Winter Air Quality: Varanasi Leads In Cleaner Winter Air, Delhi Slips

BY A STAFF REPORTER: In a research conducted by Climate Trends on Winter Air Quality in major Indian Cities, Varanasi emerged as the only city among seven others to meet the national standards for PM2.5 during the winter of 2022-23 and 2023-24. 

The results are based on a research study conducted by Climate Trends which performed a comparative analysis of the PM2.5 levels during the winter season in major Indian cities. The PM2.5 (Particulate Matter) levels are a mixture of harmful substances in the air that can be harmful to the lungs when inhaled. 

Varanasi performed well despite coming under the highly polluted Indo-Gangetic Plain (IGP) Region. However, despite receiving focused attention, Delhi's PM2.5 levels were relatively higher (405.24) in the winter months of 2023-24. Delhi also emerged as the most polluted city followed by Patna and Chandigarh. Along with Varanasi, Mumbai also demonstrated lower pollution levels compared to the previous year's performance and met the national standards during the winter months of 2023-24. 

Moreover, Kolkata and Lucknow failed to meet the national standards during the winter months of both phases. However, both cities along with Patna saw enhanced pollution levels compared to the preceding year. Delhi and Chandigarh were the only cities that demonstrated an increase in pollution levels in winter months compared to the previous phase.

The PM2.5 concentration in Varanasi showcased significant fluctuations with values ranging from relatively low (5.62) to very high (121.61) levels. In Delhi, the PM2.5 levels ranged from relatively low (9.46) to very high (405.24). Chandigarh showcased PM2.5 levels ranging from relatively low (11.24) to very high (283.26) levels. While Kolkata's PM2.5 levels ranged from relatively low (7.53) to very high (151.08). Mumbai's PM2.5 levels ranged from relatively low (14.35) to very high (144.43). PM2.5 levels in Patna ranged from relatively low (16.89) to very high (293.68) levels. Lastly, Lucknow's PM2.5 levels ranged from relatively low (9.43) to very high (148.8) levels.

Furthermore, The study demonstrated winter pollution levels for the winter period beginning on October 1st to February 28th. It was observed that the winter pollution levels in the cities, except Chandigarh, were lower in January and February despite decreased temperatures. This might be due to a few meteorological factors including windspeeds and crop burning in several North Indian states.

Further, the research also advocated for a thorough analysis to understand the improved levels in some cities and implement effective measures in others.

As winter pollution is emerging as a major threat to the global environment and human health, Climate Trends conducted research to compare the PM2.5 levels during the winter season across major Indian cities namely Mumbai, Varanasi, Patna, Delhi, Chandigarh, Lucknow, and Kolkata, for the years 2022-2023 and 2023-2024.