Delhi ranked as the most polluted among 33 states and Union territories with an annual mean PM2.5 concentration of 101 micrograms per cubic metre, 2.5 times the Indian standard and 20 times the WHO guideline, according to a new satellite-based analysis.

The report by the independent research organisation Centre for Research on Energy and Clean Air said Chandigarh recorded the second-highest annual average PM2.5 level at 70 micrograms per cubic metre during the study period from March 2024 to February 2025, followed by Haryana at 63 and Tripura at 62.