NEW DELHI: Delhi has ranked as the most polluted among 33 states and Union Territories, recording an annual mean PM2.5 concentration of 101 micrograms per cubic metre (\mu g/m^3)—a level 2.5 times higher than the Indian standard and a staggering 20 times the World Health Organization (WHO) guideline.
The grim figures come from a new satellite-based analysis conducted by the independent research organisation, the Centre for Research on Energy and Clean Air (CREA), covering the period from March 2024 to February 2025.
Widespread Pollution Across India
- The CREA report highlighted the severe and widespread nature of the pollution crisis across India:
- Top Ranks: Following Delhi, Chandigarh recorded the second-highest annual average PM2.5 level at 70 \mu g/m^3, followed by Haryana at 63 \mu g/m^3 and Tripura at 62 \mu g/m^3.
- National Standard Breached: Overall, 447 of the 749 districts (60 per cent) analyzed breached the National Ambient Air Quality Standard (NAAQS) for annual PM2.5 of 40 \mu g/m^3. States including Assam (60 \mu g/m^3), Bihar (59 \mu g/m^3), West Bengal (57 \mu g/m^3), Punjab (56 \mu g/m^3), Meghalaya (53 \mu g/m^3), and Nagaland (52 \mu g/m^3) all exceeded the national standard.
- Hotspots: The analysis found that the most polluted districts are heavily concentrated, with Delhi (11 districts) and Assam (11 districts) together accounting for nearly half of the top 50 list. Bihar (7) and Haryana (7) were also major contributors.
- Universal Failure: In several states and Union Territories, every monitored district exceeded the NAAQS, including Delhi, Assam, Punjab, Haryana, Chandigarh, Himachal Pradesh, Meghalaya, Tripura, and Jammu and Kashmir.
The report also noted that large majorities of districts in other states failed to meet the standard, such as Bihar (37 of 38) and West Bengal (22 of 23). Ladakh, Andaman and Nicobar Islands, and Lakshadweep were excluded from the analysis due to insufficient ground monitoring data.
