Urban Air Pollution in Five Major Cities of Rajasthan, India: Spatiotemporal Assessment Using Multi‐Pollutant Indices

A COMPARATIVE STUDY OF AIR QUALITY INDEX (AQI) IN SELECTED CITIES OF MAHARASHTRA

Air pollution is a major environmental and public health concern in India, driven by rapid urbanization, industrialization, vehicular emissions, and construction activities. This study presents a comparative analysis of the Air Quality Index (AQI) of five major cities in Maharashtra—Mumbai, Pune, Nagpur, Nashik, and Chhatrapati Sambhajinagar (Aurangabad)—using secondary data from the Central Pollution Control Board (CPCB) and Maharashtra Pollution Control Board (MPCB). The analysis shows that Mumbai and Pune generally record higher AQI levels due to heavy traffic and industrial activities, while Nashik experiences relatively better air quality. AQI tends to worsen during winter and improve during the monsoon because of seasonal meteorological conditions. The study highlights the need for effective pollution control measures, sustainable urban planning, improved public transport, and continuous air quality monitoring to safeguard environmental quality and public health.

Integrated weighted geospatial analysis and spatiotemporal assessment of key criteria air pollutants for hotspot identification and air quality risk assessment.

Air pollution remains a pressing concern in urban India, affecting human wellbeing and ecosystem sustainability. This investigation explores the spatial and temporal variations in 10 μm particulate matter (PM10), nitric oxides (NOX), and sulfur dioxide (SO2) air pollution in Navi Mumbai, India, from 2014-2023. Data from 23 monitoring points were analyzed using geographic information systems-based methods, including inverse distance weighting and weighted overlay analysis, to generate a comprehensive pollution index. Findings indicate high seasonal variation, with elevated PM10 and NOX levels during premonsoon and winter due to traffic, industrial activity, and unfavorable meteorological conditions. Monsoon rains significantly reduced pollutant levels. Industrial hotspots, particularly in Taloja and Kalamboli, and traffic-heavy corridors, such as Vashi and Nerul, remained persistent pollution sources. A noticeable drop in pollutant concentrations in 2020 coincided with the COVID-19 lockdown, although levels surged in subsequent years. The weighted overlay analysis proved effective in identifying pollution hotspots and offering a comprehensive understanding of air quality risks. Global comparisons highlight the specific challenges of coastal satellite cities, where industrial and harbor emissions contribute to seasonal smog. This study emphasizes the need for targeted emission controls and urban planning interventions to improve air quality and sustainability in rapidly growing regions.

Assessing the spatiotemporal characteristics of urban air pollution in Ado-Ekiti and its environs, southwest Nigeria

Air pollution poses significant environmental and public health challenges in rapidly urbanising regions of sub-Saharan Africa, where ground-based monitoring infrastructure remains limited. This study examined the spatiotemporal distribution of key air pollutants in Ado-Ekiti and its environs, Nigeria, from 2019 to 2024. Columnar concentrations of carbon monoxide (CO) and formaldehyde (HCHO) were retrieved from Sentinel-5P, while MODIS aerosol optical depth data was used to estimate particulate matter (PM2.5 and PM10). Meteorological variables (rainfall, wind speed, and wind direction components u and v) were derived from the Weather Research and Forecasting model, and one week of ground-based measurements of pollutants were collected to enable correlation analysis with satellite-derived estimates. All datasets were aggregated to monthly and annual timescales, resampled to a 1 km spatial resolution and re-projected to UTM Zone 31 N. Results indicated that particulate matter dominated the pollutant profile, with annual mean concentrations of 59.37–65.29 µg/m³ for PM2.5 and 89.35–99.51 µg/m³ for PM10, exceeding WHO guideline limits. Peak concentrations occurred during the Harmattan season, with PM₂.₅ > 100 µg/m³ and PM₁₀ > 200 µg/m³, driven primarily by Saharan dust transport and local activities. Mann-Kendall trend analysis revealed significant increasing trends in HCHO, PM2.5, and PM10, whereas CO showed no significant trend. Satellite-derived particulate estimates showed positive but weak correlations with ground-based particulate concentrations (r < 0.20), whereas rainfall significantly reduced particulate levels, and meridional winds (v) facilitated long-range PM₁₀ transport. This study provides a significant integrated satellite model for air quality assessment in data-scarce urban environments while providing evidence to support targeted emission control strategies.

Geospatial Assessment of Urban Air Pollution Using Multi-Source Remote Sensing and GIS: A Case Study of Nashik City, India

Abstract. Rapid industrialization and unplanned urbanization have increased air pollution levels across Indian cities, posing serious environmental and health challenges. This research presents a geospatial assessment of air pollutant behaviour across Nashik city by integrating multi-source remote sensing datasets and real observation datasets from Sentinel-5P, NASA POWER, and CPCB ground observations within a GIS-based analytical framework. Using ward-level mapping and spatial overlays, the study examines the distribution of key pollutants - PM2.5, PM10, NO2, SO2, and CO - and their relationship with environmental and anthropogenic parameters, including land use, road networks, wind direction, temperature, and vegetation density. The results consistently reveal high concentrations of PM2.5, ranging from a minimum of 52.4 μg/m³ to a maximum of 73 μg/m³, and PM10, a minimum of 87.3 μg/m³ and a maximum of 121.5 μg/m³, particularly along high-traffic corridors and industrial zones, which exceed the WHO standards. Correlations with meteorological and vegetative factors further highlight the influence of urban form and climatic conditions on pollutant dispersion. This integrated approach demonstrates how multi-source remote sensing and GIS tools can be effectively employed to identify emission hotspots, support evidence-based policy formulation, and strengthen urban environmental management strategies for sustainable development.

Socioeconomic impacts and spatiotemporal assessment of environmental pollution in Mekelle City, Northern Ethiopia

Investigating the pollution and air quality situation in Kabul city: Focusing on the concentration of major pollutants and the air quality index

Concentration of different pollutants such as O₃ , NO₂ , SO₂ , CO, PM₁₀ , and PM2.5 in the atmosphere is called air pollution, which created several challenges in the environment and is considered one of the dangerous phenomenal in the current world, in Afghanistan urbanization in last two decades had significant impact on air quality. There is different source of air pollution in urban areas such as industries, more population, transportation system, less vegetation covers and etc. The main goal of this of this research is to analyze the pollutant levels from 2021 to 2024 in Kabul city by analyzing of six major pollutants including O₃ , NO₂ , SO₂ , CO, PM₁₀ , and PM2.5 and comparing them with national standard and by using the AQI to analyses the air quality. This is a quantitative research; data has been collected from National Environmental protection Agency air quality station based in Darulaman area of Kabul city. Significant annual and seasonal variations in pollutant concentrations were found by the results. O₃ concentrations exceeded the national norm during the winter months, ranging from 14 µg/m³ (June 2023) to 181 µg/m³ (December 2022). Particularly in late 2024, NO₂ and SO₂ exhibited significant peaks, with NO₂ reaching 258 µg/m³ and SO₂ reaching 150 µg/m³, both of which exceeded allowable limits. With maximum readings of 221 µg/m³ and 157 µg/m³, respectively, PM₁ 0 and PM₂ .5 were continuously over national norms for a number of months. According to the analysis of the Air Quality Index (AQI), PM₂ . ₅ was the main pollutant affecting the general quality of the air. The AQI rating was at its lowest (79) in September 2022 (Moderate) and at its worst (207) in January 2021 (Very Unhealthy). Seasonal trends revealed that while air quality improved somewhat during some summer months, especially in 2022, it deteriorated during the winter months of November through January. Overall, the results show a trend toward worsening air quality in 2023 and 2024, particularly as a result of particle matter pollution.