can damage children’s brains and kidneys, and even minimal exposure can affect children’s IQ and ability to learn.

Another category of toxic compounds, polycyclic aromatic hydrocarbons (PAHs), are by-products of traffic exhaust and wildfire smoke. In large amounts, they have been linked to eye and lung irritation, blood and liver issues, and even cancer.  In one study , the children of mothers exposed to PAHs during pregnancy showed slower brain-processing speeds and more pronounced symptoms of ADHD.

Greenhouse gases

While these climate pollutants don’t have the direct or immediate impacts on the human body associated with other air pollutants, like smog or hazardous chemicals, they are still harmful to our health. By trapping the earth’s heat in the atmosphere, greenhouse gases lead to warmer temperatures, which in turn lead to the hallmarks of climate change: rising sea levels, more extreme weather, heat-related deaths, and the increased transmission of infectious diseases. In 2021, carbon dioxide accounted for roughly 79 percent of the country’s total greenhouse gas emissions, and methane made up more than 11 percent. “Carbon dioxide comes from combusting fossil fuels, and methane comes from natural and industrial sources, including large amounts that are released during oil and gas drilling,” Walke says. “We emit far larger amounts of carbon dioxide, but methane is significantly more potent, so it’s also very destructive.” 

Another class of greenhouse gases,  hydrofluorocarbons (HFCs) , are thousands of times more powerful than carbon dioxide in their ability to trap heat. In October 2016, more than 140 countries signed the Kigali Agreement to reduce the use of these chemicals—which are found in air conditioners and refrigerators—and develop greener alternatives over time. (The United States officially signed onto the  Kigali Agreement in 2022.)

Pollen and mold

Mold and allergens from trees, weeds, and grass are also carried in the air, are exacerbated by climate change, and can be hazardous to health. Though they aren’t regulated, they can be considered a form of air pollution. “When homes, schools, or businesses get water damage, mold can grow and produce allergenic airborne pollutants,” says Kim Knowlton, professor of environmental health sciences at Columbia University and a former NRDC scientist. “ Mold exposure can precipitate asthma attacks  or an allergic response, and some molds can even produce toxins that would be dangerous for anyone to inhale.”

Pollen allergies are worsening  because of climate change . “Lab and field studies are showing that pollen-producing plants—especially ragweed—grow larger and produce more pollen when you increase the amount of carbon dioxide that they grow in,” Knowlton says. “Climate change also extends the pollen production season, and some studies are beginning to suggest that ragweed pollen itself might be becoming a more potent allergen.” If so, more people will suffer runny noses, fevers, itchy eyes, and other symptoms. “And for people with allergies and asthma, pollen peaks can precipitate asthma attacks, which are far more serious and can be life-threatening.”

More than one in three U.S. residents—120 million people—live in counties with unhealthy levels of air pollution, according to the  2023  State of the Air  report by the American Lung Association (ALA). Since the annual report was first published, in 2000, its findings have shown how the Clean Air Act has been able to reduce harmful emissions from transportation, power plants, and manufacturing.

Recent findings, however, reflect how climate change–fueled wildfires and extreme heat are adding to the challenges of protecting public health. The latest report—which focuses on ozone, year-round particle pollution, and short-term particle pollution—also finds that people of color are 61 percent more likely than white people to live in a county with a failing grade in at least one of those categories, and three times more likely to live in a county that fails in all three.

In rankings for each of the three pollution categories covered by the ALA report, California cities occupy the top three slots (i.e., were highest in pollution), despite progress that the Golden State has made in reducing air pollution emissions in the past half century. At the other end of the spectrum, these cities consistently rank among the country’s best for air quality: Burlington, Vermont; Honolulu; and Wilmington, North Carolina. 

No one wants to live next door to an incinerator, oil refinery, port, toxic waste dump, or other polluting site. Yet millions of people around the world do, and this puts them at a much higher risk for respiratory disease, cardiovascular disease, neurological damage, cancer, and death. In the United States, people of color are 1.5 times more likely than whites to live in areas with poor air quality, according to the ALA.

Historically, racist zoning policies and discriminatory lending practices known as  redlining  have combined to keep polluting industries and car-choked highways away from white neighborhoods and have turned communities of color—especially low-income and working-class communities of color—into sacrifice zones, where residents are forced to breathe dirty air and suffer the many health problems associated with it. In addition to the increased health risks that come from living in such places, the polluted air can economically harm residents in the form of missed workdays and higher medical costs.

Environmental racism isn't limited to cities and industrial areas. Outdoor laborers, including the estimated three million migrant and seasonal farmworkers in the United States, are among the most vulnerable to air pollution—and they’re also among the least equipped, politically, to pressure employers and lawmakers to affirm their right to breathe clean air.

Recently,  cumulative impact mapping , which uses data on environmental conditions and demographics, has been able to show how some communities are overburdened with layers of issues, like high levels of poverty, unemployment, and pollution. Tools like the  Environmental Justice Screening Method  and the EPA’s  EJScreen  provide evidence of what many environmental justice communities have been explaining for decades: that we need land use and public health reforms to ensure that vulnerable areas are not overburdened and that the people who need resources the most are receiving them.

In the United States, the  Clean Air Act  has been a crucial tool for reducing air pollution since its passage in 1970, although fossil fuel interests aided by industry-friendly lawmakers have frequently attempted to  weaken its many protections. Ensuring that this bedrock environmental law remains intact and properly enforced will always be key to maintaining and improving our air quality.

But the best, most effective way to control air pollution is to speed up our transition to cleaner fuels and industrial processes. By switching over to renewable energy sources (such as wind and solar power), maximizing fuel efficiency in our vehicles, and replacing more and more of our gasoline-powered cars and trucks with electric versions, we'll be limiting air pollution at its source while also curbing the global warming that heightens so many of its worst health impacts.

And what about the economic costs of controlling air pollution? According to a report on the Clean Air Act commissioned by NRDC, the annual  benefits of cleaner air  are up to 32 times greater than the cost of clean air regulations. Those benefits include up to 370,000 avoided premature deaths, 189,000 fewer hospital admissions for cardiac and respiratory illnesses, and net economic benefits of up to $3.8 trillion for the U.S. economy every year.

“The less gasoline we burn, the better we’re doing to reduce air pollution and the harmful effects of climate change,” Walke explains. “Make good choices about transportation. When you can, ride a bike, walk, or take public transportation. For driving, choose a car that gets better miles per gallon of gas or  buy an electric car .” You can also investigate your power provider options—you may be able to request that your electricity be supplied by wind or solar. Buying your food locally cuts down on the fossil fuels burned in trucking or flying food in from across the world. And most important: “Support leaders who push for clean air and water and responsible steps on climate change,” Walke says.

• “When you see in the news or hear on the weather report that pollution levels are high, it may be useful to limit the time when children go outside or you go for a jog,” Walke says. Generally, ozone levels tend to be lower in the morning.
• If you exercise outside, stay as far as you can from heavily trafficked roads. Then shower and wash your clothes to remove fine particles.
• The air may look clear, but that doesn’t mean it’s pollution free. Utilize tools like the EPA’s air pollution monitor,  AirNow , to get the latest conditions. If the air quality is bad, stay inside with the windows closed.
• If you live or work in an area that’s prone to wildfires,  stay away from the harmful smoke  as much as you’re able. Consider keeping a small stock of masks to wear when conditions are poor. The most ideal masks for smoke particles will be labelled “NIOSH” (which stands for National Institute for Occupational Safety and Health) and have either “N95” or “P100” printed on it.
• If you’re using an air conditioner while outdoor pollution conditions are bad, use the recirculating setting to limit the amount of polluted air that gets inside. 

This story was originally published on November 1, 2016, and has been updated with new information and links.

This NRDC.org story is available for online republication by news media outlets or nonprofits under these conditions: The writer(s) must be credited with a byline; you must note prominently that the story was originally published by NRDC.org and link to the original; the story cannot be edited (beyond simple things such as grammar); you can’t resell the story in any form or grant republishing rights to other outlets; you can’t republish our material wholesale or automatically—you need to select stories individually; you can’t republish the photos or graphics on our site without specific permission; you should drop us a note to let us know when you’ve used one of our stories.

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Recent Technologies for Disaster Management and Risk Reduction pp 319–362 Cite as

Urban and Environmental Hazards

• Kriti Varma 4 ,
• Vaishali Srivastava 4 ,
• Anjali Singhal 5 &
• Pawan Kumar Jha 4  
• First Online: 22 August 2021

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Part of the book series: Earth and Environmental Sciences Library ((EESL))

The ever-rising urbanization and economic aspirations of humans have led to the increased vulnerability of humans to future hazards. The prominent urban and environmental hazards that have emerged in the past few decades include pollution, floods, earthquakes, and the urban heat island effect. The potential risks in the future can be attributed to two factors, population rise and subsequent increase in the ‘built’ environment. It is quite natural that the increasing population would generate more waste, need more land for residential, industrial, healthcare, education, and other purposes. The rapid developmental and economic activities in the urban areas have aggravated environmental pollution through the discharge of untreated industrial waste, domestic and municipal effluents, and toxic industrial and vehicular emissions. Another most severe environmental hazard, in recent times, floods, is prevalent in the South and South-East Asian countries. The process of urbanization comprises of construction of roads and buildings, by removing vegetation and soil. Such constructions lead to the replacement of permeable soil with impermeable surfaces, causing decreased infiltration of water to the ground and increased runoff to the surface water bodies, aggravating the frequency and impact of the flood causing inundation of land and human settlements amongst others. Also, unplanned concrete construction activities in urban areas have exposed the urban population to significant seismic hazards worldwide. The urban towns, capital cities, and business centers have surpassed their carrying capacity, disturbing the seismic activity. The sudden release of accumulated tectonic energy, when it strikes densely populated urban centers causes an earthquake, rendering most of the urban inhabitants either dead or homeless, disconnected, and deprived of their basic needs. Another devastating hazard of the modern period is the ‘urban heat island effect’. Studies of urban climate suggest that significant difference prevails in the ambient air temperature of cities and their adjoining rural areas, giving rise to the urban heat island effect. This is mainly due to the emissions from industries and concrete infrastructure occupying the urban areas. This study deals with these urban environmental hazards taking into account their causes, impacts, frequency of occurrence together with mitigation and management policies/practices worldwide and in the Indian context, in an attempt to save life, property, and environment as well.

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• Urbanization
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Abdel-Shafy HI, Mansour MS (2018) Solid waste issue: sources, composition, disposal, recycling, and valorization. Egypt J of Petrol 27(4):1275–1290

Article   Google Scholar  

Abrol, Y., Sangwan, S., and Tiwari, M. 2002. Land Use--Historical Perspectives: Focus on Indo-Gangetic Plains. Allied Publishers.

Google Scholar  

Acharya S, Hori T (2019) Revisiting flood management process in Transboundary Koshi River in Nepal and India. DPRI Annu , 62(B):640–649

Adinna EN, Christian EI, Okolie AT (2009) Assessment of urban heat island and possible adaptations in Enugu urban using Landsat-ETM. J Geogr Reg Plan 2(2):30–36

Afroz R, Hassan MN, Ibrahim NA (2003) Review of air pollution and health impacts in Malaysia. Environ Res 92(2):71–77. https://doi.org/10.1016/S0013-9351(02)00059-2

Ahmad N, Pandey P (2020) Spatio-temporal distribution, ecological risk assessment, and multivariate analysis of heavy metals in Bathinda District, Punjab, India. Water Air Soil Pollut 231(8). https://doi.org/10.1007/s11270-020-04767-9

Akbari H (2003) Measured energy savings from the application of reflective roofs in two small non-residential buildings. Energy 28(9):953–967. https://doi.org/10.1016/S0360-5442(03)00032-X

Akbari H, Pomerantz M, Taha H (2001) Cool surfaces and shade trees to reduce energy use and improve air quality in urban areas. Sol Energy 70(3):295–310. https://doi.org/10.1016/S0038-092X(00)00089-X

Ali S, Cheema MJM, Bakhsh A, Khaliq T (2020) Near real-time flood forecasting in the transboundary Chenab river using global satellite mapping of precipitation. Pakistan J Agric Sci 57(5):1327–1335. https://doi.org/10.21162/PAKJAS/20.111

Allen SK, Rastner P, Arora M, Huggel C, Stoffel M (2016) Lake outburst and debris flow disaster at Kedarnath, June 2013: hydrometeorological triggering and topographic predisposition. Landslides 13(6):1479–1491. https://doi.org/10.1007/s10346-015-0584-3

Al-Mulali U, Ozturk I, Lean HH (2015) The influence of economic growth, urbanization, trade openness, financial development, and renewable energy on pollution in Europe. Nat Hazards 79(1):621–644. https://doi.org/10.1007/s11069-015-1865-9

Anderson JC, Park BJ, Palace VP (2016) Microplastics in aquatic environments: Implications for Canadian ecosystems. Environ Pollut 218:269–280

Anjum M, Miandad R, Waqas M, Ahmad I, Omar Z, Alafif A, Aburiazaiza AS, Barakat MAE, Akhtar T (2016) Solid waste management in Saudi Arabia: a review. J Appl Agric Biotechnol

Arun G, Sharma SK, Tirkey G, Lohani AK (2020) Integrated flood assessment studies using real time satellite precipitation data and flood inundation mapping in Assam-a novel approach. In: Proceeding of national conference on emerging trends in civil engineering during 26th, vol 27

Balakrishnan K, Dey S, Gupta T, Dhaliwal RS (2019) The impact of air pollution on deaths, disease burden, and life expectancy across the states of India: the Global Burden of Disease Study 2017. Lancet Planet Health. https://doi.org/10.1016/S2542-5196(18)30261-4

Bandyopadhyay et al (2020) Introduction: a harmonized approach towards water management in South Asia. In: water management in South Asia, ed. Sumana Bandyopadhyay et al (Cham, Switzerland: Springer Nature, 2020), 175–202

Bass B, Krayenhoff ES, Martilli A, Stull RB, AH (2003) The impact of green roofs on urban heat island effect. Green Rooftops Sustain Communities 292–304

Bhandarkar S, Lecturer S (2013) Vehicular pollution, their effect on human heatlh and mitigation measures. Veh Eng 1(2):33–40

Bhatt CM, Rao GS, Diwakar PG, Dadhwal VK (2017) Development of flood inundation extent libraries over a range of potential flood levels: a practical framework for quick flood response. Geomatics, Nat Hazards Risk 8(2):384–401. https://doi.org/10.1080/19475705.2016.1220025

Bhattacharjee K, Behera B (2017) Forest cover change and flood hazards in India. Land Use Policy 67:436–448. https://doi.org/10.1016/j.landusepol.2017.06.013

Bianchi S, Ciurlanti J, Pampanin S (2020) Comparison of traditional vs low-damage structural and non-structural building systems through a cost/performance-based evaluation. Earthq Spectra. https://doi.org/10.1177/8755293020952445

Bishop KC, Ketcham JD, Kuminoff NV (2018) Hazed and confused: the effect of air pollution on dementia. NBER Work Pap Ser 24970

Bohnenstengel SI, Evans S, Clark PA, Belcher SE (2011) Simulations of the London urban heat island. Q J R Meteorol Soc 137(659):1625–1640. https://doi.org/10.1002/qj.855

Bonan GB (2000) The microclimates of a suburban Colorado (USA) landscape and implications for planning and design. Landsc Urban Plan 49(3–4):97–114. https://doi.org/10.1016/S0169-2046(00)00071-2

Brack CL (2002) Pollution mitigation and carbon sequestration by an urban forest. Environ Pollut 116(SUPPL. 1). https://doi.org/10.1016/S0269-7491(01)00251-2

Brombal D, Moriggi A, Marcomini A (2017) Evaluating public participation in Chinese EIA. An integrated Public Participation Index and its application to the case of the New Beijing Airport. Environ Impact Assess Rev 62:49–60. https://doi.org/10.1016/j.eiar.2016.07.001

Burney J, Ramanathan V (2014) Recent climate and air pollution impacts on Indian agriculture. Proc Natl Acad Sci USA 111(46):16319–16324. https://doi.org/10.1073/pnas.1317275111

Burns DA, Aherne J, Gay DA, Lehmann CMB (2016) Acid rain and its environmental effects: recent scientific advances. Atmos Environ

Bush MJ (2017) Climate change adaptation in small Island developing states. Wiley Blackwell

Cachada A, Rocha-Santos TAP, Duarte AC (2017) Soil and pollution: an introduction to the main issues. In: Soil Poll: From Monit Remediat, pp 1–28

Chakraborty P (2017) Oyster reef restoration in controlling coastal pollution around India: a viewpoint. Mar Pollut Bull 115(1–2):190–193. https://doi.org/10.1016/j.marpolbul.2016.11.059

Chen J (2007) Rapid urbanization in China: a real challenge to soil protection and food security. CATENA 69(1):1–15. https://doi.org/10.1016/j.catena.2006.04.019

Chen F, Yang X, Zhu W (2014) WRF simulations of urban heat island under hot-weather synoptic conditions: the case study of Hangzhou City, China. Atmos Res 138:364–377. https://doi.org/10.1016/j.atmosres.2013.12.005

Choudhury M, Sajal V, Saha P (2016) Effects of earthquake on the surrounding environment: an overview. In: Proceedings of international conference on recent advances in mechanics and materials (ICRAMM-2016), p RR03

Chow WTL, Roth M (2006) Temporal dynamics of the urban heat island of Singapore. Int J Climatol 26(15):2243–2260. https://doi.org/10.1002/joc.1364

Conley DJ, Paerl HW, Howarth RW, Boesch DF, Seitzinger SP, Havens KE, Lancelot C, Likens GE (2009) Ecology—Controlling eutrophication: Nitrogen and phosphorus. Sci (80-. ) 323:1014–1015

Coutts AM, Daly E, Beringer J, Tapper NJ (2013) Assessing practical measures to reduce urban heat: green and cool roofs. Build Environ 70:266–276. https://doi.org/10.1016/j.buildenv.2013.08.021

Currell MJ, Han D (2017) The global drain: Why China’s water pollution problems should matter to the rest of the world. Environ 59(1):16–29. https://doi.org/10.1080/00139157.2017.1252605

CWC (Central Water Commission) (2013) Water and related statistics. Water resources information system directorate. Information system organization, Water planning and project wing, Central Water Commission, New Delhi

Dahshan H, Megahed AM, Abd-Elall AMM, Abd-El-Kader MAG, Nabawy E, Elbana MH (2016) Monitoring of pesticides water pollution-The Egyptian River Nile. J Environ Heal Sci Eng 14(1):1–9. https://doi.org/10.1186/s40201-016-0259-6

Das S (2019) Geospatial mapping of flood susceptibility and hydro-geomorphic response to the floods in Ulhas basin, India. Remote Sens Appl Soc Environ 14:60–74. https://doi.org/10.1016/j.rsase.2019.02.006

Debbage N (2019) Multiscalar spatial analysis of urban flood risk and environmental justice in the Charlanta megaregion, USA. Anthropocene 28:100226

Deka A, Gulati V, Barua A (2019) Transboundary water sharing issues in international and national perspectives. Water Res Dev Manage 99–114

Delang CO (2018) Causes and distribution of soil pollution in China. Environ Socio-Economic Stud 5(4):1–17. https://doi.org/10.1515/environ-2017-0016

DesRoches R, Comerio M, Eberhard M, Mooney W, Rix GJ (2011) Overview of the 2010 Haiti Earthquake. Earthq Spectra , 27(1_suppl1):1–21. https://doi.org/10.1193/1.3630129

Dhiman R, VishnuRadhan R, Eldho TI, Inamdar A (2019) Flood risk and adaptation in Indian coastal cities: recent scenarios. Appl Water Sci 9(1). https://doi.org/10.1007/s13201-018-0881-9

Díaz J, Ortiz C, Falcón I, Salvador C, Linares C (2018) Short-term effect of tropospheric ozone on daily mortality in Spain. Atmos Environ 187:107–116. https://doi.org/10.1016/j.atmosenv.2018.05.059

Dickinson RE (1983) Land surface processes and climate—surface albedos and energy balance. Adv Geophys 5(C):305–353. https://doi.org/10.1016/S0065-2687(08)60176-4

Dobbs C, Escobedo FJ, Zipperer WC (2011) A framework for developing urban forest ecosystem services and goods indicators. Landsc Urban Plan 99(3–4):196–206. https://doi.org/10.1016/j.landurbplan.2010.11.004

Du E, Dong D, Zeng X, Sun Z, Jiang X, de Vries W (2017) Direct effect of acid rain on leaf chlorophyll content of terrestrial plants in China. Sci Total Environ 605–606:764–769. https://doi.org/10.1016/j.scitotenv.2017.06.044

Duan Q, Lee J, Liu Y, Chen H, Hu H (2016) Distribution of heavy metal pollution in surface soil samples in China: a graphical review. Bull Environ Contam Toxicol 97:303–309

E.P.A. (2008) Reducing urban heat islands. Compend Strateg Heat Isl Reduct Act 1–23

Emberson LD, Ashmore MR, Murray F, Kuylenstierna JCI, Percy KE, Izuta T, Zheng Y, Shimizu H, Sheu BH, Liu CP, Agrawal M, Wahid A, Abdel-Latif NM, Van Tienhoven M, De Bauer LI, Domingos M (2001) Impacts of air pollutants on vegetation in developing countries. Water Air Soil Pollut 130(1–4):107–118. https://doi.org/10.1023/A:1012251503358

Escobedo FJ, Kroeger T, Wagner JE (2011) Urban forests and pollution mitigation: analyzing ecosystem services and disservices. Environ Pollut 159:2078–2087

Fahy B, Brenneman E, Chang H, Shandas V (2019) Spatial analysis of urban flooding and extreme heat hazard potential in Portland, OR. Int J Disaster Risk Red 39:101117

García-Soriano D, Quesada-Román A, Zamorano-Orozco JJ (2020) Geomorphological hazards susceptibility in high-density urban areas: a case study of Mexico City. J South Am Earth Sci 102667

Garg A, Gupta NC (2020) The great smog month and spatial and monthly variation in air quality in ambient air in Delhi, India. J Health Pollut 10(27). https://doi.org/10.5696/2156-9614-10.27.200910 .

Garricka D, Krantzbergb G, Jetooc S (2016) Building transboundary water governance capacity for non-point pollution: a comparison of Australia and North America. Int J Water 1:111–132

Gaur S (2018) An updated review on quantitative and qualitative analysis of water pollution in west flowing Tapi River of Gujarat, India, 525–547

Ghosh N, Bandyopadhyay J, Modak S (2019) China-India data sharing for early flood warning in the Brahmaputra: a Critique. ORF Issue Br

Glibert PM, Seitzinger S, Heil CA, Burkholder JM, Parrow MW, Codispoti LA, Kelly V (2005) Eutrophication. Oceanogr 18(2):198

Goel PK (2006) Water pollution: causes, effects and control. New Age Int 418:9–11

Gotham KF, Campanella R, Lauve-Moon K, Powers B (2018) Hazard experience, geophysical vulnerability, and flood risk perceptions in a postdisaster city, the case of new orleans. Risk Anal 38(2):345–356. https://doi.org/10.1111/risa.12830

Grady Dixon P, Mote TL (2003) Patterns and causes of Atlanta’s urban heat island-initiated precipitation. J Appl Meteorol 42(9):1273–1284. https://doi.org/10.1175/1520-0450(2003)042%3c1273:PACOAU%3e2.0.CO;2

Grainger C, Schreiber A (2019) Discrimination in ambient air pollution monitoring? AEA Pap Proc 109:277–282. https://doi.org/10.1257/pandp.20191063

Gregoire C, Elsaesser D, Huguenot D, Lange J, Lebeau T, Merli A, Mose R, Passeport E, Payraudeau S, Schütz T, Schulz R, Tapia-Padilla G, Tournebize J, Trevisan M, Wanko A (2009) Mitigation of agricultural nonpoint-source pesticide pollution in artificial wetland ecosystems. Environ Chem Lett 7(3):205–231. https://doi.org/10.1007/s10311-008-0167-9

Grimm NB, Foster D, Groffman P, Grove JM, Hopkinson CS, Nadelhoffer KJ, Pataki DE, Peters DPC (2008) The changing landscape: ecosystem responses to urbanization and pollution across climatic and societal gradients. Front Ecol Environ 6:264–272

Gupta HK (2020) Recent earthquakes in Delhi and developing an earthquake resilient society. J Geol Soc India 96:107–110

Hamilton JP, Halvorson SJ (2007) The 2005 kashmir earthquake. Mt Res Dev 27(4):296–301

Harrison S, Kargel JS, Huggel C, Reynolds J, Shugar DH, Betts RA, Emmer A, Glasser N, Haritashya UK, Klimeš J, Reinhardt L, Schaub Y, Wiltshire A, Regmi D, Vilímek V (2018) Climate change and the global pattern of moraine-dammed glacial lake outburst floods. Cryosphere 12(4):1195–1209. https://doi.org/10.5194/tc-12-1195-2018

Hart MA, Sailor DJ (2009) Quantifying the influence of land-use and surface characteristics on spatial variability in the urban heat island. Theor Appl Climatol 95(3–4):397–406. https://doi.org/10.1007/s00704-008-0017-5

Hasan MK, Shahriar A, Jim KU (2019) Water pollution in Bangladesh and its impact on public health. Heliyon 5(8):e02145. https://doi.org/10.1016/j.heliyon.2019.e02145

Hassid S, Santamouris M, Papanikolaou N, Linardi A, Klitsikas N, Georgakis C, Assimakopoulos DN (2000) Effect of the Athens heat island on air conditioning load. Energy Build 32(2):131–141. https://doi.org/10.1016/S0378-7788(99)00045-6

Hayes F, Sharps K, Harmens H, Roberts I, Mills G (2020a) Tropospheric ozone pollution reduces the yield of African crops. J Agron Crop Sci 206(2):214–228. https://doi.org/10.1111/jac.12376

Hayes GP, Smoczyk GM, Villaseñor AH, Furlong KP, Benz HM (2020b) Seismicity of the earth 1900–2018: U.S. geological survey scientific investigations map 3446, scale 1:22,500,000. https://doi.org/10.3133/sim3446

Hu Y, Liu X, Bai J, Shih K, Zeng EY, Cheng H (2013) Assessing heavy metal pollution in the surface soils of a region that had undergone three decades of intense industrialization and urbanization. Environ Sci Pollut Res 20(9):6150–6159. https://doi.org/10.1007/s11356-013-1668-z

İmamoglu A, Dengiz O (2019) Evaluation of soil quality index to assess the influence of soil degradation and desertification process in sub-arid terrestrial ecosystem. Rend Lincei 30(4):723–734. https://doi.org/10.1007/s12210-019-00833-5

Imhoff ML, Zhang P, Wolfe RE, Bounoua L (2010) Remote sensing of the urban heat island effect across biomes in the continental USA. Remote Sens Environ 114(3):504–513. https://doi.org/10.1016/j.rse.2009.10.008

IPCC (Intergovernmental Panel on Climate Change), Fourth Assessment Report (2007) Retrieved from https://www.ipcc.ch/site/assets/uploads/2018/02/ar4_syr_full_report.pdf . Accessed on 12 Dec 2020

Islam MS, Tanaka M (2004) Impacts of pollution on coastal and marine ecosystems including coastal and marine fisheries and approach for management: a review and synthesis. Mar Pollut Bull 48:624–649

Izah SC, Angaye TCN (2016) Heavy metal concentration in fishes from surface water in Nigeria: potential sources of pollutants and mitigation measures. Sky J Biochem Res 5(4):31–047

Jafari A, Ghaderpoori M, Kamarehi B, Abdipour H (2019) Soil pollution evaluation and health risk assessment of heavy metals around Douroud cement factory, Iran. Environ Earth Sci 78(8). https://doi.org/10.1007/s12665-019-8220-5

Jain SK (1998) Indian earthquakes : an overview. Indian Concr J 72:555–561

Jain SK, Pathak S (2012) Intensity based casualty models: case study. In: 15th world conference on earthquake engineering, vol 1 of 38. Lisbon, Portugal. ISBN: 978-1-63439-651-6

Jonkman SN (2005) Global perspectives on loss of human life caused by floods. Nat Hazards 34(2):151–175. https://doi.org/10.1007/s11069-004-8891-3

Kardinal Jusuf S, Wong NH, Hagen E, Anggoro R, Hong Y (2007) The influence of land use on the urban heat island in Singapore. Habitat Int 31(2):232–242. https://doi.org/10.1016/j.habitatint.2007.02.006

Karn SK, Harada H (2001) Surface water pollution in three urban territories of Nepal, India, and Bangladesh. Environ Manage 28(4):483–496. https://doi.org/10.1007/s002670010238

Karthe D, Abdullaev I, Boldgiv B, Borchardt D, Chalov S, Jarsjö J, Li L, Nittrouer JA (2017) Water in central Asia: an integrated assessment for science-based management. Environ Earth Sci 76

Khan I, Umar R (2019) Environmental risk assessment of coal fly ash on soil and groundwater quality, Aligarh, India. Groundw Sustain Dev 8:346–357. https://doi.org/10.1016/j.gsd.2018.12.002

Khan MM, Zaman K, Irfan D, Awan U, Ali G, Kyophilavong P, Shahbaz M, Naseem I (2016) Triangular relationship among energy consumption, air pollution and water resources in Pakistan. J Clean Prod 112:1375–1385. https://doi.org/10.1016/j.jclepro.2015.01.094

Kidd K, Clayden M, Jardine T (2011) Bioaccumulation and biomagnification of mercury through food webs. Environ Chem Toxicol Mercury 453–499

Kikegawa Y, Genchi Y, Yoshikado H, Kondo H (2003) Development of a numerical simulation system toward comprehensive assessments of urban warming countermeasures including their impacts upon the urban buildings’ energy-demands. Appl Energy 76(4):449–466. https://doi.org/10.1016/S0306-2619(03)00009-6

Kim K, Han D, Kim D, Wang W, Jung J, Kim J, Kim HS (2019) Combination of structural measures for flood prevention in Anyangcheon river basin, South Korea. Water (Switzerland) , 11(11). https://doi.org/10.3390/w11112268

Kolokotroni M, Giannitsaris I, Watkins R (2006) The effect of the London urban heat island on building summer cooling demand and night ventilation strategies. Sol Energy 80(4):383–392. https://doi.org/10.1016/j.solener.2005.03.010

Kolokotroni M, Zhang Y, Watkins R (2007) The London Heat Island and building cooling design. Sol Energy 81(1):102–110. https://doi.org/10.1016/j.solener.2006.06.005

Kotharkar R, Bagade A (2018) Evaluating urban heat island in the critical local climate zones of an Indian city. Landsc Urban Plan 169:92–104. https://doi.org/10.1016/j.landurbplan.2017.08.009

Kowalska J, Mazurek R, Gąsiorek M, Setlak M, Zaleski T, Waroszewski J (2016) Soil pollution indices conditioned by medieval metallurgical activity—a case study from Krakow (Poland). Environ Pollut 218:1023–1036. https://doi.org/10.1016/j.envpol.2016.08.053

Kundzewicz ZW, Kanae S, Seneviratne SI, Handmer J, Nicholls N, Peduzzi P, Sherstyukov B (2014) Flood risk and climate change: global and regional perspectives. Hydrol Sci J 59(1):1–28

Kweku D, Bismark O, Maxwell A, Desmond K, Danso K, Oti-Mensah E, Quachie A, Adormaa B (2018) Greenhouse effect: greenhouse gases and their impact on global warming. J Sci Res Reports 17(6):1–9. https://doi.org/10.9734/jsrr/2017/39630

Lac C, Donnelly RP, Masson V, Pal S, Riette S, Donier S, Queguiner S, Tanguy G, Ammoura L, Xueref-Remy I (2013) CO 2 dispersion modelling over Paris region within the CO 2-MEGAPARIS project. Atmos Chem Phys 13(9):4941–4961. https://doi.org/10.5194/acp-13-4941-2013

Lakshmi DD, Satyanarayana ANV, Chakraborty A (2019) Assessment of heavy precipitation events associated with floods due to strong moisture transport during summer monsoon over India. J Atmos Solar-Terrestrial Phys 189:123–140. https://doi.org/10.1016/j.jastp.2019.04.013

Lamsal MR (2017) Siesmic activity and its periphery. Himal Phys 86–91. https://doi.org/10.3126/hj.v6i0.18367

Landsberg HE (1982) The urban climate. Urban Clim. https://doi.org/10.1016/0304-4009(83)90022-0

Law KS, Stohl A (2007) Arctic air pollution: origins and impacts. Sci (80-. )315:1537–1540

Lee BJ (2017) Analysis on Inundation characteristics for flood impact forecasting in Gangnam drainage basin. Atmos-Korea 27(2):189–197

Lefohn AS, Malley CS, Smith L, Wells B, Hazucha M, Simon H, Naik V, Mills G, Schultz MG, Paoletti E, De Marco A, Xu X, Zhang L, Wang T, Neufeld HS, Musselman RC, Tarasick D, Brauer M, Feng Z, Tang H, Kobayashi K, Sicard P, Solberg S, Gerosa G (2018) Tropospheric ozone assessment report: Global ozone metrics for climate change, human health, and crop/ecosystem research. Elementa 6. https://doi.org/10.1525/elementa.279

Lelieveld J, Pozzer A, Pöschl U, Fnais M, Haines A, Münzel T (2020) Loss of life expectancy from air pollution compared to other risk factors: a worldwide perspective. Cardiovasc Res 116(11):1910–1917

Li D, Bou-Zeid E, Oppenheimer M (2014) The effectiveness of cool and green roofs as urban heat island mitigation strategies. Environ Res Lett 9(5). https://doi.org/10.1088/1748-9326/9/5/055002

Liang L, Wang Z, Li J (2019) The effect of urbanization on environmental pollution in rapidly developing urban agglomerations. J Clean Prod 237. https://doi.org/10.1016/j.jclepro.2019.117649

Livesley SJ, McPherson EG, Calfapietra C (2016) The urban forest and ecosystem services: impacts on urban water, heat, and pollution cycles at the tree, street, and city scale. J Environ Qual 45(1):119–124. https://doi.org/10.2134/jeq2015.11.0567

Livingston RA (2016) Acid rain attack on outdoor sculpture in perspective. Atmos Environ 146:332–345

Lu K, Hou M, Jiang Z, Wang Q, Sun G, Liu J (2018) Understanding earthquake from the granular physics point of view-Causes of earthquake, earthquake precursors and predictions. Int J Mod Phys B 32(7). https://doi.org/10.1142/S0217979218500819

Luo Y, Ampuero JP, Miyakoshi K, Irikura K (2017) Surface rupture effects on earthquake moment-area scaling relations. Pure Appl Geophys 174(9):3331–3342. https://doi.org/10.1007/s00024-017-1467-4

Mahapatra R (2020) Flood cost India Rs 4.7 lakh Crore in last 6 decades. Down To Earth. Retreived from https://www.downtoearth.org.in/blog/climate-change/floods-cost-india-rs-4-7-lakh-crore-in-last-6-decades-72401 . Accessed 10 Sept 2020

Maji KJ, Dikshit AK, Deshpande A (2017) Assessment of city level human health impact and corresponding monetary cost burden due to air pollution in India taking Agra as a model city. Aerosol Air Qual Res 17(3):831–842. https://doi.org/10.4209/aaqr.2016.02.0067

Majumdar SJ, Sun J, Golding B, Joe P, Dudhia J, Caumont O, Yussouf N (2020) Multiscale forecasting of high-impact weather: current status and future challenges. Bull Am Meteorol Soc 1–65

Marzadori C, Ciavatta C, Montecchio D, Gessa C (1996) Effects of lead pollution on different soil enzyme activities. Biol Fertil Soils 22(1–2):53–58. https://doi.org/10.1007/BF00384432

Mathew A, Khandelwal S, Kaul N (2016) Spatial and temporal variations of urban heat island effect and the effect of percentage impervious surface area and elevation on land surface temperature: Study of Chandigarh city, India. Sustain Cities Soc 26:264–277. https://doi.org/10.1016/j.scs.2016.06.018

Menon M, Hermle S, Günthardt-Goerg MS, Schulin R (2007) Effects of heavy metal soil pollution and acid rain on growth and water use efficiency of a young model forest ecosystem. Plant Soil 297(1–2):171–183. https://doi.org/10.1007/s11104-007-9331-4

Merklinger-Gruchala A, Jasienska G, Kapiszewska M (2017) Effect of air pollution on menstrual cycle length-a prognostic factor of women’s reproductive health. Int J Environ Res Public Health 14(7). https://doi.org/10.3390/ijerph14070816

Middel A, Chhetri N, Quay R (2015) Urban forestry and cool roofs: assessment of heat mitigation strategies in Phoenix residential neighborhoods. Urban Urban Green 14(1):178–186. https://doi.org/10.1016/j.ufug.2014.09.010

Millennium Ecosystem Assessment (2005) Ecosystems and human well-being: Wetlands and water synthesis

Ministry of Home and Urban Affairs (2020) Government of India. Retrieved from. http://mohua.gov.in/ . Accessed 21 Oct 2020

Mireles F, Davila JI, Pinedo JL, Reyes E, Speakman RJ, Glascock MD (2012) Assessing urban soil pollution in the cities of Zacatecas and Guadalupe, Mexico by instrumental neutron activation analysis. Microchem J 103:158–164. https://doi.org/10.1016/j.microc.2012.02.009

Mirza M (2011) Climate change, flooding in South Asia and implications. Reg Environ Change 11:95–107

Mirzaei PA, Haghighat F (2010) Approaches to study urban heat island—abilities and limitations. Build Environ 45(10):2192–2201. https://doi.org/10.1016/j.buildenv.2010.04.001

Moftakhari HR, AghaKouchak A, Sanders BF, Allaire M, Matthew RA (2018) What is nuisance flooding? Defining and monitoring an emerging challenge. Water Resour Res 54:4218–4227

Mohajan H (2018) Acid rain is a local environment pollution but global concern

Mohajerani A, Bakaric J, Jeffrey-Bailey T (2017) The urban heat island effect, its causes, and mitigation, with reference to the thermal properties of asphalt concrete. J Environ Manage 197:522–538

Mohammadi AA, Zarei A, Esmaeilzadeh M, Taghavi M, Yousefi M, Yousefi Z, Sedighi F, Javan S (2020) Assessment of heavy metal pollution and human health risks assessment in soils around an industrial zone in Neyshabur, Iran. Biol Trace Elem Res 195(1):343–352. https://doi.org/10.1007/s12011-019-01816-1

Mohan M, Kikegawa Y, Gurjar BR, Bhati S, Kandya A, Ogawa K (2012) Urban Heat Island assessment for a tropical urban Airshed in India. Atmos Clim Sci 02(02):127–138. https://doi.org/10.4236/acs.2012.22014

Mohan M, Sati AP, Bhati S (2020) Urban sprawl during five decadal period over National Capital Region of India: impact on urban heat island and thermal comfort. Urban Clim 33:100647. https://doi.org/10.1016/j.uclim.2020.100647

Mohanty MP, Vittal H, Yadav V, Ghosh S, Rao, GS, Karmakar S (2020) A new bivariate risk classifier for flood management considering hazard and socio-economic dimensions. J Environ Manage 255. https://doi.org/10.1016/j.jenvman.2019.109733

Mondal S, Patel PP (2018) Examining the utility of river restoration approaches for flood mitigation and channel stability enhancement: a recent review. Environ Earth Sci 77(5):195

Mushtaq B, Bandh SA, Shafi S, Mushtaq B, Bandh SA, Shafi S (2020) Environmental acts and legislation. Environ Manage 149–184

Nabi G, Ali M, Khan S, Kumar S (2019) The crisis of water shortage and pollution in Pakistan: risk to public health, biodiversity, and ecosystem. Environ Sci Pollut Res 26:10443–10445

Nahmani J, Lavelle P (2002) Effects of heavy metal pollution on soil macrofauna in a grassland of Northern France. Eur J Soil Biol 38(3–4):297–300. https://doi.org/10.1016/S1164-5563(02)01169-X

NDMA (National Disaster Management Authority) (2007) Guidelines on management of earthquakes, ministry of health and family affairs, Government of India. https://ndma.gov.in/images/guidelines/earthquakes.pdf Accessed 12 Sept 2020

NDMA (National Disaster Management Authority) (2008) National disaster management guidelines: management of floods. National Disaster Management Authority, Government of India, New Delhi. https://ndma.gov.in/en/2013-05-03-08-06-02/disaster/natural-disaster/floods.html Accessed 20 Sept 2020

Nowak DJ, Hirabayashi S, Doyle M, McGovern M, Pasher J (2018) Air pollution removal by urban forests in Canada and its effect on air quality and human health. Urban Urban Green 29:40–48. https://doi.org/10.1016/j.ufug.2017.10.019

Nuruzzaman M (2015) Urban heat Island: causes, effects and mitigation measures—a review. Int J Environ Monit Anal 3(2):67. https://doi.org/10.11648/j.ijema.20150302.15

Oke TR (1995) The heat Island of the urban boundary layer: characteristics, causes and effects. Wind climate in cities. Springer, Netherlands, pp 81–107

Chapter   Google Scholar  

Oke TR, Cleugh HA (1987) Urban heat storage derived as energy balance residuals. Bound-Layer Meteorol 39(3):233–245

Panda PK, Panda RB, Dash PK (2018) The river water pollution in India & abroad-a critical review to study the relationship among different physico-chemical parameters. article.journalofwaterresources.com 6(1):25–38

Pandey AK, Singh S, Berwal S, Kumar D, Pandey P, Prakash A, Lodhi N, Maithani S, Jain VK, Kumar K (2014) Spatio–temporal variations of urban heat island over Delhi. Urban Clim 10:119–133

Patel DP, Srivastava PK, Singh SK, Prieto C, Han D (2020) One‐dimensional hydrodynamic modeling of the river Tapi: the 2006 flood, Surat, India. Tech Disaster Risk Manag Mitig 209–235

Peng C, Ouyang Z, Wang M, Chen W, Li X, Crittenden JC (2013) Assessing the combined risks of PAHs and metals in urban soils by urbanization indicators. Environ Pollut 178:426–432. https://doi.org/10.1016/j.envpol.2013.03.058

Population Reference Bureau (2007) World population highlights : key findings from PRB’s 2007 world population data sheet. Popul Bull 62(3):3–16

Pratap S, Srivastava PK, Routray A, Islam T, Mall RK (2020) Appraisal of hydro-meteorological factors during extreme precipitation event: case study of Kedarnath cloudburst, Uttarakhand, India. Nat Hazards 100(2):635–654. https://doi.org/10.1007/s11069-019-03829-4

Priyadarsini R (2009) Urban heat island and its impact on building energy consumption. Adv Build Energy Res 3(1):261–270. https://doi.org/10.3763/aber.2009.0310

Rabl A (1999) Air pollution and buildings: an estimation of damage costs in France. Environ Impact Assess Rev 19(4):361–385. https://doi.org/10.1016/S0195-9255(98)00040-7

Ramachandra TV, Bharath HA, Kulkarni G, Han SS (2018) Municipal solid waste: Generation, composition and GHG emissions in Bangalore, India. Renew Sustain Energy Rev 82:1122–1136

Rani G, Kaur J, Kumar A, Yogalakshmi KN (2019) Ecosystem health and dynamics: an indicator of global climate change. Contemp Environ Issues Chall Era Clim Chang 1–32

Redd NT (2017) Flood facts, types of flooding, floods in history. Livescience. Retreived from https://www.livescience.com/23913-flood-facts.html . Accessed 17 Sept 2020

Ren L, Cui E, Sun H (2014) Temporal and spatial variations in the relationship between urbanization and water quality. Environ Sci Pollut Res 21(23):13646–13655. https://doi.org/10.1007/s11356-014-3242-8

Rizwan SA, Nongkynrih B, Gupta SK (2013) Air pollution in Delhi: Its magnitude and effects on health. Indian J Community Med 38(1):4–8. https://doi.org/10.4103/0970-0218.106617

Rodríguez-Eugenio N, McLaughlin M, Pennock D (2018) Soil pollution: a hidden reality. Obtenido de. http://www.fao.org/3/I9183EN/i9183en.pdf

Ronik Ketankumar P, Sharareh K, Mostafa N (2020) A socioeconomic-based analysis of disaster preparedness, awareness and education, 76–84

Rosenzweig B, Ruddell BL, McPhillips L, Hobbins R, McPhearson T, Cheng Z, Chang H, Kim Y (2019) Developing knowledge systems for urban resilience to cloudburst rain events. Environ Sci Policy 99:150–159. https://doi.org/10.1016/j.envsci.2019.05.020

Rudiarto I, Handayani W, Setyono JS (2018) A regional perspective on urbanization and climate-related disasters in the northern coastal region of central Java, Indonesia. Land 7(1). https://doi.org/10.3390/land7010034

Salgot M, Folch M (2018) Wastewater treatment and water reuse. Curr Opin Environ Sci Heal 2:64–74

Sanderson D (2000) Cities, disasters and livelihoods. Environ Urban 12(2):93–102. https://doi.org/10.1177/095624780001200208

Santamouris M (2014) On the energy impact of urban heat island and global warming on buildings. Energy Build 82:100–113. https://doi.org/10.1016/j.enbuild.2014.07.022

Sarkar D, Shikha, Rakesh S, Ganguly S, Rakshit A (2017) Management of increasing soil pollution in the ecosystem. Adv Res 12(2):1–9. https://doi.org/10.9734/air/2017/36622

Sarrat C, Lemonsu A, Masson V, Guedalia D (2006) Impact of urban heat island on regional atmospheric pollution. Atmos Environ 40(10):1743–1758. https://doi.org/10.1016/j.atmosenv.2005.11.037

Schwarzenbach RP, Egli T, Hofstetter TB, Von Gunten U, Wehrli B (2010) Global water pollution and human health. Annu Rev Environ Resour 35:109–136. https://doi.org/10.1146/annurev-environ-100809-125342

Shah SI, Arooj F (2019) Outdoor air quality as influenced by vehicular exhaust in metropolitan city of Lahore, Pakistan. Pak J Sci & Ind Res Ser A. Phys Sci 62(3):190–196

Shah AA, Qadri T, Khwaja S (2018) Living with earthquake hazards in South and South East Asia. Asean J Community Engagem 2(1):15. https://doi.org/10.7454/ajce.v2i1.105

Shahmohamadi P, Che-Ani AI, Ramly A, Maulud KNA, Mohd-Nor MFI (2010) Reducing urban heat island effects: a systematic review to achieve energy consumption balance. Int J Phys Sci 5(6):626–636

Sharma B, Singh S, Siddiqi NJ (2014) Biomedical implications of heavy metals induced imbalances in redox systems. Biomed Res Int

Sharma S, Jha PK, Ranjan MR, Singh UK, Kumar M, Jindal T (2017) Nutrient chemistry of river Yamuna, India. Asian J Water, Environ Pollut 14(2):61–70. https://doi.org/10.3233/AJW-170016

Sharma R, Yadav A, Ramteke S, Patel KS, Lata L, Milosh H, Martín-Ramos P (2019) Heavy metal pollution in surface soil of Korba Basin, India. J Hazard Toxic Radioact Waste 23(4):05019004

Singh AA, Agrawal SB (2017) Tropospheric ozone pollution in India: effects on crop yield and product quality. Environ Sci Pollut Res 24(5):4367–4382. https://doi.org/10.1007/s11356-016-8178-8

Singh AK, Gupta HK, Gupta K, Singh P, Gupta VB, Sharma RC (2007) A comparative study of air pollution in Indian cities. Bull Environ Contam Toxicol 78(5):411–416. https://doi.org/10.1007/s00128-007-9220-9

Singh P, Kikon N, Verma P (2017) Impact of land use change and urbanization on urban heat island in Lucknow city, Central India. A remote sensing based estimate. Sustain Cities Soc 32:100–114. https://doi.org/10.1016/j.scs.2017.02.018

Singh P, Sinha VSP, Vijhani A, Pahuja N (2018) Vulnerability assessment of urban road network from urban flood. Int J Disaster Risk Reduct 28:237–250

Streutker DR (2002) A remote sensing study of the urban heat island of Houston, Texas. Int J Remote Sens 23(13):2595–2608. https://doi.org/10.1080/01431160110115023

Sultana S, Satyanarayana ANV (2019) Impact of urbanisation on urban heat island intensity during summer and winter over Indian metropolitan cities. Environ Monit Assess 191. https://doi.org/10.1007/s10661-019-7692-9

Susca T, Gaffin SR, Dell’Osso GR (2011) Positive effects of vegetation: Urban heat island and green roofs. Environ Pollut 159(8–9):2119–2126. https://doi.org/10.1016/j.envpol.2011.03.007

Svetlanaa D, Radovana D, Ján D (2015) The economic impact of floods and their importance indifferent regions of the world with emphasis on Europe. Procedia Econ Finan 34:649–655

Taha H (1997) Urban climates and heat islands: Albedo, evapotranspiration, and anthropogenic heat. Energy Build 25(2):99–103. https://doi.org/10.1016/s0378-7788(96)00999-1

Taha H, Akbari H, Rosenfeld A, Huang J (1988) Residential cooling loads and the urban heat island-the effects of albedo. Build Environ 23(4):271–283. https://doi.org/10.1016/0360-1323(88)90033-9

Takeuchi I, Kakumoto S, Goto Y (2003) Towards an integrated earthquake disaster simulation system. First Int Work Synth Simul Robot to Mitigate Earthq Disaster

Tan J, Zheng Y, Tang X, Guo C, Li L, Song G, Zhen X, Yuan D, Kalkstein AJ, Li F, Chen H (2010) The urban heat island and its impact on heat waves and human health in Shanghai. Int J Biometeorol 54(1):75–84. https://doi.org/10.1007/s00484-009-0256-x

Tisserant A, Pauliuk S, Merciai S, Schmidt J, Fry J, Wood R, Tukker A (2017) Solid waste and the circular economy: a global analysis of waste treatment and waste footprints. J Ind Ecol 21(3):628–640. https://doi.org/10.1111/jiec.12562

Tiwari G, Jangir A, Malav LC, Kumar S (2020) Soil biodiversity: status, indicators and threats

Torti JMI (2012) Floods in Southeast Asia: a health priority. J Glob Health 2(2). https://doi.org/10.7189/jogh.02.020304

Tournebize J, Chaumont C, Mander Ü (2017) Implications for constructed wetlands to mitigate nitrate and pesticide pollution in agricultural drained watersheds. Ecol Eng 103:415–425. https://doi.org/10.1016/j.ecoleng.2016.02.014

Tran H, Uchihama D, Ochi S, Yasuoka Y (2006) Assessment with satellite data of the urban heat island effects in Asian mega cities. Int J Appl Earth Obs Geoinf 8(1):34–48. https://doi.org/10.1016/j.jag.2005.05.003

United Nations (2004) World urbanization prospects: the 2003 revision. United Nations Publication, New York. http://www.un.org/ . Accessed 04 Oct 2020

United Nations Office for Disaster Risk Reduction (2020) The human cost of disasters: an overview of last 20 years (2000–2019). https://www.undrr.org/publication/human-cost-disasters-overview-last-20-years-2000-2019 . Accessed 24 Sept 2020

Vallero DA (2014) Fundamentals of air pollution. Elsevier Inc.

Vargo J, Stone B, Habeeb D, Liu P, Russell A (2016) The social and spatial distribution of temperature-related health impacts from urban heat island reduction policies. Environ Sci Policy 66:366–374. https://doi.org/10.1016/j.envsci.2016.08.012

Waghwala RK, Agnihotri PG (2019) Flood risk assessment and resilience strategies for flood risk management: a case study of Surat City. Int J Disaster Risk Reduct 40. https://doi.org/10.1016/j.ijdrr.2019.101155

Wang X, Mauzerall DL (2006) Evaluating impacts of air pollution in China on public health: Implications for future air pollution and energy policies. Atmos Environ 40(9):1706–1721. https://doi.org/10.1016/j.atmosenv.2005.10.066

Wang W, Zhou W, Ng EYY, Xu Y (2016a) Urban heat islands in Hong Kong: statistical modeling and trend detection. Nat Hazards 83(2):885–907

Wang Y, Berardi U, Akbari H (2016) Comparing the effects of urban heat island mitigation strategies for Toronto, Canada. Energy Build 114:2–19. https://doi.org/10.1016/j.enbuild.2015.06.046

Wang B, Shugart HH, Lerdau MT (2017) Sensitivity of global greenhouse gas budgets to tropospheric ozone pollution mediated by the biosphere. Environ Res Lett 12(8). https://doi.org/10.1088/1748-9326/aa7885

Wang Z, Cui C, Peng S (2019) How do urbanization and consumption patterns affect carbon emissions in China? A decomposition analysis. J Clean Prod 211:1201–1208. https://doi.org/10.1016/j.jclepro.2018.11.272

Wang S, Gao S, Li S, Feng K (2020) Strategizing the relation between urbanization and air pollution: empirical evidence from global countries. J Clean Prod 243:118–615. https://doi.org/10.1016/j.jclepro.2019.118615

Watkins R, Palmer J, Kolokotroni M, Littlefair P (2002) The balance of the annual heating and cooling demand within the London urban heat island. Build Serv Eng Res Technol 207–213

Wei H, Liu W, Zhang J, Qin Z (2017) Effects of simulated acid rain on soil fauna community composition and their ecological niches. Environ Pollut 220:460–468. https://doi.org/10.1016/j.envpol.2016.09.088

Wen Y, Schoups G, Van De Giesen N (2017) Organic pollution of rivers: combined threats of urbanization, livestock farming and global climate change. Sci Rep 7. https://doi.org/10.1038/srep43289

Weng Q, Lu D, Schubring J (2004) Estimation of land surface temperature-vegetation abundance relationship for urban heat island studies. Remote Sens Environ 89(4):467–483. https://doi.org/10.1016/j.rse.2003.11.005

WHO and UNICEF (2000) Global water supply and sanitation assessment 2000 report. WHO/UNICEF joint monitoring programme for water supply and sanitation (ISBN 9241562021)

Wong NH, Yu C (2005) Study of green areas and urban heat island in a tropical city. Habitat Int 29(3):547–558

Wong LP, Alias H, Aghamohammadi N, Aghazadeh S, Nik Sulaiman NM (2017) Urban heat island experience, control measures and health impact: A survey among working community in the city of Kuala Lumpur. Sustain Cities Soc 35:660–668. https://doi.org/10.1016/j.scs.2017.09.026

Wu W, Yun Y, Hu B, Sun Y, Xiao Y (2020a) Greenness, perceived pollution hazards and subjective wellbeing: Evidence from China. Urban for Urban Green 56:126796

Wu H, Gai Z, Guo Y, Li Y, Hao Y, Lu ZN (2020b) Does environmental pollution inhibit urbanization in China? A new perspective through residents’ medical and health costs. Environ Res 182:109–128. https://doi.org/10.1016/j.envres.2020.109128

Xia L, Gao Y (2011) Characterization of trace elements in PM2.5 aerosols in the vicinity of highways in northeast New Jersey in the U.S. East coast. Atmos Pollut Res 2(1):34–44. https://doi.org/10.5094/APR.2011.005

Yaalon D (2000) Soil care attitudes and strategies of land use through human history

Yadav N, Sharma C (2018) Spatial variations of intra-city urban heat island in megacity Delhi. Sustain Cities Soc 37:298–306. https://doi.org/10.1016/j.scs.2017.11.026

Yang L, Ma KM, Guo QH, Zhao JZ (2003) Impacts of the urbanization on waters non-point source pollution. Surf Min - Braunkohle Other Miner 55(1):32–39

Yang J, Pyrgou A, Chong A, Santamouris M, Kolokotsa D, Lee SE (2018) Green and cool roofs’ urban heat island mitigation potential in tropical climate. Sol Energy 173:597–609

Yao X, Wei HH, Shohet IM, Skibniewski MJ (2017) Public-private partnership for earthquake mitigation involving retrofit and insurance. Technol Econ Dev Econ 23(6):810–826

Zenker A, Cicero MR, Prestinaci F, Bottoni P, Carere M (2014) Bioaccumulation and biomagnification potential of pharmaceuticals with a focus to the aquatic environment. J Environ Manage 133:378–387

Zhao H, Duan X, Stewart B, You B, Jiang X (2013) Spatial correlations between urbanization and river water pollution in the heavily polluted area of Taihu Lake Basin. China. J Geogr Sci 23(4):735–752. https://doi.org/10.1007/s11442-013-1041-7

Zhu Y, Wang K, He J (2020) Effects of earthquake recurrence on localization of interseismic deformation around locked strike-slip faults. J Geophys Res Solid Earth 125(8). https://doi.org/10.1029/2020JB019817

Zinzi M, Agnoli S (2012) Cool and green roofs. An energy and comfort comparison between passive cooling and mitigation urban heat island techniques for residential buildings in the Mediterranean region. Energy Build , 66–76

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Varma, K., Srivastava, V., Singhal, A., Jha, P.K. (2021). Urban and Environmental Hazards. In: Rai, P.K., Singh, P., Mishra, V.N. (eds) Recent Technologies for Disaster Management and Risk Reduction. Earth and Environmental Sciences Library. Springer, Cham. https://doi.org/10.1007/978-3-030-76116-5_19

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Environmental and Health Impacts of Air Pollution: A Review

Ioannis manisalidis.

1 Delphis S.A., Kifisia, Greece

2 Laboratory of Hygiene and Environmental Protection, Faculty of Medicine, Democritus University of Thrace, Alexandroupolis, Greece

Elisavet Stavropoulou

3 Centre Hospitalier Universitaire Vaudois (CHUV), Service de Médicine Interne, Lausanne, Switzerland

Agathangelos Stavropoulos

4 School of Social and Political Sciences, University of Glasgow, Glasgow, United Kingdom

Eugenia Bezirtzoglou

One of our era's greatest scourges is air pollution, on account not only of its impact on climate change but also its impact on public and individual health due to increasing morbidity and mortality. There are many pollutants that are major factors in disease in humans. Among them, Particulate Matter (PM), particles of variable but very small diameter, penetrate the respiratory system via inhalation, causing respiratory and cardiovascular diseases, reproductive and central nervous system dysfunctions, and cancer. Despite the fact that ozone in the stratosphere plays a protective role against ultraviolet irradiation, it is harmful when in high concentration at ground level, also affecting the respiratory and cardiovascular system. Furthermore, nitrogen oxide, sulfur dioxide, Volatile Organic Compounds (VOCs), dioxins, and polycyclic aromatic hydrocarbons (PAHs) are all considered air pollutants that are harmful to humans. Carbon monoxide can even provoke direct poisoning when breathed in at high levels. Heavy metals such as lead, when absorbed into the human body, can lead to direct poisoning or chronic intoxication, depending on exposure. Diseases occurring from the aforementioned substances include principally respiratory problems such as Chronic Obstructive Pulmonary Disease (COPD), asthma, bronchiolitis, and also lung cancer, cardiovascular events, central nervous system dysfunctions, and cutaneous diseases. Last but not least, climate change resulting from environmental pollution affects the geographical distribution of many infectious diseases, as do natural disasters. The only way to tackle this problem is through public awareness coupled with a multidisciplinary approach by scientific experts; national and international organizations must address the emergence of this threat and propose sustainable solutions.

Approach to the Problem

The interactions between humans and their physical surroundings have been extensively studied, as multiple human activities influence the environment. The environment is a coupling of the biotic (living organisms and microorganisms) and the abiotic (hydrosphere, lithosphere, and atmosphere).

Pollution is defined as the introduction into the environment of substances harmful to humans and other living organisms. Pollutants are harmful solids, liquids, or gases produced in higher than usual concentrations that reduce the quality of our environment.

Human activities have an adverse effect on the environment by polluting the water we drink, the air we breathe, and the soil in which plants grow. Although the industrial revolution was a great success in terms of technology, society, and the provision of multiple services, it also introduced the production of huge quantities of pollutants emitted into the air that are harmful to human health. Without any doubt, the global environmental pollution is considered an international public health issue with multiple facets. Social, economic, and legislative concerns and lifestyle habits are related to this major problem. Clearly, urbanization and industrialization are reaching unprecedented and upsetting proportions worldwide in our era. Anthropogenic air pollution is one of the biggest public health hazards worldwide, given that it accounts for about 9 million deaths per year ( 1 ).

Without a doubt, all of the aforementioned are closely associated with climate change, and in the event of danger, the consequences can be severe for mankind ( 2 ). Climate changes and the effects of global planetary warming seriously affect multiple ecosystems, causing problems such as food safety issues, ice and iceberg melting, animal extinction, and damage to plants ( 3 , 4 ).

Air pollution has various health effects. The health of susceptible and sensitive individuals can be impacted even on low air pollution days. Short-term exposure to air pollutants is closely related to COPD (Chronic Obstructive Pulmonary Disease), cough, shortness of breath, wheezing, asthma, respiratory disease, and high rates of hospitalization (a measurement of morbidity).

The long-term effects associated with air pollution are chronic asthma, pulmonary insufficiency, cardiovascular diseases, and cardiovascular mortality. According to a Swedish cohort study, diabetes seems to be induced after long-term air pollution exposure ( 5 ). Moreover, air pollution seems to have various malign health effects in early human life, such as respiratory, cardiovascular, mental, and perinatal disorders ( 3 ), leading to infant mortality or chronic disease in adult age ( 6 ).

National reports have mentioned the increased risk of morbidity and mortality ( 1 ). These studies were conducted in many places around the world and show a correlation between daily ranges of particulate matter (PM) concentration and daily mortality. Climate shifts and global planetary warming ( 3 ) could aggravate the situation. Besides, increased hospitalization (an index of morbidity) has been registered among the elderly and susceptible individuals for specific reasons. Fine and ultrafine particulate matter seems to be associated with more serious illnesses ( 6 ), as it can invade the deepest parts of the airways and more easily reach the bloodstream.

Air pollution mainly affects those living in large urban areas, where road emissions contribute the most to the degradation of air quality. There is also a danger of industrial accidents, where the spread of a toxic fog can be fatal to the populations of the surrounding areas. The dispersion of pollutants is determined by many parameters, most notably atmospheric stability and wind ( 6 ).

In developing countries ( 7 ), the problem is more serious due to overpopulation and uncontrolled urbanization along with the development of industrialization. This leads to poor air quality, especially in countries with social disparities and a lack of information on sustainable management of the environment. The use of fuels such as wood fuel or solid fuel for domestic needs due to low incomes exposes people to bad-quality, polluted air at home. It is of note that three billion people around the world are using the above sources of energy for their daily heating and cooking needs ( 8 ). In developing countries, the women of the household seem to carry the highest risk for disease development due to their longer duration exposure to the indoor air pollution ( 8 , 9 ). Due to its fast industrial development and overpopulation, China is one of the Asian countries confronting serious air pollution problems ( 10 , 11 ). The lung cancer mortality observed in China is associated with fine particles ( 12 ). As stated already, long-term exposure is associated with deleterious effects on the cardiovascular system ( 3 , 5 ). However, it is interesting to note that cardiovascular diseases have mostly been observed in developed and high-income countries rather than in the developing low-income countries exposed highly to air pollution ( 13 ). Extreme air pollution is recorded in India, where the air quality reaches hazardous levels. New Delhi is one of the more polluted cities in India. Flights in and out of New Delhi International Airport are often canceled due to the reduced visibility associated with air pollution. Pollution is occurring both in urban and rural areas in India due to the fast industrialization, urbanization, and rise in use of motorcycle transportation. Nevertheless, biomass combustion associated with heating and cooking needs and practices is a major source of household air pollution in India and in Nepal ( 14 , 15 ). There is spatial heterogeneity in India, as areas with diverse climatological conditions and population and education levels generate different indoor air qualities, with higher PM 2.5 observed in North Indian states (557–601 μg/m 3 ) compared to the Southern States (183–214 μg/m 3 ) ( 16 , 17 ). The cold climate of the North Indian areas may be the main reason for this, as longer periods at home and more heating are necessary compared to in the tropical climate of Southern India. Household air pollution in India is associated with major health effects, especially in women and young children, who stay indoors for longer periods. Chronic obstructive respiratory disease (CORD) and lung cancer are mostly observed in women, while acute lower respiratory disease is seen in young children under 5 years of age ( 18 ).

Accumulation of air pollution, especially sulfur dioxide and smoke, reaching 1,500 mg/m3, resulted in an increase in the number of deaths (4,000 deaths) in December 1952 in London and in 1963 in New York City (400 deaths) ( 19 ). An association of pollution with mortality was reported on the basis of monitoring of outdoor pollution in six US metropolitan cities ( 20 ). In every case, it seems that mortality was closely related to the levels of fine, inhalable, and sulfate particles more than with the levels of total particulate pollution, aerosol acidity, sulfur dioxide, or nitrogen dioxide ( 20 ).

Furthermore, extremely high levels of pollution are reported in Mexico City and Rio de Janeiro, followed by Milan, Ankara, Melbourne, Tokyo, and Moscow ( 19 ).

Based on the magnitude of the public health impact, it is certain that different kinds of interventions should be taken into account. Success and effectiveness in controlling air pollution, specifically at the local level, have been reported. Adequate technological means are applied considering the source and the nature of the emission as well as its impact on health and the environment. The importance of point sources and non-point sources of air pollution control is reported by Schwela and Köth-Jahr ( 21 ). Without a doubt, a detailed emission inventory must record all sources in a given area. Beyond considering the above sources and their nature, topography and meteorology should also be considered, as stated previously. Assessment of the control policies and methods is often extrapolated from the local to the regional and then to the global scale. Air pollution may be dispersed and transported from one region to another area located far away. Air pollution management means the reduction to acceptable levels or possible elimination of air pollutants whose presence in the air affects our health or the environmental ecosystem. Private and governmental entities and authorities implement actions to ensure the air quality ( 22 ). Air quality standards and guidelines were adopted for the different pollutants by the WHO and EPA as a tool for the management of air quality ( 1 , 23 ). These standards have to be compared to the emissions inventory standards by causal analysis and dispersion modeling in order to reveal the problematic areas ( 24 ). Inventories are generally based on a combination of direct measurements and emissions modeling ( 24 ).

As an example, we state here the control measures at the source through the use of catalytic converters in cars. These are devices that turn the pollutants and toxic gases produced from combustion engines into less-toxic pollutants by catalysis through redox reactions ( 25 ). In Greece, the use of private cars was restricted by tracking their license plates in order to reduce traffic congestion during rush hour ( 25 ).

Concerning industrial emissions, collectors and closed systems can keep the air pollution to the minimal standards imposed by legislation ( 26 ).

Current strategies to improve air quality require an estimation of the economic value of the benefits gained from proposed programs. These proposed programs by public authorities, and directives are issued with guidelines to be respected.

In Europe, air quality limit values AQLVs (Air Quality Limit Values) are issued for setting off planning claims ( 27 ). In the USA, the NAAQS (National Ambient Air Quality Standards) establish the national air quality limit values ( 27 ). While both standards and directives are based on different mechanisms, significant success has been achieved in the reduction of overall emissions and associated health and environmental effects ( 27 ). The European Directive identifies geographical areas of risk exposure as monitoring/assessment zones to record the emission sources and levels of air pollution ( 27 ), whereas the USA establishes global geographical air quality criteria according to the severity of their air quality problem and records all sources of the pollutants and their precursors ( 27 ).

In this vein, funds have been financing, directly or indirectly, projects related to air quality along with the technical infrastructure to maintain good air quality. These plans focus on an inventory of databases from air quality environmental planning awareness campaigns. Moreover, pollution measures of air emissions may be taken for vehicles, machines, and industries in urban areas.

Technological innovation can only be successful if it is able to meet the needs of society. In this sense, technology must reflect the decision-making practices and procedures of those involved in risk assessment and evaluation and act as a facilitator in providing information and assessments to enable decision makers to make the best decisions possible. Summarizing the aforementioned in order to design an effective air quality control strategy, several aspects must be considered: environmental factors and ambient air quality conditions, engineering factors and air pollutant characteristics, and finally, economic operating costs for technological improvement and administrative and legal costs. Considering the economic factor, competitiveness through neoliberal concepts is offering a solution to environmental problems ( 22 ).

The development of environmental governance, along with technological progress, has initiated the deployment of a dialogue. Environmental politics has created objections and points of opposition between different political parties, scientists, media, and governmental and non-governmental organizations ( 22 ). Radical environmental activism actions and movements have been created ( 22 ). The rise of the new information and communication technologies (ICTs) are many times examined as to whether and in which way they have influenced means of communication and social movements such as activism ( 28 ). Since the 1990s, the term “digital activism” has been used increasingly and in many different disciplines ( 29 ). Nowadays, multiple digital technologies can be used to produce a digital activism outcome on environmental issues. More specifically, devices with online capabilities such as computers or mobile phones are being used as a way to pursue change in political and social affairs ( 30 ).

In the present paper, we focus on the sources of environmental pollution in relation to public health and propose some solutions and interventions that may be of interest to environmental legislators and decision makers.

Sources of Exposure

It is known that the majority of environmental pollutants are emitted through large-scale human activities such as the use of industrial machinery, power-producing stations, combustion engines, and cars. Because these activities are performed at such a large scale, they are by far the major contributors to air pollution, with cars estimated to be responsible for approximately 80% of today's pollution ( 31 ). Some other human activities are also influencing our environment to a lesser extent, such as field cultivation techniques, gas stations, fuel tanks heaters, and cleaning procedures ( 32 ), as well as several natural sources, such as volcanic and soil eruptions and forest fires.

The classification of air pollutants is based mainly on the sources producing pollution. Therefore, it is worth mentioning the four main sources, following the classification system: Major sources, Area sources, Mobile sources, and Natural sources.

Major sources include the emission of pollutants from power stations, refineries, and petrochemicals, the chemical and fertilizer industries, metallurgical and other industrial plants, and, finally, municipal incineration.

Indoor area sources include domestic cleaning activities, dry cleaners, printing shops, and petrol stations.

Mobile sources include automobiles, cars, railways, airways, and other types of vehicles.

Finally, natural sources include, as stated previously, physical disasters ( 33 ) such as forest fire, volcanic erosion, dust storms, and agricultural burning.

However, many classification systems have been proposed. Another type of classification is a grouping according to the recipient of the pollution, as follows:

Air pollution is determined as the presence of pollutants in the air in large quantities for long periods. Air pollutants are dispersed particles, hydrocarbons, CO, CO 2 , NO, NO 2 , SO 3 , etc.

Water pollution is organic and inorganic charge and biological charge ( 10 ) at high levels that affect the water quality ( 34 , 35 ).

Soil pollution occurs through the release of chemicals or the disposal of wastes, such as heavy metals, hydrocarbons, and pesticides.

Air pollution can influence the quality of soil and water bodies by polluting precipitation, falling into water and soil environments ( 34 , 36 ). Notably, the chemistry of the soil can be amended due to acid precipitation by affecting plants, cultures, and water quality ( 37 ). Moreover, movement of heavy metals is favored by soil acidity, and metals are so then moving into the watery environment. It is known that heavy metals such as aluminum are noxious to wildlife and fishes. Soil quality seems to be of importance, as soils with low calcium carbonate levels are at increased jeopardy from acid rain. Over and above rain, snow and particulate matter drip into watery ' bodies ( 36 , 38 ).

Lastly, pollution is classified following type of origin:

Radioactive and nuclear pollution , releasing radioactive and nuclear pollutants into water, air, and soil during nuclear explosions and accidents, from nuclear weapons, and through handling or disposal of radioactive sewage.

Radioactive materials can contaminate surface water bodies and, being noxious to the environment, plants, animals, and humans. It is known that several radioactive substances such as radium and uranium concentrate in the bones and can cause cancers ( 38 , 39 ).

Noise pollution is produced by machines, vehicles, traffic noises, and musical installations that are harmful to our hearing.

The World Health Organization introduced the term DALYs. The DALYs for a disease or health condition is defined as the sum of the Years of Life Lost (YLL) due to premature mortality in the population and the Years Lost due to Disability (YLD) for people living with the health condition or its consequences ( 39 ). In Europe, air pollution is the main cause of disability-adjusted life years lost (DALYs), followed by noise pollution. The potential relationships of noise and air pollution with health have been studied ( 40 ). The study found that DALYs related to noise were more important than those related to air pollution, as the effects of environmental noise on cardiovascular disease were independent of air pollution ( 40 ). Environmental noise should be counted as an independent public health risk ( 40 ).

Environmental pollution occurs when changes in the physical, chemical, or biological constituents of the environment (air masses, temperature, climate, etc.) are produced.

Pollutants harm our environment either by increasing levels above normal or by introducing harmful toxic substances. Primary pollutants are directly produced from the above sources, and secondary pollutants are emitted as by-products of the primary ones. Pollutants can be biodegradable or non-biodegradable and of natural origin or anthropogenic, as stated previously. Moreover, their origin can be a unique source (point-source) or dispersed sources.

Pollutants have differences in physical and chemical properties, explaining the discrepancy in their capacity for producing toxic effects. As an example, we state here that aerosol compounds ( 41 – 43 ) have a greater toxicity than gaseous compounds due to their tiny size (solid or liquid) in the atmosphere; they have a greater penetration capacity. Gaseous compounds are eliminated more easily by our respiratory system ( 41 ). These particles are able to damage lungs and can even enter the bloodstream ( 41 ), leading to the premature deaths of millions of people yearly. Moreover, the aerosol acidity ([H+]) seems to considerably enhance the production of secondary organic aerosols (SOA), but this last aspect is not supported by other scientific teams ( 38 ).

Climate and Pollution

Air pollution and climate change are closely related. Climate is the other side of the same coin that reduces the quality of our Earth ( 44 ). Pollutants such as black carbon, methane, tropospheric ozone, and aerosols affect the amount of incoming sunlight. As a result, the temperature of the Earth is increasing, resulting in the melting of ice, icebergs, and glaciers.

In this vein, climatic changes will affect the incidence and prevalence of both residual and imported infections in Europe. Climate and weather affect the duration, timing, and intensity of outbreaks strongly and change the map of infectious diseases in the globe ( 45 ). Mosquito-transmitted parasitic or viral diseases are extremely climate-sensitive, as warming firstly shortens the pathogen incubation period and secondly shifts the geographic map of the vector. Similarly, water-warming following climate changes leads to a high incidence of waterborne infections. Recently, in Europe, eradicated diseases seem to be emerging due to the migration of population, for example, cholera, poliomyelitis, tick-borne encephalitis, and malaria ( 46 ).

The spread of epidemics is associated with natural climate disasters and storms, which seem to occur more frequently nowadays ( 47 ). Malnutrition and disequilibration of the immune system are also associated with the emerging infections affecting public health ( 48 ).

The Chikungunya virus “took the airplane” from the Indian Ocean to Europe, as outbreaks of the disease were registered in Italy ( 49 ) as well as autochthonous cases in France ( 50 ).

An increase in cryptosporidiosis in the United Kingdom and in the Czech Republic seems to have occurred following flooding ( 36 , 51 ).

As stated previously, aerosols compounds are tiny in size and considerably affect the climate. They are able to dissipate sunlight (the albedo phenomenon) by dispersing a quarter of the sun's rays back to space and have cooled the global temperature over the last 30 years ( 52 ).

Air Pollutants

The World Health Organization (WHO) reports on six major air pollutants, namely particle pollution, ground-level ozone, carbon monoxide, sulfur oxides, nitrogen oxides, and lead. Air pollution can have a disastrous effect on all components of the environment, including groundwater, soil, and air. Additionally, it poses a serious threat to living organisms. In this vein, our interest is mainly to focus on these pollutants, as they are related to more extensive and severe problems in human health and environmental impact. Acid rain, global warming, the greenhouse effect, and climate changes have an important ecological impact on air pollution ( 53 ).

Particulate Matter (PM) and Health

Studies have shown a relationship between particulate matter (PM) and adverse health effects, focusing on either short-term (acute) or long-term (chronic) PM exposure.

Particulate matter (PM) is usually formed in the atmosphere as a result of chemical reactions between the different pollutants. The penetration of particles is closely dependent on their size ( 53 ). Particulate Matter (PM) was defined as a term for particles by the United States Environmental Protection Agency ( 54 ). Particulate matter (PM) pollution includes particles with diameters of 10 micrometers (μm) or smaller, called PM 10 , and extremely fine particles with diameters that are generally 2.5 micrometers (μm) and smaller.

Particulate matter contains tiny liquid or solid droplets that can be inhaled and cause serious health effects ( 55 ). Particles <10 μm in diameter (PM 10 ) after inhalation can invade the lungs and even reach the bloodstream. Fine particles, PM 2.5 , pose a greater risk to health ( 6 , 56 ) ( Table 1 ).

Penetrability according to particle size.

Multiple epidemiological studies have been performed on the health effects of PM. A positive relation was shown between both short-term and long-term exposures of PM 2.5 and acute nasopharyngitis ( 56 ). In addition, long-term exposure to PM for years was found to be related to cardiovascular diseases and infant mortality.

Those studies depend on PM 2.5 monitors and are restricted in terms of study area or city area due to a lack of spatially resolved daily PM 2.5 concentration data and, in this way, are not representative of the entire population. Following a recent epidemiological study by the Department of Environmental Health at Harvard School of Public Health (Boston, MA) ( 57 ), it was reported that, as PM 2.5 concentrations vary spatially, an exposure error (Berkson error) seems to be produced, and the relative magnitudes of the short- and long-term effects are not yet completely elucidated. The team developed a PM 2.5 exposure model based on remote sensing data for assessing short- and long-term human exposures ( 57 ). This model permits spatial resolution in short-term effects plus the assessment of long-term effects in the whole population.

Moreover, respiratory diseases and affection of the immune system are registered as long-term chronic effects ( 58 ). It is worth noting that people with asthma, pneumonia, diabetes, and respiratory and cardiovascular diseases are especially susceptible and vulnerable to the effects of PM. PM 2.5 , followed by PM 10 , are strongly associated with diverse respiratory system diseases ( 59 ), as their size permits them to pierce interior spaces ( 60 ). The particles produce toxic effects according to their chemical and physical properties. The components of PM 10 and PM 2.5 can be organic (polycyclic aromatic hydrocarbons, dioxins, benzene, 1-3 butadiene) or inorganic (carbon, chlorides, nitrates, sulfates, metals) in nature ( 55 ).

Particulate Matter (PM) is divided into four main categories according to type and size ( 61 ) ( Table 2 ).

Types and sizes of particulate Matter (PM).

Gas contaminants include PM in aerial masses.

Particulate contaminants include contaminants such as smog, soot, tobacco smoke, oil smoke, fly ash, and cement dust.

Biological Contaminants are microorganisms (bacteria, viruses, fungi, mold, and bacterial spores), cat allergens, house dust and allergens, and pollen.

Types of Dust include suspended atmospheric dust, settling dust, and heavy dust.

Finally, another fact is that the half-lives of PM 10 and PM 2.5 particles in the atmosphere is extended due to their tiny dimensions; this permits their long-lasting suspension in the atmosphere and even their transfer and spread to distant destinations where people and the environment may be exposed to the same magnitude of pollution ( 53 ). They are able to change the nutrient balance in watery ecosystems, damage forests and crops, and acidify water bodies.

As stated, PM 2.5 , due to their tiny size, are causing more serious health effects. These aforementioned fine particles are the main cause of the “haze” formation in different metropolitan areas ( 12 , 13 , 61 ).

Ozone Impact in the Atmosphere

Ozone (O 3 ) is a gas formed from oxygen under high voltage electric discharge ( 62 ). It is a strong oxidant, 52% stronger than chlorine. It arises in the stratosphere, but it could also arise following chain reactions of photochemical smog in the troposphere ( 63 ).

Ozone can travel to distant areas from its initial source, moving with air masses ( 64 ). It is surprising that ozone levels over cities are low in contrast to the increased amounts occuring in urban areas, which could become harmful for cultures, forests, and vegetation ( 65 ) as it is reducing carbon assimilation ( 66 ). Ozone reduces growth and yield ( 47 , 48 ) and affects the plant microflora due to its antimicrobial capacity ( 67 , 68 ). In this regard, ozone acts upon other natural ecosystems, with microflora ( 69 , 70 ) and animal species changing their species composition ( 71 ). Ozone increases DNA damage in epidermal keratinocytes and leads to impaired cellular function ( 72 ).

Ground-level ozone (GLO) is generated through a chemical reaction between oxides of nitrogen and VOCs emitted from natural sources and/or following anthropogenic activities.

Ozone uptake usually occurs by inhalation. Ozone affects the upper layers of the skin and the tear ducts ( 73 ). A study of short-term exposure of mice to high levels of ozone showed malondialdehyde formation in the upper skin (epidermis) but also depletion in vitamins C and E. It is likely that ozone levels are not interfering with the skin barrier function and integrity to predispose to skin disease ( 74 ).

Due to the low water-solubility of ozone, inhaled ozone has the capacity to penetrate deeply into the lungs ( 75 ).

Toxic effects induced by ozone are registered in urban areas all over the world, causing biochemical, morphologic, functional, and immunological disorders ( 76 ).

The European project (APHEA2) focuses on the acute effects of ambient ozone concentrations on mortality ( 77 ). Daily ozone concentrations compared to the daily number of deaths were reported from different European cities for a 3-year period. During the warm period of the year, an observed increase in ozone concentration was associated with an increase in the daily number of deaths (0.33%), in the number of respiratory deaths (1.13%), and in the number of cardiovascular deaths (0.45%). No effect was observed during wintertime.

Carbon Monoxide (CO)

Carbon monoxide is produced by fossil fuel when combustion is incomplete. The symptoms of poisoning due to inhaling carbon monoxide include headache, dizziness, weakness, nausea, vomiting, and, finally, loss of consciousness.

The affinity of carbon monoxide to hemoglobin is much greater than that of oxygen. In this vein, serious poisoning may occur in people exposed to high levels of carbon monoxide for a long period of time. Due to the loss of oxygen as a result of the competitive binding of carbon monoxide, hypoxia, ischemia, and cardiovascular disease are observed.

Carbon monoxide affects the greenhouses gases that are tightly connected to global warming and climate. This should lead to an increase in soil and water temperatures, and extreme weather conditions or storms may occur ( 68 ).

However, in laboratory and field experiments, it has been seen to produce increased plant growth ( 78 ).

Nitrogen Oxide (NO 2 )

Nitrogen oxide is a traffic-related pollutant, as it is emitted from automobile motor engines ( 79 , 80 ). It is an irritant of the respiratory system as it penetrates deep in the lung, inducing respiratory diseases, coughing, wheezing, dyspnea, bronchospasm, and even pulmonary edema when inhaled at high levels. It seems that concentrations over 0.2 ppm produce these adverse effects in humans, while concentrations higher than 2.0 ppm affect T-lymphocytes, particularly the CD8+ cells and NK cells that produce our immune response ( 81 ).It is reported that long-term exposure to high levels of nitrogen dioxide can be responsible for chronic lung disease. Long-term exposure to NO 2 can impair the sense of smell ( 81 ).

However, systems other than respiratory ones can be involved, as symptoms such as eye, throat, and nose irritation have been registered ( 81 ).

High levels of nitrogen dioxide are deleterious to crops and vegetation, as they have been observed to reduce crop yield and plant growth efficiency. Moreover, NO 2 can reduce visibility and discolor fabrics ( 81 ).

Sulfur Dioxide (SO 2 )

Sulfur dioxide is a harmful gas that is emitted mainly from fossil fuel consumption or industrial activities. The annual standard for SO 2 is 0.03 ppm ( 82 ). It affects human, animal, and plant life. Susceptible people as those with lung disease, old people, and children, who present a higher risk of damage. The major health problems associated with sulfur dioxide emissions in industrialized areas are respiratory irritation, bronchitis, mucus production, and bronchospasm, as it is a sensory irritant and penetrates deep into the lung converted into bisulfite and interacting with sensory receptors, causing bronchoconstriction. Moreover, skin redness, damage to the eyes (lacrimation and corneal opacity) and mucous membranes, and worsening of pre-existing cardiovascular disease have been observed ( 81 ).

Environmental adverse effects, such as acidification of soil and acid rain, seem to be associated with sulfur dioxide emissions ( 83 ).

Lead is a heavy metal used in different industrial plants and emitted from some petrol motor engines, batteries, radiators, waste incinerators, and waste waters ( 84 ).

Moreover, major sources of lead pollution in the air are metals, ore, and piston-engine aircraft. Lead poisoning is a threat to public health due to its deleterious effects upon humans, animals, and the environment, especially in the developing countries.

Exposure to lead can occur through inhalation, ingestion, and dermal absorption. Trans- placental transport of lead was also reported, as lead passes through the placenta unencumbered ( 85 ). The younger the fetus is, the more harmful the toxic effects. Lead toxicity affects the fetal nervous system; edema or swelling of the brain is observed ( 86 ). Lead, when inhaled, accumulates in the blood, soft tissue, liver, lung, bones, and cardiovascular, nervous, and reproductive systems. Moreover, loss of concentration and memory, as well as muscle and joint pain, were observed in adults ( 85 , 86 ).

Children and newborns ( 87 ) are extremely susceptible even to minimal doses of lead, as it is a neurotoxicant and causes learning disabilities, impairment of memory, hyperactivity, and even mental retardation.

Elevated amounts of lead in the environment are harmful to plants and crop growth. Neurological effects are observed in vertebrates and animals in association with high lead levels ( 88 ).

Polycyclic Aromatic Hydrocarbons(PAHs)

The distribution of PAHs is ubiquitous in the environment, as the atmosphere is the most important means of their dispersal. They are found in coal and in tar sediments. Moreover, they are generated through incomplete combustion of organic matter as in the cases of forest fires, incineration, and engines ( 89 ). PAH compounds, such as benzopyrene, acenaphthylene, anthracene, and fluoranthene are recognized as toxic, mutagenic, and carcinogenic substances. They are an important risk factor for lung cancer ( 89 ).

Volatile Organic Compounds(VOCs)

Volatile organic compounds (VOCs), such as toluene, benzene, ethylbenzene, and xylene ( 90 ), have been found to be associated with cancer in humans ( 91 ). The use of new products and materials has actually resulted in increased concentrations of VOCs. VOCs pollute indoor air ( 90 ) and may have adverse effects on human health ( 91 ). Short-term and long-term adverse effects on human health are observed. VOCs are responsible for indoor air smells. Short-term exposure is found to cause irritation of eyes, nose, throat, and mucosal membranes, while those of long duration exposure include toxic reactions ( 92 ). Predictable assessment of the toxic effects of complex VOC mixtures is difficult to estimate, as these pollutants can have synergic, antagonistic, or indifferent effects ( 91 , 93 ).

Dioxins originate from industrial processes but also come from natural processes, such as forest fires and volcanic eruptions. They accumulate in foods such as meat and dairy products, fish and shellfish, and especially in the fatty tissue of animals ( 94 ).

Short-period exhibition to high dioxin concentrations may result in dark spots and lesions on the skin ( 94 ). Long-term exposure to dioxins can cause developmental problems, impairment of the immune, endocrine and nervous systems, reproductive infertility, and cancer ( 94 ).

Without any doubt, fossil fuel consumption is responsible for a sizeable part of air contamination. This contamination may be anthropogenic, as in agricultural and industrial processes or transportation, while contamination from natural sources is also possible. Interestingly, it is of note that the air quality standards established through the European Air Quality Directive are somewhat looser than the WHO guidelines, which are stricter ( 95 ).

Effect of Air Pollution on Health

The most common air pollutants are ground-level ozone and Particulates Matter (PM). Air pollution is distinguished into two main types:

Outdoor pollution is the ambient air pollution.

Indoor pollution is the pollution generated by household combustion of fuels.

People exposed to high concentrations of air pollutants experience disease symptoms and states of greater and lesser seriousness. These effects are grouped into short- and long-term effects affecting health.

Susceptible populations that need to be aware of health protection measures include old people, children, and people with diabetes and predisposing heart or lung disease, especially asthma.

As extensively stated previously, according to a recent epidemiological study from Harvard School of Public Health, the relative magnitudes of the short- and long-term effects have not been completely clarified ( 57 ) due to the different epidemiological methodologies and to the exposure errors. New models are proposed for assessing short- and long-term human exposure data more successfully ( 57 ). Thus, in the present section, we report the more common short- and long-term health effects but also general concerns for both types of effects, as these effects are often dependent on environmental conditions, dose, and individual susceptibility.

Short-term effects are temporary and range from simple discomfort, such as irritation of the eyes, nose, skin, throat, wheezing, coughing and chest tightness, and breathing difficulties, to more serious states, such as asthma, pneumonia, bronchitis, and lung and heart problems. Short-term exposure to air pollution can also cause headaches, nausea, and dizziness.

These problems can be aggravated by extended long-term exposure to the pollutants, which is harmful to the neurological, reproductive, and respiratory systems and causes cancer and even, rarely, deaths.

The long-term effects are chronic, lasting for years or the whole life and can even lead to death. Furthermore, the toxicity of several air pollutants may also induce a variety of cancers in the long term ( 96 ).

As stated already, respiratory disorders are closely associated with the inhalation of air pollutants. These pollutants will invade through the airways and will accumulate at the cells. Damage to target cells should be related to the pollutant component involved and its source and dose. Health effects are also closely dependent on country, area, season, and time. An extended exposure duration to the pollutant should incline to long-term health effects in relation also to the above factors.

Particulate Matter (PMs), dust, benzene, and O 3 cause serious damage to the respiratory system ( 97 ). Moreover, there is a supplementary risk in case of existing respiratory disease such as asthma ( 98 ). Long-term effects are more frequent in people with a predisposing disease state. When the trachea is contaminated by pollutants, voice alterations may be remarked after acute exposure. Chronic obstructive pulmonary disease (COPD) may be induced following air pollution, increasing morbidity and mortality ( 99 ). Long-term effects from traffic, industrial air pollution, and combustion of fuels are the major factors for COPD risk ( 99 ).

Multiple cardiovascular effects have been observed after exposure to air pollutants ( 100 ). Changes occurred in blood cells after long-term exposure may affect cardiac functionality. Coronary arteriosclerosis was reported following long-term exposure to traffic emissions ( 101 ), while short-term exposure is related to hypertension, stroke, myocardial infracts, and heart insufficiency. Ventricle hypertrophy is reported to occur in humans after long-time exposure to nitrogen oxide (NO 2 ) ( 102 , 103 ).

Neurological effects have been observed in adults and children after extended-term exposure to air pollutants.

Psychological complications, autism, retinopathy, fetal growth, and low birth weight seem to be related to long-term air pollution ( 83 ). The etiologic agent of the neurodegenerative diseases (Alzheimer's and Parkinson's) is not yet known, although it is believed that extended exposure to air pollution seems to be a factor. Specifically, pesticides and metals are cited as etiological factors, together with diet. The mechanisms in the development of neurodegenerative disease include oxidative stress, protein aggregation, inflammation, and mitochondrial impairment in neurons ( 104 ) ( Figure 1 ).

Impact of air pollutants on the brain.

Brain inflammation was observed in dogs living in a highly polluted area in Mexico for a long period ( 105 ). In human adults, markers of systemic inflammation (IL-6 and fibrinogen) were found to be increased as an immediate response to PNC on the IL-6 level, possibly leading to the production of acute-phase proteins ( 106 ). The progression of atherosclerosis and oxidative stress seem to be the mechanisms involved in the neurological disturbances caused by long-term air pollution. Inflammation comes secondary to the oxidative stress and seems to be involved in the impairment of developmental maturation, affecting multiple organs ( 105 , 107 ). Similarly, other factors seem to be involved in the developmental maturation, which define the vulnerability to long-term air pollution. These include birthweight, maternal smoking, genetic background and socioeconomic environment, as well as education level.

However, diet, starting from breast-feeding, is another determinant factor. Diet is the main source of antioxidants, which play a key role in our protection against air pollutants ( 108 ). Antioxidants are free radical scavengers and limit the interaction of free radicals in the brain ( 108 ). Similarly, genetic background may result in a differential susceptibility toward the oxidative stress pathway ( 60 ). For example, antioxidant supplementation with vitamins C and E appears to modulate the effect of ozone in asthmatic children homozygous for the GSTM1 null allele ( 61 ). Inflammatory cytokines released in the periphery (e.g., respiratory epithelia) upregulate the innate immune Toll-like receptor 2. Such activation and the subsequent events leading to neurodegeneration have recently been observed in lung lavage in mice exposed to ambient Los Angeles (CA, USA) particulate matter ( 61 ). In children, neurodevelopmental morbidities were observed after lead exposure. These children developed aggressive and delinquent behavior, reduced intelligence, learning difficulties, and hyperactivity ( 109 ). No level of lead exposure seems to be “safe,” and the scientific community has asked the Centers for Disease Control and Prevention (CDC) to reduce the current screening guideline of 10 μg/dl ( 109 ).

It is important to state that impact on the immune system, causing dysfunction and neuroinflammation ( 104 ), is related to poor air quality. Yet, increases in serum levels of immunoglobulins (IgA, IgM) and the complement component C3 are observed ( 106 ). Another issue is that antigen presentation is affected by air pollutants, as there is an upregulation of costimulatory molecules such as CD80 and CD86 on macrophages ( 110 ).

As is known, skin is our shield against ultraviolet radiation (UVR) and other pollutants, as it is the most exterior layer of our body. Traffic-related pollutants, such as PAHs, VOCs, oxides, and PM, may cause pigmented spots on our skin ( 111 ). On the one hand, as already stated, when pollutants penetrate through the skin or are inhaled, damage to the organs is observed, as some of these pollutants are mutagenic and carcinogenic, and, specifically, they affect the liver and lung. On the other hand, air pollutants (and those in the troposphere) reduce the adverse effects of ultraviolet radiation UVR in polluted urban areas ( 111 ). Air pollutants absorbed by the human skin may contribute to skin aging, psoriasis, acne, urticaria, eczema, and atopic dermatitis ( 111 ), usually caused by exposure to oxides and photochemical smoke ( 111 ). Exposure to PM and cigarette smoking act as skin-aging agents, causing spots, dyschromia, and wrinkles. Lastly, pollutants have been associated with skin cancer ( 111 ).

Higher morbidity is reported to fetuses and children when exposed to the above dangers. Impairment in fetal growth, low birth weight, and autism have been reported ( 112 ).

Another exterior organ that may be affected is the eye. Contamination usually comes from suspended pollutants and may result in asymptomatic eye outcomes, irritation ( 112 ), retinopathy, or dry eye syndrome ( 113 , 114 ).

Environmental Impact of Air Pollution

Air pollution is harming not only human health but also the environment ( 115 ) in which we live. The most important environmental effects are as follows.

Acid rain is wet (rain, fog, snow) or dry (particulates and gas) precipitation containing toxic amounts of nitric and sulfuric acids. They are able to acidify the water and soil environments, damage trees and plantations, and even damage buildings and outdoor sculptures, constructions, and statues.

Haze is produced when fine particles are dispersed in the air and reduce the transparency of the atmosphere. It is caused by gas emissions in the air coming from industrial facilities, power plants, automobiles, and trucks.

Ozone , as discussed previously, occurs both at ground level and in the upper level (stratosphere) of the Earth's atmosphere. Stratospheric ozone is protecting us from the Sun's harmful ultraviolet (UV) rays. In contrast, ground-level ozone is harmful to human health and is a pollutant. Unfortunately, stratospheric ozone is gradually damaged by ozone-depleting substances (i.e., chemicals, pesticides, and aerosols). If this protecting stratospheric ozone layer is thinned, then UV radiation can reach our Earth, with harmful effects for human life (skin cancer) ( 116 ) and crops ( 117 ). In plants, ozone penetrates through the stomata, inducing them to close, which blocks CO 2 transfer and induces a reduction in photosynthesis ( 118 ).

Global climate change is an important issue that concerns mankind. As is known, the “greenhouse effect” keeps the Earth's temperature stable. Unhappily, anthropogenic activities have destroyed this protecting temperature effect by producing large amounts of greenhouse gases, and global warming is mounting, with harmful effects on human health, animals, forests, wildlife, agriculture, and the water environment. A report states that global warming is adding to the health risks of poor people ( 119 ).

People living in poorly constructed buildings in warm-climate countries are at high risk for heat-related health problems as temperatures mount ( 119 ).

Wildlife is burdened by toxic pollutants coming from the air, soil, or the water ecosystem and, in this way, animals can develop health problems when exposed to high levels of pollutants. Reproductive failure and birth effects have been reported.

Eutrophication is occurring when elevated concentrations of nutrients (especially nitrogen) stimulate the blooming of aquatic algae, which can cause a disequilibration in the diversity of fish and their deaths.

Without a doubt, there is a critical concentration of pollution that an ecosystem can tolerate without being destroyed, which is associated with the ecosystem's capacity to neutralize acidity. The Canada Acid Rain Program established this load at 20 kg/ha/yr ( 120 ).

Hence, air pollution has deleterious effects on both soil and water ( 121 ). Concerning PM as an air pollutant, its impact on crop yield and food productivity has been reported. Its impact on watery bodies is associated with the survival of living organisms and fishes and their productivity potential ( 121 ).

An impairment in photosynthetic rhythm and metabolism is observed in plants exposed to the effects of ozone ( 121 ).

Sulfur and nitrogen oxides are involved in the formation of acid rain and are harmful to plants and marine organisms.

Last but not least, as mentioned above, the toxicity associated with lead and other metals is the main threat to our ecosystems (air, water, and soil) and living creatures ( 121 ).

In 2018, during the first WHO Global Conference on Air Pollution and Health, the WHO's General Director, Dr. Tedros Adhanom Ghebreyesus, called air pollution a “silent public health emergency” and “the new tobacco” ( 122 ).

Undoubtedly, children are particularly vulnerable to air pollution, especially during their development. Air pollution has adverse effects on our lives in many different respects.

Diseases associated with air pollution have not only an important economic impact but also a societal impact due to absences from productive work and school.

Despite the difficulty of eradicating the problem of anthropogenic environmental pollution, a successful solution could be envisaged as a tight collaboration of authorities, bodies, and doctors to regularize the situation. Governments should spread sufficient information and educate people and should involve professionals in these issues so as to control the emergence of the problem successfully.

Technologies to reduce air pollution at the source must be established and should be used in all industries and power plants. The Kyoto Protocol of 1997 set as a major target the reduction of GHG emissions to below 5% by 2012 ( 123 ). This was followed by the Copenhagen summit, 2009 ( 124 ), and then the Durban summit of 2011 ( 125 ), where it was decided to keep to the same line of action. The Kyoto protocol and the subsequent ones were ratified by many countries. Among the pioneers who adopted this important protocol for the world's environmental and climate “health” was China ( 3 ). As is known, China is a fast-developing economy and its GDP (Gross Domestic Product) is expected to be very high by 2050, which is defined as the year of dissolution of the protocol for the decrease in gas emissions.

A more recent international agreement of crucial importance for climate change is the Paris Agreement of 2015, issued by the UNFCCC (United Nations Climate Change Committee). This latest agreement was ratified by a plethora of UN (United Nations) countries as well as the countries of the European Union ( 126 ). In this vein, parties should promote actions and measures to enhance numerous aspects around the subject. Boosting education, training, public awareness, and public participation are some of the relevant actions for maximizing the opportunities to achieve the targets and goals on the crucial matter of climate change and environmental pollution ( 126 ). Without any doubt, technological improvements makes our world easier and it seems difficult to reduce the harmful impact caused by gas emissions, we could limit its use by seeking reliable approaches.

Synopsizing, a global prevention policy should be designed in order to combat anthropogenic air pollution as a complement to the correct handling of the adverse health effects associated with air pollution. Sustainable development practices should be applied, together with information coming from research in order to handle the problem effectively.

At this point, international cooperation in terms of research, development, administration policy, monitoring, and politics is vital for effective pollution control. Legislation concerning air pollution must be aligned and updated, and policy makers should propose the design of a powerful tool of environmental and health protection. As a result, the main proposal of this essay is that we should focus on fostering local structures to promote experience and practice and extrapolate these to the international level through developing effective policies for sustainable management of ecosystems.

Author Contributions

All authors listed have made a substantial, direct and intellectual contribution to the work, and approved it for publication.

Conflict of Interest

IM is employed by the company Delphis S.A. The remaining authors declare that the present review paper was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

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Essay on Pollution Crisis in Urban Areas

August 29, 2021 by Sandeep

The presence of poisonous, contaminating substances in the environment around us creates havoc to the dwelling space and introduces harmful and non-biodegradable substances. These harmful chemical-laden toxic elements cause ‘pollution.’ Below, we have provided pollution crisis in urban areas essay, suitable for aspirants preparing for competitive exams.

Urbanisation and Pollution

Man and his ways have polluted the environment around us; it’s a phenomenon prevailing since many millions of years and has reached alarming levels today. The concern in the urban areas is more severe because the greenery belt in the metros cities is severely low, and pollution levels are very high. There is no control on pollution and no scientific checks that can solidly create a lasting impact to decrease pollution levels.

Urban areas have a higher density of vehicles, more emissions from factories and industries, a higher rate of food adulteration, etc. This has caused an overall rise in the average temperatures, created a way for global warming. Due to this, people are suffering from deadly diseases, like cancer and asthma, acid rains are becoming more common. Air, water, land pollution is fully contaminating the environment around us severely.

Burning of Farm Residues

Whenever we take a long drive towards the out suits of any city, we can find thick and thin piles of smoke swelling up from small or big farmlands. It could be paddy straws that are being burnt or any other agricultural leftovers. They cause major reasons for pollution . They can be detrimental to our health too. They have very high small micro-level particles that can choke our lungs and trouble the respiratory system. The concentration of these fine particles in the residue burning would be so high that the smoke can enter the nearby, immediate urban landscape and cause huge damage to the lungs.

Very high levels of toxic elements like nitrogen, phosphorus, etc., are found in this kind of smoke emitting residue burning. The levels of potassium and sulphur can act upon the neighbouring lands and destroy the top layers of the soil. Thus even fertile lands can become barren and unfit for cultivation. This issue could be circled under the group of soil pollution.

The Air Act of 1981 considers burning crops and farm residues an unacceptable and punishable act and can be tried under a judicial lens. But strict enforcement of laws by authorities at the grassroots level is almost absent, making it easy for farmers to continue with their unscientific acts. A simple remedy to this burning issue could be to find alternate rises of farm residues to avoid burning them.

Indian Transportation of Pollution

As chocolates are to children, so is motor pollution to vehicles plying on Indian roads, especially city and urban areas. The environment is degraded by pollutants emitted out from the fumes of exhausts fitted to vehicles. They have ill effects on plant life, animal life and destroy the delicate balance present in the ecosystem. The motor or vehicular pollutants include carbon monoxide, toxic nitrogen oxide, ammonia, high hydrogen, and sulphur dioxide levels. Economic liberation in urban areas has made people more outgoing in their choices of vehicles.

A small family of four now has all four members having four different vehicles to use. It is not about necessity; it is a question of luxury. So the amount of pollution previously caused by a family vehicle has proportionately increased to nearly four-fold. The term ‘car pollution’ is commonly used in urban areas for obvious reasons. The greenhouse emissions can cause a lot of destruction to our atmosphere.

Petrol and diesel, when burnt, release harmful by-products into the environment. The smoke released from cars contains a huge list of pollutants. Particulate matter can choke our lungs and lead to deadly diseases like cancer. The fuel that silently escapes fuel tanks in vehicles is very toxic. They can silently deplete the protective layers of the atmosphere and add to the greenhouse effect.

Better Management of Resources

The primary and most prominent form of pollution in urban areas that reduces the green belt and improves specific contamination is air pollution . We cannot just blame vehicles for pollution. In our day-to-day lives, we depend on plastic items for almost every other need.

We have plastic toothbrushes, plastic mugs, plastic pens, etc. Our whole life revolves around plastic usage! Plastic, after being thrown, does not decay and can cause major health hazards that can’t be cured. Every year along big seashores, we find whales falling dead on the shore with a stomach filled with tons of plastic. So plastic is not a good choice, and we can replace it with other alternatives.

When we step outside our rooms, we forget to turn off lights and fans, leading to energy wastage. Every house, be it in urban or rural background, churns out piles of waste from their homes every day. A scientific way of waste disposal could end soil pollution and attract better ways of handling and treating waste and disposed of resources.

Paper can be recycled, but plastic cannot be recycled. So we can replace our plastic bags and use paper bags in their place. We have to ensure the safe disposal of paints, varnishes, worn-out batteries. Not disposing of them could pollute the air in the immediate environment/neighbourhood and cause further pollution.

Pollution and Loss to National Income

As we begin to put more things into our wardrobe, we should also consciously understand that we are adding to the heap of pollutants around us. When we don’t recycle items and litter our places, we congest our environment and degrade the quality of life. We cause pollution to the air and water sources. Industrial pollution adds debris and creates more havoc than we think. For every such pollution activity, there are associated costs that escalate now and then.

The costs associated with pollution are not directly assessed when a country’s GDP is taken into account. Yet, if we go by relative figures, we can see the same reflected in our national income. Take a simple example: every tourist who visited the sacred Ganges at Varanasi polluted or contributed to pollution. It could be plastic wastes or contaminating water sources.

When all this piled up and was no longer tolerable, the action was essential, and thus it took thousands of crores to clean up the river. This comes from the taxpayer’s money. With every such source of pollution at various other points, national income is seriously affected by pollution factors. Environmental woes add to the problem of pollution plus eat up into the taxpayer’s money since huge sums of relief funds need to be necessitated for welfare activities. Citizens charters have risen to bring about awareness, and we as responsible citizens should stop tolerating this menace.

International Reputation

Pollution, filth, and dirt are common sights when we visit public places in urban areas. Be its railway stations, airports, or bus stands, awareness and consciousness regarding cleanliness are less. When international delegates visit our country to explore business possibilities, they fight for space and greenery in a contaminated and germ-laden atmosphere. So, often the name we achieve in an international scene gets clutched and results in poor remarks in international arenas due to pollution and environmental degradation.

Threat of Diseases

Paying a casual visit to a nearby slum area will give you glaring images of filth, uncleared garbage, poor sanitation facilities, and above all, the spring of diseases and the thriving of life risky viruses and bacteria. Pollution can cause many deadly diseases to both humans and animals. Bronchitis and asthma are becoming common ailments in cities. Not just the older people, even younger generations are falling prey to it.

Smoking is a very normal activity in public places in cities. Smoking can cause cancer of the lungs. The onset of respiratory disease is mainly due to high levels of pollution in cities. Water-borne contaminants can easily cause cholera and diphtheria. Dysentery is a common problem in children when accidentally fed with polluted water. The sewage water mixed with good, potable water can cause mutations to genes and alter the specific creation of progeny in human beings.

Not just that, the high levels of adulterants and toxic minerals and chemicals present in the food we eat can cause gastrointestinal disorders and give way to incurable diseases. Mutations causing cancer are one of the most common things we get to hear, and the loss of lives due to pollution is undoubtedly on a steady rise.

WHO Reports

Some of the recent reports cited, formulated, and land out to the Indian public have shortlisted cities with very high pollution levels and threaten the people living there. Gwalior is one of those prominent cities where levels of air pollution are just unacceptable. The WHO also prescribes safety levels and permissible levels of air pollution. Cities like Delhi are much higher than these permissible levels. The cause of such high levels of toxic pollution can be attributed to a rich concentration of particulate matter.

The Kashmir region and neighbouring Himalayan states are also slowly creeping into the list, given their shift from slow pollution to high contamination levels in air matter. Global reports published by WHO every year collect research data from nearly thousands of Indian cities, say around 3000 and more, and then come up with the final list of most polluted cities. The Indian government has also set up committees to act upon this data and monitor pollution.

Ranking of Indian Cities

It is strange to find many Indian cities making their way into the world’s most polluted cities. The numbers are not just ones or twos; they have a major share in terms of pollution. Gwalior leads the list, followed by Allahabad, Patna, and Raipur. Delhi comes a close next. The power plants and industries in these cities contribute maximum to pollution.

All three categories of pollution – air, water, and land were taken into account while listing cities for pollution. Severe health issues and more effective laws to curb pollution in these cities are called for to enforce norms. Environmental degradation and the eruption of health hazards are some of the other threats and risks that can be expected due to pollution.

Essay on Pollution in Cities

Students are often asked to write an essay on Pollution in Cities in their schools and colleges. And if you’re also looking for the same, we have created 100-word, 250-word, and 500-word essays on the topic.

Let’s take a look…

100 Words Essay on Pollution in Cities

Introduction.

Pollution in cities is a major concern worldwide. It affects our health and environment, making city life challenging.

Types of Pollution

Cities face various types of pollution like air, water, noise, and land. Cars, factories, and waste contribute to this problem.

Effects of Pollution

Pollution harms our health, causing diseases like asthma. It also affects plants, animals, and our climate.

We can reduce pollution by using public transport, recycling, and planting trees. Governments should also enforce strict pollution control laws.

If we all act responsibly, we can reduce pollution and make our cities cleaner and healthier.

250 Words Essay on Pollution in Cities

Pollution in cities has emerged as a significant concern, causing detrimental effects on both human health and the environment. Rapid urbanization, industrialization, and overpopulation have exacerbated the issue, making it a pressing challenge for the modern world.

The Root Causes

The primary sources of urban pollution consist of vehicular emissions, industrial waste, and improper waste disposal. The rising number of vehicles in cities contributes significantly to air pollution, releasing harmful gases such as carbon monoxide and nitrogen oxides. Industrial units, on the other hand, discharge toxic effluents into water bodies, causing water pollution. In addition, the lack of effective waste management systems results in the accumulation of solid waste, leading to soil pollution.

Health and Environmental Impacts

The adverse health effects of urban pollution are alarming. Exposure to polluted air can lead to respiratory disorders, cardiovascular diseases, and even cancer. Water pollution, meanwhile, can cause waterborne diseases and disrupt aquatic ecosystems. Soil pollution affects agricultural productivity and can lead to food contamination.

In conclusion, pollution in cities is a multifaceted issue that requires comprehensive strategies for mitigation. This includes promoting sustainable transportation, implementing stringent regulations on industrial waste, and improving waste management systems. Collective efforts from governments, industries, and individuals are crucial to combat this urban menace and ensure a healthier and safer environment for future generations.

500 Words Essay on Pollution in Cities

Urban pollution is a critical issue that has been escalating at an alarming rate. Cities, being the epicenters of human civilization, industrialization, and modernization, are grappling with numerous pollution-related challenges. The severity of pollution in cities is a result of various factors, including rapid urbanization, increased industrial activities, and population growth.

The Nature of Urban Pollution

Urban pollution manifests in different forms, the most notable being air, water, and land pollution. Air pollution primarily results from the emission of harmful gases from industries, vehicles, and power plants. These pollutants, including carbon dioxide, sulfur dioxide, and nitrogen oxides, contribute to global warming and cause health problems like asthma, lung diseases, and even cancer.

Water pollution in cities is often due to the improper disposal of industrial waste into water bodies, leading to their contamination. This pollution not only affects aquatic life but also poses a significant risk to human health when contaminated water is used for consumption or irrigation. Land pollution, on the other hand, is mainly due to improper waste management, leading to the accumulation of solid waste, which can contaminate the soil and groundwater.

The Impact of Urban Pollution

The impacts of pollution in cities are far-reaching and multifaceted. On a health level, exposure to pollutants can lead to a myriad of diseases and health complications, ranging from respiratory problems to cardiovascular diseases. Economically, pollution can lead to decreased productivity due to health-related work absences and increased healthcare costs.

Furthermore, pollution affects the urban ecosystem, leading to biodiversity loss. For example, water pollution can lead to the death of aquatic life, while air pollution can affect bird populations by altering their habitats. The aesthetic value of cities also decreases due to pollution, as littered streets, polluted rivers, and smog-filled skies are not appealing sights.

Addressing Urban Pollution

Addressing urban pollution necessitates a multi-pronged approach. Regulatory measures, such as enforcing strict emission standards for industries and vehicles, can help reduce air pollution. Improved waste management systems can help mitigate land pollution, while stricter regulations on waste disposal can help curb water pollution.

Public awareness and education are also crucial in combatting urban pollution. People need to understand the impacts of their actions on the environment and be encouraged to adopt greener lifestyles. Technological innovations, such as renewable energy sources, electric vehicles, and sustainable waste management solutions, can also play a vital role in mitigating urban pollution.

In conclusion, pollution in cities is a pressing issue that needs immediate attention and action. While the problem is complex and multifaceted, it is not insurmountable. Through a combination of regulatory measures, public awareness, and technological innovations, we can significantly reduce pollution in our cities and create healthier, more sustainable urban environments.

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Introductory essay

Written by the educators who created Ecofying Cities, a brief look at the key facts, tough questions and big ideas in their field. Begin this TED Study with a fascinating read that gives context and clarity to the material.

Right now, our economy operates as Paul Hawken said, "by stealing the future, selling it in the present and calling it GDP." And if we have another eight billion or seven billion people, living on a planet where their cities also steal the future, we're going to run out of future really fast. But if we think differently, I think that, in fact, we can have cities that are not only zero emissions, but have unlimited possibilities as well. Alex Steffen

The urgency of urban planning today

Within a few decades' time, we can expect the planet to become more crowded, resources more precious, and innovative urban planners increasingly important. By midcentury, the global population will likely top nine billion, and more than half will live in cities. What will these cities look like? Will we have the resources to power them and comfortably provide for their residents? Will global urbanization harmonize with efforts to curb climate change and secure a sustainable future, or are these forces hurtling towards a head-on collision?

The TED speakers featured in Ecofying Cities underscore the urgency, but also suggest that some optimism's in order as they outline the issues and offer imaginative solutions.

There's no single reason for or response to the complex environmental, economic and social challenges that are part of our future in cities. They call for multiple approaches, originating from different sources — individuals, communities, governments, businesses — and deployed at different levels — in the home, the neighborhood, the city, region, nation and across the globe — to respond to the challenges at hand. As Alex Steffen reminds the urban planners, architects, designers, elected leaders and others involved in the effort, "All those cities are opportunities."

Urbanism and the environment: A brief history

For centuries, successful city-building has required careful attention to the environmental consequences of urban development. Without this, as Jared Diamond demonstrated in Collapse: How Societies Choose to Fail or Succeed , a city inevitably ended up fouling its nest, thus entering a spiral of epidemics, economic hardship, decline and, ultimately, oblivion. Civilizations evolved different ways of dealing with environmental considerations — some with more success than others. For example, thanks to elaborate aqueducts and sewer systems, the Romans were able to build and sustain for centuries large cities that featured a reliable public water supply and state-of-the-art public health conditions.

In other civilizations, however, residents simply abandoned cities when they could no longer rely on their environment to supply the resources they needed. Often this was a direct result of their own activities: for example, deforestation and the attendant erosion of fertile soil, epidemics due to contaminated water and, with the advent of coal-fired industrialization, air pollution.

Urban planning got its start as a profession largely dedicated to averting different types of crises arising from urban growth and providing conditions for public health. This was particularly true in the many 19th century European and North American cities transformed by industrialization and unprecedented rates of population growth. Rapidly deteriorating air and water quality made it necessary to introduce regulations to protect the health of the residents of these cities.

The planners' first-generation improvements included sewers, water treatment and distribution, and improved air quality through building codes and increased urban green space. It's especially remarkable today to think that these interventions were adopted in response to observable health consequences, but without knowledge of the contamination mechanisms at work: germ theory didn't arrive on the scene until Louis Pasteur published his work in the 1860s. From the late 19th century onward Pasteur's findings bolstered the case for even more urban sanitation improvements, particularly those designed to improve water quality.

Starting in the 1950s, however, planners no longer narrowly targeted immediate health effects on urban residents as their chief environmental concern. Their work also absorbed and reflected Western society's deeper understanding of, and respect for, natural processes and growing awareness of the long-term environmental impacts of cities from the local to the planetary scale.

Rachel Carson is often credited as the first to popularize environmentalism. Published in 1962, her landmark book Silent Spring sounded a warning call about how pesticides endanger birds and entire ecological systems. Soon after, air pollution became a rallying point for environmentalists, as did the loss of large tracks of rural and natural land to accelerated, sprawling development. Today, sustainable development and smart growth, which largely overlap and address multiple environmental considerations, enjoy wide currency; most urban planning is now based on these principles.

Today, as we reckon with population growth, advancing rates of urbanization, and widespread recognition of climate change, we know that the cities of the future share a common destiny. The choices we make about how we build, inhabit and maintain these cities will have global and long-term effects.

Sustainable development: Two schools of thought

In modern urban planning, there are two general categories of sustainable development. The first doesn't challenge the present dynamics of the city, allowing them to remain largely low-density and automobile-oriented, but still makes them the object of measures aimed to reduce their environmental load (for example, green construction practices). Ian McHarg spearheaded this approach as a way to develop urban areas in harmony with natural systems; the planning principles he formulated gave special care to the preservation of water and green space. His lasting influence is visible in many of the more enlightened suburban developments of recent decades which respect the integrity of natural systems. Today, the Landscape Urbanism movement promotes these same ideas.

A second school of urban development focuses on increasing urban density and reducing reliance on the automobile. This approach advocates transit-oriented and mixed-use development along pedestrian-friendly "complete streets." On a regional scale, it aims to reduce sprawl by creating a network of higher-density multifunctional centers interconnected by public transit. Today, it's common for plans with a metropolitan scope to follow this approach.

Studying the city: About these materials

Cities are arguably the most complex human creation (with the possible exception of language) so it's not surprising that we study them at multiple scales and from diverse perspectives. We can approach cities through a narrow focus on an individual building or a neighborhood, expand the investigation to consider a metropolitan region in its entirety, or study the global system of cities and its interconnections. What's more, we can think about cities as built environments, social networks, modified ecologies, economic systems and political entities. Aware of the multiple ways that we engage with cities, the Romans had two words to refer to them: urbs referred to the physical city with its wall and buildings, and civitas , the city as a collection of residents.

Ecofying Cities explores urban areas at different scales. In some cases, the TED speaker focuses on a neighborhood project, like The High Line in Manhattan; others describe city-wide transformation, as in Curitiba, Brazil, or a regional or national initiative like China's plan for a network of eco-cities to house its growing urban population. Likewise, the talks explore cities from different disciplinary perspectives including urban planning, urban design, transportation planning, architecture, community organization and environmental science. What unites them all? A commitment to sustainability and a belief that sustainability is more about creating positive effects rather than reducing negative impacts.

The message emanating from Ecofying Cities is one of complexity, optimism and uncertainty. We can't be sure that the changes these speakers suggest will be enough to help us balance supply and demand in the sustainability equation. But we can expect that their ideas and efforts will improve the built environment — as well as quality of life — in cities, thereby providing hopeful perspectives for a sustainable future.

Let´s begin with writer and futurist Alex Steffen´s TEDTalk "The Sharable Future of Cities" for a look at the interplay between increasing urban density and energy consumption.

Alex Steffen

The shareable future of cities, relevant talks.

Jaime Lerner

A song of the city.

Majora Carter

Greening the ghetto.

Robert Hammond

Building a park in the sky.

Michael Pawlyn

Using nature's genius in architecture.

William McDonough

Cradle to cradle design.

James Howard Kunstler

The ghastly tragedy of the suburbs.

Ellen Dunham-Jones

Retrofitting suburbia.

Essay on Pollution Due to Urbanisation

Urbanization refers to the process of increasing population and industrialization in urban areas. As cities continue to grow and expand, pollution caused by urbanization has become a significant environmental concern. Urbanization leads to increased pollution in many forms, including air pollution, water pollution, and noise pollution.

Air pollution is one of the most significant environmental problems caused by urbanization. Urban areas typically have a high concentration of vehicles, industry, and power plants, all of which are major sources of air pollution. The burning of fossil fuels, such as coal and oil, releases harmful pollutants, including particulate matter, sulfur dioxide, and nitrogen oxides, into the air. These pollutants can have a range of negative health effects, including respiratory and cardiovascular diseases. In addition, air pollution can also damage crops and buildings, and contribute to climate change.

Water pollution

Water pollution is another major problem caused by urbanization. Urban areas typically have a high population density, which leads to an increase in the amount of waste and sewage produced. This can lead to the pollution of water sources, including rivers, lakes, and oceans, with harmful chemicals and pollutants. In addition, urbanization can also lead to the destruction of natural habitats, such as wetlands and rivers, which can negatively impact local ecosystems.

Noise pollution

Noise pollution is another environmental problem caused by urbanization. Urban areas typically have a high level of traffic and industrial noise, which can have negative effects on human health and well-being. Noise pollution can cause hearing loss, sleep disturbances, and stress, and can also negatively impact wildlife.

Urbanization also contributes to the destruction of natural habitats and loss of biodiversity. Urban areas often require large amounts of land for development, which leads to the destruction of forests, wetlands, and other natural habitats. This can have a negative impact on local ecosystems and wildlife, and can also contribute to climate change.

Urbanization can also lead to a lack of green spaces and access to nature in urban areas. This can have negative effects on human health and well-being, as well as negatively impacting local ecosystems.

To address the pollution caused by urbanization, there are several actions that can be taken. One approach is to reduce the use of fossil fuels and promote the use of clean energy sources, such as solar and wind power. This can help to reduce air pollution and greenhouse gas emissions. In addition, strict regulations and laws can be implemented to control and minimize pollution from industrial and transportation sources.

Another approach is to promote sustainable urban planning and development. This can include incorporating green spaces and access to nature in urban areas, promoting compact and efficient land use, and encouraging the use of public transportation.

Finally, individuals can also play a role in reducing pollution caused by urbanization by making eco-friendly choices and taking actions such as reducing energy consumption, using public transportation, and recycling.

Urbanization leads to a range of environmental problems, including air pollution, water pollution, noise pollution, loss of biodiversity, and lack of green spaces. To address these problems, a combination of policy measures, urban planning and individual actions are required. These measures include reducing the use of fossil fuels, promoting sustainable urban planning and development, and encouraging individuals to make eco-friendly choices and take actions to reduce pollution. By taking these actions, we can help to reduce the negative impact of urbanization on the environment and improve the health and well-being of both people and the planet.

Urban Pollution – Many Long Years Ago Essay

Urban Pollution – Many Long Years Ago is a masterpiece written by Joel A. Tarr addressing the issue of urban pollution many years ago before the invention of automobile. Tarr also compares pollution caused by automobiles to that caused by horses, putting into consideration the promises that came with automobiles with respect to creating cleaner and safer streets. Finally, Tarr comments on the optimism that people have towards nuclear power plants as substitute to fossil fuels.

By 1970s, Americans were grappling with the reality of automobiles with respect to urban pollution with many claiming that it would be better if horses were still used as form of transport. However, though unknown to many people, horses caused the same pollution problems that automobiles were causing at that time.

As early as the 14 th century, people were decrying foul due to sanitation problems caused by horses. According to Tarr, by 1907, some cities like Milwaukee had a population of 12,500 horses translating to 133 tons of manure daily (13). This manure offered rich breeding grounds for flies, which are disease carriers.

The great number of horses in the streets of American cities caused air pollution. Combination of hay, harness oil, urine and manure produced a strong stench making the streets filthy. Swarms of flies were all over. Ironically, steam engine did not replace horse transportation because horses had to ferry people to and from their residential areas.

Dwellers of American cities around this time were constantly faced with the challenge of cleaning streets of horse manure and urine putrefaction. This forced authorities in New York and Boston to set aside money to facilitate cleaning of streets.

Fear of disease drove many urban residents to come together, backed with the authorities to clean streets to “divest the city of that foul aliment on which the pestilence delights to feed” (Tarr 15). Typhoid, small pox, and cholera among other diseases emanated from these filthy conditions in the streets. Nevertheless, in the mid nineteenth century, these efforts were scuttled by corruption and reluctance to engage in this unsatisfying task.

Noise pollution was also rampant from clopping iron horse shoes to clanking wagon wheels. This led to banning of horse drawn wagons in some cities to avoid interfering with important matters like deliberations of General Court. The scene of horses in streets was also disturbing to the eye given that many were drudges spending the whole day being overburdened.

This led to death of many along the streets and as they putrefied, they added another problem to urban pollution. Others broke their legs and lied by the streets to nurse their wounds making the scenery pathetic.

Then the automobiles came as people ushered in the twentieth century. Optimism was high hoping that elimination of horses from the streets would create a safer and cleaner environment with automobiles offering this antidote.

Eventually, many cities banned use of horses from their streets giving way to automobiles. This move came with not only efficiency and time saving, but also with its setbacks. It did not take long for people to realize that noise pollution from automobiles was more than that of horses and wagons. Automobile emissions nettle eyes and causes lung infections just like horse manure.

Automobiles are causing greater environmental challenges that will soon dwarf those emanating from horses if unchecked. Nuclear electricity looks promising but the repercussions may be far reaching. To recap this, automobiles cause urban pollution just like horses; moreover, nuclear electricity will come with its demerits, urban pollution is here to stay.

Works Cited

Tarr, Joel. “Urban Pollution – Many Years Ago.” American Heritage. New York: American Heritage Publishing Co. 1971.

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IvyPanda. (2018, June 28). Urban Pollution - Many Long Years Ago. https://ivypanda.com/essays/urban-pollution-many-long-years-ago/

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Essay on Pollution for Students and Children

500+ words essay on pollution.

Pollution is a term which even kids are aware of these days. It has become so common that almost everyone acknowledges the fact that pollution is rising continuously. The term ‘pollution’ means the manifestation of any unsolicited foreign substance in something. When we talk about pollution on earth, we refer to the contamination that is happening of the natural resources by various pollutants . All this is mainly caused by human activities which harm the environment in ways more than one. Therefore, an urgent need has arisen to tackle this issue straightaway. That is to say, pollution is damaging our earth severely and we need to realize its effects and prevent this damage. In this essay on pollution, we will see what are the effects of pollution and how to reduce it.

Effects of Pollution

Pollution affects the quality of life more than one can imagine. It works in mysterious ways, sometimes which cannot be seen by the naked eye. However, it is very much present in the environment. For instance, you might not be able to see the natural gases present in the air, but they are still there. Similarly, the pollutants which are messing up the air and increasing the levels of carbon dioxide is very dangerous for humans. Increased level of carbon dioxide will lead to global warming .

Further, the water is polluted in the name of industrial development, religious practices and more will cause a shortage of drinking water. Without water, human life is not possible. Moreover, the way waste is dumped on the land eventually ends up in the soil and turns toxic. If land pollution keeps on happening at this rate, we won’t have fertile soil to grow our crops on. Therefore, serious measures must be taken to reduce pollution to the core.

Get English Important Questions here

Types of Pollution

• Air Pollution
• Water Pollution
• Soil Pollution

How to Reduce Pollution?

After learning the harmful effects of pollution, one must get on the task of preventing or reducing pollution as soon as possible. To reduce air pollution, people should take public transport or carpool to reduce vehicular smoke. While it may be hard, avoiding firecrackers at festivals and celebrations can also cut down on air and noise pollution. Above all, we must adopt the habit of recycling. All the used plastic ends up in the oceans and land, which pollutes them.

So, remember to not dispose of them off after use, rather reuse them as long as you can. We must also encourage everyone to plant more trees which will absorb the harmful gases and make the air cleaner. When talking on a bigger level, the government must limit the usage of fertilizers to maintain the soil’s fertility. In addition, industries must be banned from dumping their waste into oceans and rivers, causing water pollution.

To sum it up, all types of pollution is hazardous and comes with grave consequences. Everyone must take a step towards change ranging from individuals to the industries. As tackling this problem calls for a joint effort, so we must join hands now. Moreover, the innocent lives of animals are being lost because of such human activities. So, all of us must take a stand and become a voice for the unheard in order to make this earth pollution-free.

Get the huge list of more than 500 Essay Topics and Ideas

FAQs on Pollution

Q.1 What are the effects of pollution?

A.1 Pollution essentially affects the quality of human life. It degrades almost everything from the water we drink to the air we breathe. It damages the natural resources needed for a healthy life.

Q.2 How can one reduce pollution?

A.2 We must take individual steps to reduce pollution. People should decompose their waster mindfully, they should plant more trees. Further, one must always recycle what they can and make the earth greener.

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Essay on environmental pollution in urban areas (357 words).

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Here is your essay on environmental pollution in Urban Areas!

An environment is made-up of the circumstances, objects or conditions by which a human, animal, plant or object is surrounded. The term environment’ generally refers to the natural world as perceived by humans.

‘Pollution’ refers to harmful environmental contaminants and to the act or the process of polluting the environment. Generally, the process needs to concern human activity, which results in pollution. Even relatively benign products of human activity are liable to be regarded as pollution, if they precipitate negative effects later on.

Image Courtesy : upload.wikimedia.org/wikipedia/commons/7/7c/Litter.JPG

The Environmental Protection Agency (EPA) defines pollution as ‘the presence of a substance in the environment that because of its chemical composition or quality prevents the functioning of natural processes and produces undesirable environmental and health effects.’ Any material that causes the pollution is called a ‘pollutant.’

Pollution can be defined according to its contextual efficacy (use). Blooms of algae and the resultant eutrophication (the enrichment of an aquatic system by the addition of nutrients primarily caused by leached phosphorous or nitrogen containing compounds in lakes, rivers, bays or other semi-enclosed waters) of lakes and coastal ocean is con­sidered as pollution, when it is fuelled by the nutrients from industrial, agricultural or residential run-off.

Although carbondioxide (CO 2 ) is not toxic and actually stimulates plant growth but because it is a greenhouse gas that fosters global warming, it is sometimes referred to as pollution. More often and more properly, CO 2 from such sources as combustion of fuels is labelled neutrally as ’emission.’

Traditional forms of pollution include air pollution, water pollution, while a broader interpretation of the word has led to the ideas of ship pollution, light pollution and noise pollution.

Serious pollution sources include chemical plants, oil refineries, nuclear waste dumps, regular garbage dumps (many toxic substances are illegally dumped there), incinerators, PVC factories, corporate animal farms creating huge amounts of animal waste. Some of the more common contaminants are lead (like in lead paint), chromium, zinc, arsenic and benzene.

Pollutants are thought to play a part in a variety of maladies including cancer, lupus, immune diseases, allergies and asthma.

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