Pollution In Cities Research Articles

Soundscape and subjective factors affecting residents' evaluation of aircraft noise in the communities under flight routes.

Aircraft noise is one of the most significant sources of environmental pollution in large cities. During the COVID-19 pandemic, strict lockdown in community might increase residents' discomfort with the noise, which could disrupt public activities and reduce subjective well-being. Most of the existing studies considered aircraft noise as a single sound source, which have ignored the influence of other sounds in the community. This paper applied field survey to identify the soundscape and non-acoustic factors related to aircraft noise evaluation. Paper questionnaires were delivered to select residents of three sample residential areas near Shenzhen Bao'an International Airport to investigate residents' general health, evaluation of aircraft noise, community activities, and attitudinal factors. The relationship between respondent's noise evaluations and subjective factors were investigated through statistical analyses controlling for measured aircraft noise levels and the existence of soundscape facilities. The results indicated that the negative effects of aircraft noise were enhanced during the lock down, especially for frequent space users and those residents in poor health status. Under conditions of similar levels of aircraft noise exposure, communities with more birdsong and fountain sounds had lower proportion of highly annoyed respondents and higher level of soundscape ratings. This paper further indicated that personal factors including fear of air travel, noise sensitivity, and the frequency of outdoor activity had increased the level of annoyance to aircraft noise, while higher degree of annoyance to aircraft noise was associated with poor health status. The findings implied the moderating effects of subjective factors and the restorative effects of natural sounds, which could inform aircraft noise control and community consultation strategies by protecting vulnerable populations and creating community soundscape facilities. Future research might conduct a pre- and post-experiment to estimate the potential causal impact of the soundscape intervention.

Aerosol pollution of the Moscow megacity by polyaromatic hydrocarbons: Seasonal variability and toxicological risks

Research on air pollution in large cities by polycyclic aromatic hydrocarbons (PAHs) is one of the priority tasks for assessing air quality and environmental risks to public health. The chemical composition of aerosols sampled in spring (2018), 2019, and winter (2019–2020) at the Aerosol Complex of Moscow State University, located on the background territory of the Moscow Megacity, is analyzed. Sixteen priority PAH compounds were identified using gas chromatography, mass spectrometry, and high-performance liquid chromatography. The median value of the total concentration of the 16 PAHs (Σ16PAH) increases from the spring season (1.43 ng/m3) to the fall season (1.68 ng/m3) and then to the winter season (2.47 ng/m3). Based on the diagnostic relationships of PAHs, the dominant contribution of transport, industrial enterprises, and the heating system to the total emissions was determined. Pollution roses indicate the location of sources of maximum concentrations of low-, medium-, and high-molecular PAHs. Pollution episodes are distinguished: in the spring of 2018 under the influence of the transport of smoke plumes of agricultural fires and in the fall of 2019 as a result of petrogenic emissions and an increase in biomass burning in the residential sector around Moscow. In the winter and fall seasons, the highest values of carcinogenic (0.45 and 0.42) and mutagenic (0.58 and 0.55) equivalents for benzo(a)pyrene were recorded in comparison with the spring season (0.26 and 0.38). The lifetime risk of developing lung cancer, calculated from the data for three seasons, is 0.5 cases per one million people.

Study of the influence of road traffic emissions on air quality in sensitive areas of the Bucharest city, using Breeze Aermod software

Road traffic is one of the main causes of pollution in big cities due to a large number of vehicles and crowded intersections. Also, the lack of green spaces and the topography of the land can cause the accumulation of pollutants at the local level. Considering the increasing concern regarding the negative impact of air pollution on the health of the inhabitants of large cities, the present paper aims to investigate the level of pollution in the areas of two educational units located near some crowded boulevards in the city of Bucharest. To carry out the work, the air quality was analyzed by in-situ monitoring of the CO, PM10, and NO2, indicators of atmospheric pollution that could come from road traffic. Also were estimate the contribution of the nearest pollution sources to the total concentrations of pollutants measured by air quality monitoring equipment. Although more traffic emission were estimated near of the first monitoring area, than the second monitoring area, still the contribution to local pollution in the case of emission sources from area 2 was higher, this aspect was the cause of the complexity of the terrain, the higher buildings surrounding the emission sources, and the lack of vegetation.

Interpretation of odor complaint records with BTEX pollutants and meteorological factors: Çorlu case study

Air pollution in urban areas increases as a result of emitted air from different sources within the mixing layer of troposphere. Odor pollution is amongst the primary reasons behind environmental nuisance and occurrence of citizen complaints. Frequent exposure to odorous compounds and/or odor nuisance are increasingly associated with air pollution problems. Besides, there is no universally accepted environmental odor management method reported so far. Level of air pollutants emission, distance of emission sources to residential areas, to-pography, geographical and meteorological conditions have influence on imposed level of air pollution and odor pollution in cities.
 
 This study is built on the citizen odor complaint data (based on frequency, intensity, duration, odor tone and location (namely the FIDOL factors) collected in Çorlu/Tekirdağ through the GIS integrated public participated platform, namely the Çorlu KODER mobile application. The annual odor complaint data was briefly introduced and given an evaluation with the mo-bile app users demographic information. The obtained data between August 28-November 2 of 2021, was subjected to interpretative evaluation and statistical analysis with BTEX (benzene, toluene, ethylene benzene and xylen) concentrations, inorganic air pollution concentrations and meteorological factors. In light of the obtained results, temperature, wind speed, relative humidity and toluene concentration were found to play a significant role on the number of citizen odor complaints. The EU reported limit value, lower rating threshold and upper rating threshold for BTEX pollutants have been exceeded several times.
 
 The average Toluene/benzene ratios obtained during the study show that; non-traffic sources contribute significantly to VOC emissions. Air pollutants transportation mechanism from neighbouring OIZ settlements become a prominent justification and support the hypothesis that residential areas of Corlu are under the effect of industrial air pollution and odor pollution con-stituents. There is low level of negative correlation between the benzene measured in Çorlu and WS (r=-0.63). Below 2.4 m/s, the average number of odor complaints (ANOC) tend to increase, while above this level odor complaints are diminished). The ANOC remained around 4 for[C] < 4 ug/m3 and reached to 18 for [C]BTEXtotal > 8 ug/m3. Above [C]Toluen=3 ug/m3 conditions, Daily ANOC increase from 7 to 19. Over [C]Toluen= 4 ug/m3 conditions, it reached up to 23. Increses in the number of daily ANOC by temperature is distinct over 21 C0 and reaches to 35. 
 
 The GIS integrated citizen complaint collection platforms are critical for real-time data collection of environmental complaints with high spatiotemporal accuracy. Citizen odor complaint surveys are useful monitoring tools and obtained data sets can be used to identify sensitive areas where and when specific actions should be taken and air pollutants measuement studies be performed.

Spatial and sector-specific contributions of emissions to ambient air pollution and mortality in European cities: a health impact assessment

Ambient air pollution is a major risk to health and wellbeing in European cities. We aimed to estimate spatial and sector-specific contributions of emissions to ambient air pollution and evaluate the effects of source-specific reductions in pollutants on mortality in European cities to support targeted source-specific actions to address air pollution and promote population health. We conducted a health impact assessment of data from 2015 for 857 European cities to estimate source contributions to annual PM2·5 and NO2 concentrations using the Screening for High Emission Reduction Potentials for Air quality tool. We evaluated contributions from transport, industry, energy, residential, agriculture, shipping, and aviation, other, natural, and external sources. For each city and sector, three spatial levels were considered: contributions from the same city, the rest of the country, and transboundary. Mortality effects were estimated for adult populations (ie, ≥20 years) following standard comparative risk assessment methods to calculate the annual mortality preventable on spatial and sector-specific reductions in PM2·5 and NO2. We observed strong variability in spatial and sectoral contributions among European cities. For PM2·5, the main contributors to mortality were the residential (mean contribution of 22·7% [SD 10·2]) and agricultural (18·0% [7·7]) sectors, followed by industry (13·8% [6·0]), transport (13·5% [5·8]), energy (10·0% [6·4]), and shipping (5·5% [5·7]). For NO2, the main contributor to mortality was transport (48·5% [SD 15·2]), with additional contributions from industry (15·0% [10·8]), energy (14·7% [12·9]), residential (10·3% [5·0]), and shipping (9·7% [12·7]). The mean city contribution to its own air pollution mortality was 13·5% (SD 9·9) for PM2·5 and 34·4% (19·6) for NO2, and contribution increased among cities of largest area (22·3% [12·2] for PM2·5 and 52·2% [19·4] for NO2) and among European capitals (29·9% [12·5] for PM2·5 and 62·7% [14·7] for NO2). We estimated source-specific air pollution health effects at the city level. Our results show strong variability, emphasising the need for local policies and coordinated actions that consider city-level specificities in source contributions. Spanish Ministry of Science and Innovation, State Research Agency, Generalitat de Catalunya, Centro de Investigación Biomédica en red Epidemiología y Salud Pública, and Urban Burden of Disease Estimation for Policy Making 2023-2026 Horizon Europe project.

Assessment Of Air Pollution And Its Association With Population Health: Geo-Statistical Evidence From Pakistan

Human health is harmed by air pollution. The objective of this research was to show that air pollution in Pakistan is getting worse and is negatively impacting people’s health. IQ Air and the Institute for Health Metrics and Evaluation provided the data for this descriptive research. Monthly data of PM2.5 μg/m³ from ten different localities across Pakistan are used to show spatial distribution through the geospatial technique of interpolation. The findings show that two third of the country has high PM2.5 concentration, with Lahore as the most polluted city. In Pakistan, solid fuel use has decreased, leading to a decline in associated mortality and morbidity. However, there have been significant increases in PM2.5 and ozone levels, resulting in a rise in the country’s overall health burden caused by air pollution. Furthermore, the number of deaths attributed to air pollution has also increased since 1990. A total of 57% of chronic obstructive pulmonary disease, 40% of lower respiratory infections, 36% of ischemic stroke, 35% of ischemic heart diseases, 32% of lung cancer, 25% of diabetes, and 20% of neonatal outcomes are directly attributed to air pollution in Pakistan. The main contributors to air pollution are population growth, growing motorization, and unsustainable energy usage. The main challenges due to air pollution control and monitoring in Pakistan include a lack of awareness, poor policy creation and implementation, the use of improper fuel, rising energy demands, and an absence of pollution monitoring stations in most cities. Therefore, there is a need for a robust air pollution monitoring system, increased public awareness, and the implementation of clean and sustainable policies to regulate this environmental health issue.

Pollution Reduction, Informatization and Sustainable Urban Development—Evidence from the Smart City Projects in China

China’s modernization endeavors to advance both material and spiritual civilization concomitantly; nevertheless, the nation presently faces a pressing issue of urban pollution. This research examines how the introduction of information technology has affected environmental pollution in Chinese cities. By utilizing a panel dataset consisting of 214 prefecture-level cities in China spanning from 2005 to 2017, we employed a time-varying DID model with smart city pilot projects serving as a quasi-natural experiment to assess the impact of informatization on environmental pollution. The establishment of smart cities has remarkably elevated the information quotient of urban areas. Additionally, the results indicate a significant reduction in pollution levels in urban areas as a result of informatization, which remained robust even after conducting a series of rigorous tests to ensure the reliability of the findings. Mechanism analysis shows that informatization of smart cities affects the environmental governance behavior of enterprises and governments. Consequently, the implementation of informatization in smart cities can effectively alleviate environmental pollution by means of both the technique effect and structure effect. This finding calls for the Chinese government to improve informatization by promoting smart city pilot projects to build sustainable cities.

Impact analysis of meteorological variables on PM2.5 pollution in the most polluted cities in China

With the continuous promotion of urbanization in China, air pollution problems have become increasingly prominent in recent years. Various factors, such as emissions, meteorology, and physical and chemical reactions, jointly affect the severity of PM2.5 pollution to a large extent. This study selected five meteorological variables (planetary boundary layer height (PBLH), wind speed (WS), temperature(T), water vapor mixing ratio(Q), and precipitation (PCP)) for perturbation, and 21 different scenarios were set up. In this study, the effects of changes in a single meteorological variable on the pollutants produced in the area were represented by subtracting the baseline scenario (i.e., without perturbation of meteorological variables) simulated in January 2017 separately from each post-disturbance scenario. The results showed that Handan (HD) has the highest annual mean PM2.5 concentration of 85.75 μg/m3 in 2017, while all cities in study area exceeded the secondary concentration limit of urban atmospheric particulate matter. The correlation coefficient (R) between the simulation values of models and the actual monitoring values ranges from 0.41 to 0.74, indicating good model performance and acceptable simulation errors. PBLH (±10%-±20%), WS(±10%-±20%), and PCP(±10%-±20%) all showed a single adverse effect among the five meteorological variables, meaning that a reduction in these three factors led to an increase in PM2.5 concentrations. However, T (±1 K-±1.5 K) and Q (±10%-±20%) could indicate a positive impact under certain conditions. From the sensitivity calculations of single meteorological variables, it is clear that WS, PBLH, and PCP show a highly linear trend in all cities at the 0.01 level of significance. The hypothesis that T changes linearly in 10 cities in the study area is valid, while for Q, the hypothesis that Q changes linearly only occurs in Shijiazhuang and Baoding. When different meteorological variables are disturbed, there are significant spatial differences in the main affected areas of PM2.5 concentrations. By discussing the impact of meteorological variable disturbance on air quality in critically polluted cities in China, this study identified the meteorological variables that can substantially affect PM2.5 concentration. The more complex T and Q should be considered when formulating relevant emission measures.

Street-scale dispersion modelling framework of road-traffic derived air pollution in Hanoi, Vietnam

Traffic is an important source of air pollution in Vietnamese cities. The spatio-temporal variation of air pollution derived from traffic is poorly understood. Application of dispersion modelling can help but is hindered by the local scarcity of suitable input data. This study fills the data gap, by establishing a framework employing open-access global data to model emission from traffic activities in Hanoi. The outlined methodology explicitly defines road sources, calculates their emission, and employs background pollution profiles from Copernicus Atmospheric Monitoring Service (CAMS) to produce street-scale distribution maps for CO, PM10 and PM2.5. Pollution hotspots are found near major traffic flows with the highest hourly average CO, PM10 and PM2.5 concentrations at 1206, 87.5 and 61.5 μgm−3, respectively. The relationship between concentrations and properties of the road network is assessed. Motorcycles are the main emitters of the traffic sector. Emission from Heavy Good Vehicles dominate during the night, with contribution percentages increase as it gets further away from the city core. Modelled concentrations are underestimated mainly due to low vehicular emission factor. Adjusting emission factors according to vehicle quality in Vietnam greatly improves agreement. The presence of non-traffic emission sources contributes to the model underestimation. Results for comparisons of daily averaged PM values are broadly in agreement between models and observations; however, diurnal patters are skewed. This results partly from the uncertainties linked with background pollution levels from CAMS, and partly from non-traffic sources which are not accounted for here. Further work is needed to assess the use of CAMS's concentrations in Vietnam. Meteorological input contributes to the temporal disagreement between the model and observations. The impact is most noticeable with CO concentrations during morning traffic rush hours. This study recommends approaches to improve input for future model iterations and encourage applications of dispersion modelling studies in similar economic settings.

Sustainable Traffic Management for Smart Cities Using Internet-of-Things-Oriented Intelligent Transportation Systems (ITS): Challenges and Recommendations

The emergence of smart cities has addressed many critical challenges associated with conventional urbanization worldwide. However, sustainable traffic management in smart cities has received less attention from researchers due to its complex and heterogeneous nature, which directly affects smart cities’ transportation systems. The study aimed at addressing traffic-related issues in smart cities by focusing on establishing a sustainable framework based on the Internet of Things (IoT) and Intelligent Transportation System (ITS) applications. To sustain the management of traffic in smart cities, which is composed of a hybridized stream of human-driven vehicles (HDV) and connected automated vehicles (CAV), a dual approach was employed by considering traffic as either modeling- and analysis-based, or/and the decision-making issues of previous research works. Moreover, the two techniques utilized real-time traffic data, and collected vehicle and road users’ information using AI sensors and ITS-based devices. These data can be processed and transmitted using machine learning algorithms and cloud computing for traffic management, traffic decision-making policies, and documentation for future use. The proposed framework suggests that deploying such systems in smart cities’ transportation could play a significant role in predicting traffic outcomes, traffic forecasting, traffic decongestion, minimizing road users’ lost hours, suggesting alternative routes, and simplifying urban transportation activities for urban dwellers. Also, the proposed integrated framework adopted can address issues related to pollution in smart cities by promoting public transportation and advocating low-carbon emission zones. By implementing these solutions, smart cities can achieve sustainable traffic management and reduce their carbon footprint, making them livable and environmentally friendly.

Whether the Establishment of National High-Tech Zones Can Improve Urban Air Pollution: Empirical Evidence from Prefecture-Level Cities in China

Promoting the construction of national-level high-tech zones as green pioneer zones is a necessary condition for achieving high-quality development. Based on panel data from 254 prefecture-level cities from 2006 to 2018, in this paper, the difference-in-difference (DID) is used to empirically examine the influence effect of the establishment of national high-tech zones on local urban air pollution, and the spatial difference-in-difference (SDID) is used to explore its spatial spillover effect. It was found that the annual average PM2.5 concentration in cities with national high-tech zones decreased by about 1.8% compared with cities without national high-tech zones, and there was a positive spillover effect on the annual average PM2.5 concentration in nearby cities. Industrial structure upgrading and technological innovation effects are two important transmission paths for the establishment of national high-tech zones to influence urban air pollution; the heterogeneity analysis shows that the establishment of national high-tech zones has more significant implications for the improvement of air pollution in non-resource cities and less developed areas in the west, and the air pollution improvement effect of “growing” national high-tech zones is more desirable than that of “mature” national high-tech zones. Our empirical results conclude that we should continue to encourage the promotion of national high-tech zones, optimize the business environment, improve preferential policies, and design a combination of policy instruments scientifically according to local conditions in order to give full play to the effect of national high-tech zones on urban air-pollution improvement.

Solid waste management and urban environmental quality of public space in Chiclayo, Peru

Solid Waste Management (SWM) through planning and technical coordination is essential for the sustainable development of cities in terms of social, physical, territorial, and legal-political aspects. During the last 20 years, Chiclayo has been the most polluted city in northern Peru owing to its poor municipal solid waste (MSW) management. This study aims to determine the level of urban impact generated by SWM on the configuration of public spaces in the districts of José Leonardo Ortiz, La Victoria, and Chiclayo (homonymous district). Management actors were identified with a territorial diagnosis for methodological analysis to obtain efficiency indices. The scope of management in the last ten years was determined using the Fisher-Davies method and Leopold diagrams, and the results obtained were compared with the population's perception. The discussion of the results determined that SWM has a negative level of urban environmental impact on the configuration of public spaces. These have a very negative impact on the biotic and abiotic factors of the urban landscape as well as on sociocultural factors. This study provides evidence of the implications of city governance on territorial sustainability. This will allow for the development of thematic frameworks that address urban, environmental, socioeconomic, and technological policies in response to new territorial dynamics.

Assessing the health impacts of PM2.5 and ozone pollution and their comprehensive correlation in Chinese cities based on extended correlation coefficient

The coordinated control of PM2.5 and ozone pollution is becoming more and more important in the current and next stage of Chinese environmental pollution control. Existing studies are unable to provide sufficient quantitative assessments of the correlation of PM2.5 and ozone pollution to support the coordinated control of the two air pollutants. This study develops a systematic method to comprehensively assess the correlation between PM2.5 and ozone pollution, including the evaluation of the impact of two air pollutants on human health and the extended correlation coefficient (ECC) for assessing the bivariate correlation index of PM2.5-ozone pollution in Chinese cities. According to the latest studies on epidemiology conducted in China, we take cardiovascular and cerebrovascular diseases and respiratory diseases as the ozone pollution’s health burden when evaluating the health impact of ozone pollution. The results show that the health impact of PM2.5 in China decreases by 25.9 % from 2015 to 2021, while the health impact of ozone increases by 11.8 %. The ECC of 335 cities in China shows an increasing-decreasing trend but has generally increased from 2015 to 2021. The study provides important support for an in-depth understanding of the correlation and development trend of Chinese PM2.5 and ozone pollution by classifying the comprehensive PM2.5-ozone correlation performances of Chinese cities into four types. China or other countries will get better environmental benefits by implementing different coordinated management approaches for different correlative types of regions based on the assessment method in this study.

Spatial Analysis of Heavy Metal Pollution in Road-Deposited Sediments Based on the Traffic Intensity of a Megacity

Population growth has led to the intensification of average daily traffic (ADT), highlighting vehicles as one of the major sources of heavy metal (HM) pollution in cities. The objective of this paper is to conduct a spatial analysis of the HM pollution associated with road-deposited sediments (RDSs), based on the ADT observed in the main roads of a Latin American megacity (Bogotá, Colombia). The following risk indices were considered: Geoaccumulation Index (Igeo), Integrated Pollution Index (IPI), Ecological Risk Index (ERI), Comprehensive Potential Ecological Risk Index (CERI), Hazard Index (HI), and Carcinogenic Risk Index (CRI). The findings confirm that a size fraction < 250 μm is the most suitable for studying the risk of HMs in the RDS from the indices considered. The best HMs indicative of the relationship with ADT are Ni, Cu, and Pb. The Pb is the HM of most attention, and Cr gains positions for its toxicity level during the evaluation of ecological, non-carcinogenic, and carcinogenic risks, respectively. Finally, the linear regression models developed between ADT and each of the risk indices considered have a better fit (R2 > 0.910) compared to the linear regression models developed between ADT and HM concentrations (R2 > 0.322).

Spatiotemporal variation of air pollutants and their relationship with land surface temperature in Bengaluru, India

Rapid development and urbanization in most of the cities of the world have led to increased vehicular traffic, industrial activities, and construction. Air pollution in most cities of developing countries, like India, often exceeds the limits given in relevant national/international standards. Rapid urbanization in Bengaluru is causing increased air pollution and land surface temperature (LST). The present study examines the relationship of LST with air pollutants, meteorological parameters, surface indices, and selected urbanization parameters. The study also aims to find out the air pollutant have the maximum effect on LST during different seasons. Air pollutants and meteorological data were collected from air quality monitoring stations, while LST data of MODIS satellite was downloaded from the internet. Data for the period 2018–2022 was utilized for the current research. The results indicated that PM2.5 concentrations exceeded WHO standards, and Hombegowda Nagar (B9), Peenya (B5), and Bapuji Nagar (B4) were identified as pollution hot-spots. A strong association of LST with air pollutants and meteorological parameters was observed during the winter season (R2 = 0.87 to 0.91), which was stronger than the corresponding association during summer (R2 = 0.72 to 0.79). The association further improved after incorporating spectral indices (NDVI and NDBI), global population density (GPD), digital elevation model (DEM), and road line density (RLD) and a very strong association was obtained (R2 value of 0.91 in summer and 0.96 in winter). The study also revealed a strong relationship between the Urban Heat Island index and the combination of all parameters, both for urban and rural areas as well as during both the summer and winter seasons. PM2.5 and SO2 were identified as the main air pollutants affecting LST variations during the summer season, while NO2 and CO were more influential during the winter season. The study concludes that variation in the LST of an area is governed not only by the surface characteristics but it is also affected by air pollutants and meteorological conditions as well as conditions of urbanization that can be represented by different parameters/indices. The findings of this study hold significant implications for future scientific research, and it may pave the way for the integration of effective mitigation strategies to combat the dual challenges of increasing LST and air pollution in urban areas.

Peningkatan Nilai Dissolved Oksigen dan Penetralan pH pada Air Laut Menggunakan Destilasi Sederhana

The issue of water pollution in big cities in Indonesia has shown very concerning signs. This study aims to determine the value of Dissolved Oxygen and pH before and after treatment using distillation. The method is simple experimental design with post test only group control design, carried out in the chemistry laboratory of the Ternate Polytechnic, with sample of 10 liters sea water. The researchers used simple distillation system consisting of electric stove, hose and container filled with cold water. Dissolved Oxygen in seawater samples before treatment did not meet the requirements for class 3 water which based on Government Regulation RI No 22 of 2021 must exceed 3 ppm while the test results showed that Dissolved Oxygen was only 1.7 ppm. dissolved oxygen in seawater samples with distillation treatment has met the requirements for class 3 water which must exceed 3 ppm while the test results show that DO is 6.7 ppm. pH in seawater is still in the category that meets the requirements. pH in seawater after distillation has changed from alkaline to neutral with a test number of 7. In conclusion, distillation is able to increase Dissolved Oxygen and neutralize pH. The recommendation for further research to carry out sampling at several points in order to obtain broader water characteristics, so that it can be used as a reference for decision making at the local government.

Cities of Central Asia: New hotspots of air pollution in the world

Central Asian cities are one of the hotspots for air pollution worldwide. There are limited studies and knowledge regarding air quality variation in this region. This study investigated PM2.5 temporal variations and the influence of meteorological parameters on PM2.5 concentrations for six major cities in Central Asia: Almaty and Astana (Kazakhstan), Ashgabat (Turkmenistan), Bishkek (Kyrgyzstan), Dushanbe (Tajikistan), and Tashkent (Uzbekistan). The results show severe air quality deterioration in the cities with annual PM2.5 concentrations up to ten-fold higher than the limits. A clear seasonal pattern with winter peaks was observed in Almaty, Bishkek, and Astana, whereas winter and summer were highly polluted in Tashkent and Dushanbe. Based on the pollution profiles, cities were classified into several clusters. Episodes with high PM2.5 concentrations were evaluated for regional pollutant transportation using the HYSPLIT model. The results of this investigation highlight a significant discrepancy in official emissions inventory studies. While previous studies have suggested that transportation is the primary source of air pollution, the approach to estimate the share of emission sources was based on an outdated methodology that obscures information on the most hazardous pollutants, including PM2.5. This study shows that coal combustion is the primary source of PM2.5 pollution in most cities, offering policymakers critical insights into the sources of air pollution in the region. These findings demonstrate the need for policymakers to take swift action to address coal use and adopt effective measures to mitigate PM2.5 pollution, thereby improving the health and well-being of the population.

Health risk assessment from exposure to ambient VOCs and particulate matter in different functional zones in Dhanbad, India

This study evaluates the non-cancer risks (NCR) and cancer risks (CR) in outdoor working personnel in Dhanbad city, exposed to volatile organic compounds (VOCs) and particulate matter (PM) present in the ambient air. Dhanbad is known for its coal mines and is one of the most polluted cities in India and the world. Sampling was conducted in different functional zones; namely, traffic intersections, industrial, and institutional areas, to estimate the concentration of different PM-bound heavy metals and VOCs in the ambient air using Inductively coupled plasma-optical emission spectrometry (ICP-OES) and gas chromatography (GC) respectively. Our results show that the concentration levels (of VOCs and PM) and health risks were maximum at the traffic intersection area, followed by the industrial and institutional areas. The major contribution to CR came from chloroform, naphthalene, and PM-bound chromium, while the contribution to NCR mainly came from naphthalene, trichloroethylene, xylenes, and PM-bound chromium, nickel, and cadmium. It was observed that CR and NCR from VOCs are quite comparable (average CRvoc 8.92E-05 and NCRvoc 6.82) to that from the PM-bound heavy metals (average CRPM 9.93E-05 and NCRPM 3.52). According to the sensitivity analysis performed using Monte-Carlo Simulation, it was also found that the output risk is most significantly influenced by the pollutant concentration followed by exposure duration and exposure time. The study reveals that Dhanbad city is not only a critically polluted area but also a highly hazardous and cancer-prone area due to the pollution arising from incessant coal mining activities and heavy vehicular movement. Given the paucity of data on exposure to VOCs in ambient air and their risk assessment pertaining to coal mining cities of India, our study provides useful information and insight for the regulatory and enforcing authorities to devise appropriate strategies for air pollution and health risk management in such cities.

Evaluation of the Impact of COVID-19 Restrictions on Air Pollution in Russia’s Largest Cities

Governments around the world took unprecedented measures, such as social distancing and the minimization of public/industrial activity, in response to the COVID-19 pandemic in 2020. This provided a unique chance to assess the relationships between key air pollutant emissions and track the reductions in these emissions in various countries during the lockdown. This study considers atmospheric air pollution in the 78 largest Russian cities (with populations over 250,000) in March–June of 2019–2021. This is the first such study for the largest cities in Russia. The initial data were the TROPOMI measurements (Sentinel-5P satellite) of such pollutants as carbon monoxide (CO), formaldehyde (HCHO), nitrogen dioxide (NO2), and sulfur dioxide (SO2), which are the main anthropogenic pollutants. The data were downloaded from the Google Earth Engine’s cloud-based geospatial data platform. This provided L3-level information for subsequent analysis. The TROPOMI data indicated a decrease in the atmospheric content of the air pollutants in the largest Russian cities during the lockdown compared to the pre-pandemic and post-pandemic periods. The reduced economic activity due to the COVID-19 pandemic had the greatest impact on NO2 concentrations. The average reduction was −30.7%, while the maximum reduction was found within Moscow city limits that existed before 01.07.2012 (−41% with respect to the 2019 level). For sulfur dioxide, the average decrease was only 7%, with a further drop in 2021 (almost 20% relative to 2019). For formaldehyde and carbon monoxide, there were no reductions during the 2020 lockdown period (99.4% and 100.9%, respectively, with respect to 2019). The identified impacts of the COVID-19 lockdown on NO2, SO2, HCHO, and CO NO2 concentrations in major Russian cities generally followed the patterns observed in other industrialized cities in China, India, Turkey, and European countries. The COVID-19 pandemic had a local impact on NO2 concentration reductions in major Russian cities. The differences leveled off over time, and the baseline pollution level for each pollutant was restored.

Study on the Temporal and Spatial Distribution of Air Pollutants in Typical Cities of China

The present study selects cities such as Zhengzhou, Kaifeng, Anyang, Hebi, Xinxiang, Jiaozuo, and Puyang along the Yellow River Basin in Henan Province. The data of six pollutants, such as PM2.5, PM10, SO2, CO, NO2, and O3, in various cities from 2019 to 2021, and the monthly primary pollutant data of seven cities in the past five years were collected through various channels. The air quality of the above seven cities was analyzed with the spatial-temporal distribution of pollutants as the research objective and geographic information system as the research tool. The results show that affected by the distribution of key pollution sources and meteorological conditions in the urban area, the PM2.5 concentration generally shows a zonal feature of decreasing from northwest to Southeast. The high-value area is located in the north and west of the integrated area of the seven cities, and the low-value area is located in the Southeast of the seven cities.