An Evaluation of Air Quality in Major Urban Areas of India

Journal Article · Thu Apr 09 00:00:00 EDT 2026 · Environmental Research Communications

DOI:https://doi.org/10.1088/2515-7620/ae5926· OSTI ID:3029713

Ghosh, Saikat; Farooqui, Z.; Saha, Jayita; Biswas, Jhumoor

Rapid economic growth and burgeoning population have contributed to enhanced levels of PM2.5 concentrations in urban regions of India. Evaluation of ambient air quality facilitates the assessment of effectiveness of emission control measures and early identification of new sources. This study provides a comprehensive statistical analysis of PM2.5 concentrations in key urban areas across India, including Delhi, Kolkata, Mumbai, Chennai, Hyderabad, and several regional centers. Data from 2017 to 2023 was analyzed using trend analysis, cluster analysis, principal component analysis, and geostatistical interpolation to understand spatiotemporal variations and sources. The analysis reveals significant differences in spatial distribution of PM2.5 concentrations with high annual averages in urban regions in Indo-Gangetic plain (82–123 µg m-3) and relatively lower concentrations (29–46 µg m-3) in southern urban areas of Kerala, Tamil Nadu and Andhra Pradesh. Delhi state had the highest 24-averaged PM2.5 concentrations (112 µg m-3) followed by urban regions in Uttar Pradesh, Bihar and West Bengal (94 µg m-3). Trend analysis from 2017 to 2023 revealed an overall 2.5% decline in site-wide PM2.5 concentrations, with the exception of Ludhiana, which exhibited a consistent annual increase of 10%. Principal component analysis (PCA) attributes 30% of the variance to wintertime emissions, 13% to biomass burning, and 18% to the regional haze in the northern Indo-Gangetic Plain. Different analyses clearly demonstrates the contribution of biomass burning to pollution in Delhi and surrounding cities. Transboundary pollution to Kolkata is likely from the highly polluted region in Indo-Gangetic Plain. Coastal cities of Mumbai and Chennai has relatively lower pollution attributed to the influence of sea breeze dilution, with mostly local contribution and some potential transport from upwind industry clusters. Hyderabad also has local contribution due to high density of vehicular traffic and local small industries. This study shows that mitigation efforts targeting clusters of regions should be undertaken to curb the high PM2.5 pollution. Policy measures should be implemented both at local and the intra-state level to address shared sources and transport of pollution.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
• Sponsoring Organization: USDOE
• Grant/Contract Number: AC05-76RL01830
• OSTI ID: 3029713
• Report Number(s): PNNL-SA-207301
• Journal Information: Environmental Research Communications, Journal Name: Environmental Research Communications Vol. 8
• Country of Publication: United States
• Language: English