Air pollution across the Indo-Gangetic Plain and eastern India has worsened sharply over the last two decades, with Bihar and West Bengal emerging among the country’s most polluted regions, according to a new study by Bose Institute.

Published in the journal Atmospheric Environment, the satellite-based research analysed pollution patterns between 2000 and 2024 across the Indo-Gangetic Plain, the Himalayas and north-eastern India.

Pollution now reaching Himalayan regions

Researchers found that pollution generated in the plains is no longer remaining confined to urban and industrial zones. Instead, emissions are increasingly travelling into ecologically sensitive Himalayan regions.

The study revealed that pollution from Punjab, Haryana and Delhi is affecting western and central Himalayan areas, while emissions from Bihar and West Bengal are impacting the eastern Himalayas.

Scientists warned that aerosols such as soot, dust and chemical particles can travel long distances and worsen both climate conditions and public health.

Bihar and Bengal emerge as major hotspots

The analysis found that pollution levels during 2010-2019 rose by more than 20 per cent compared to the previous decade.

Initially concentrated in parts of Bihar, Uttar Pradesh and northern West Bengal, high-pollution zones have now expanded across almost the entire regions of Bihar and West Bengal, along with parts of Assam, Meghalaya and Tripura.

Researchers linked much of this increase to rural biomass burning, including agricultural waste burning, household fuel use and urban waste disposal.

Rural pollution challenge remains ignored

The study also evaluated the impact of India’s National Clean Air Programme and found that while some urban centres showed improvements, rural pollution remains largely unaddressed.

Researchers said the programme continues to focus mainly on cities, while pollution caused by biomass burning in rural regions is growing rapidly.

The report further warned that pollution is no longer only an urban issue but a wider regional crisis affecting plains, villages and mountain ecosystems alike