According to a recent satellite based survey, Delhi was the most polluted of 33 states and Union territories, with an annual mean PM2.5 concentration of 101 micrograms per cubic meter 2.5 times the Indian standard and 20 times the WHO guideline.
During the study period from March 2024 to February 2025, Chandigarh recorded the second highest annual average PM2.5 level at 70 micrograms per cubic meter, followed by Haryana at 63 and Tripura at 62, according to a report by the independent research organization Centre for Research on Energy and Clean Air.
Additionally, Assam (60), Bihar (59), West Bengal (57), Punjab (56), Meghalaya (53), and Nagaland (52) surpassed the national average.
The National Ambient Air Quality Standard (NAAQS) for yearly PM2.5 of 40 micrograms per cubic meter was exceeded by 447 of the 749 districts (60%) examined.
The investigation revealed that the most contaminated regions are concentrated in a small number of states.
Nearly half of the top 50 was made up of Delhi (11 districts) and Assam (11 districts), followed by Bihar (7) and Haryana (7).
West Bengal (2), Rajasthan (2), Tripura (3), and Uttar Pradesh (4) are additional contributors. Every monitored district exceeded the NAAQS in a number of states. Delhi, Assam, Punjab, Haryana, Chandigarh, Himachal Pradesh, Meghalaya, Tripura, and Jammu and Kashmir are among them.
In a number of other districts, including Bihar (37 of 38), West Bengal (22 of 23), Gujarat (32 of 33), Nagaland (11 of 12), Rajasthan (30 of 33), and Jharkhand (21 of 24), the vast majority of districts violated the criteria.
Due to a lack of ground monitoring data during the study period, Ladakh, the Andaman and Nicobar Islands, and Lakshadweep were not included in the analysis.
