Kolkata tops list of cleanest air among Indian metros
What's the story
Kolkata has been named the Indian metro with the cleanest air quality, according to a new study by the Centre for Science and Environment (CSE). The research, published in its annual report "State of India's Environment in Figures 2025," tracked air quality over 1,550 days from January 2021 to October 2023. Kolkata recorded 791 days of "very good" or "satisfactory" air quality during this period.
Pollution control
Role of WBPCB in improving air quality
Kolkata had 368 days of "very good" and 423 days of "satisfactory" air quality. The city had no days with "severe" pollution or hazardous exposure, a stark contrast to Delhi, which recorded 284 such days. The West Bengal Pollution Control Board (PCB) played a key role in this improvement through strategic actions like dust control measures, clean fuel initiatives, and promoting smokeless stoves.
Pollution management
National Clean Air Programme's impact on cities
The National Clean Air Programme (NCAP) has been instrumental in monitoring pollution and enforcing remedial action across cities. Under NCAP, cities update the Central Pollution Control Board's PRANA portal quarterly, setting targets and outlining funding needs. CSE air quality expert Anumita Roychowdhury emphasized the importance of this framework in laying the foundations for national air quality management in non-attainment cities like Kolkata.
Regional comparison
Performance of other southern and western cities
Southern metros such as Bengaluru, Hyderabad, and Chennai mostly recorded "poor" air quality days but did not witness severe pollution spikes. Mumbai had a mixed pattern with 145 "very good," 637 "satisfactory," and 649 "poor" AQI days. The city avoided the worst levels of pollution with only one "very poor" day recorded during this period.