NEW DELHI: Delhi remained India's most polluted megacity by a wide margin during the 2024-25 winter, with an average PM2.5 concentration of 175 micrograms per cubic metre, according to an analysis released on Tuesday.
However, the Centre for Science and Environment analysis found that PM2.5 pollution in the national capital declined in the 2024-25 winter (October 1 to January 31) compared to the 2023-24 winter (189 micrograms per cubic metre).
Kolkata was the second-most polluted megacity during the 2024-25 winter, with an average PM2.5 concentration of 65 micrograms per cubic metre.
The analysis showed that PM2.5 levels declined in Bengaluru, Mumbai and Kolkata compared to the previous winter but remained the same in Chennai and Hyderabad.
The average PM2.5 levels during the 2024-25 winter were 52 micrograms per cubic metre in Hyderabad, 50 in Mumbai, 37 in Bengaluru and 36 in Chennai.