11 Assam districts among India's top 50 most polluted: CREA report

Guwahati: Assam is rapidly emerging as one of India’s most polluted states, with eleven of its districts among the top 50 most polluted in the country, according to a satellite-based PM2.5 assessment conducted across India’s airsheds, states, and districts.

The study by the Centre for Research on Energy and Clean Air (CREA), an independent research organisation, found that Delhi and Assam together account for nearly half of the top 50 most polluted districts, followed by Bihar and Haryana with seven districts each.

Other states with districts in the top 50 include Uttar Pradesh (4), Tripura (3), Rajasthan (2), West Bengal (2), and single districts from Chandigarh, Meghalaya, and Nagaland.

Several states are in full non-compliance with the National Ambient Air Quality Standards (NAAQS), where all monitored districts exceed permissible PM2.5 levels.

These include Delhi, Assam, Punjab, Haryana, Chandigarh, Himachal Pradesh, Meghalaya, Tripura, and Jammu and Kashmir.

In Assam, all 34 monitored districts exceeded NAAQS limits in 2024.

The report noted that Assam, Delhi, Punjab, and Tripura consistently exceed PM2.5 standards throughout the year, including during the monsoon season, when air quality generally improves in other parts of India.

During the monsoon, 21 districts in Assam, nine in Delhi, 15 in Punjab, and six in Tripura exceeded the prescribed limits.

The study highlighted the Northeastern states, particularly Assam and Tripura, as unexpected pollution hotspots, appearing in the top five districts for pollution across winter, summer, and monsoon seasons.

CREA recommended that states develop district-level air quality action plans using satellite data to identify high-exposure areas, prioritise vulnerable populations, and allocate mitigation resources efficiently.

The report emphasized addressing major regional sources, including power generation, industrial activity, biomass burning, and transport, to reduce persistent PM2.5 pollution in Assam and across the Indo-Gangetic Plain.