A new 25-year satellite study has revealed that pollution levels in North-East India have increased sharply over the past two decades, pushing most parts of the region from “polluted” to “highly polluted” categories due to rising carbonaceous aerosols linked to biomass burning and slash-and-burn farming practices. The research, published in the journal Atmospheric Environment, was led by Prof Abhijit Chatterjee and research fellow Soumen Raul of Bose Institute. The study analysed particulate matter pollution trends across the Indo-Gangetic Plain, North-East India and the Himalayas between 2000 and 2024.
According to the findings, organic carbon and sulphate components of particulate matter rose nearly 50 per cent in North-East India during 2010-2019 compared to the previous decade. Pollution hotspots earlier limited to Assam, Meghalaya and Tripura have now expanded further across the region and into Bangladesh. The study blamed intensified slash-and-burn agriculture and extensive use of biomass such as firewood, crop residue and cow dung for cooking and heating in rural households as the major drivers of pollution. Researchers said India’s National Clean Air Programme (NCAP), currently focused mainly on cities, has failed to address the growing rural pollution crisis.
The report also highlighted worsening industrial pollution in Assam, especially around Bongaigaon, Guwahati, Dibrugarh, Digboi, Numaligarh and Bokajan, where sulphate emissions from thermal power plants, oil refineries and cement industries increased by over 30 per cent after NCAP implementation. In Guwahati, environmental experts and traders expressed concern over the findings, saying rising pollution could impact public health, tourism and long-term economic activities in the city if stronger mitigation measures are not introduced. Researchers have urged the government to expand NCAP 2.0 to include rural and ecologically sensitive regions of North-East India.