NEW DELHI: Exposure to air pollutant PM 2.5 from the burning of domestic biomass (chulha) is the deadliest source of air pollution in India, responsible for around 25% of all pollution-linked deaths in the country, according to a study.

The study, ‘Burden of Disease Attributable to Major Air Pollution Sources in India’, found that the burning of biomass or solid fuel was the biggest source of PM 2.5 in both cities and villages. The situation could be worse as the study did not measure its indoor impact.

“Residential biomass burning also impacts outdoor air quality, so the emissions exit the kitchen area and cause high exposure outside,” said Chandra Venkataraman , a scientist at IIT-Bombay who led a part of the study.

The research was conducted by IIT-Bombay and the US-based Health Effects Institute and Institute for Health Metrics and Evaluation (IHME).

The study attributed nearly 26.7 lakh deaths in India to the burning of biomass at home in 2015. Coal combustion was the second biggest source, causing 15.5% of all, or 16.6 lakh deaths. Agricultural burning — though the practice is limited to some northern and central states — caused 66,000 deaths.

Even in Delhi, the largest source of PM 2.5 exposure is residential biomass burning, followed by open burning of trash, according to the study. This may be due to the use of ‘ chulhas ’ and solid fuels in the rural areas surrounding Delhi.

In fact, PM 2.5 pollution from the entire Indo-Gangetic plains area can travel to Delhi, scientists said. Venkataraman warned that this could be the tip of the iceberg, and said the deaths linked to PM 2.5 could increase substantially if proper action was not taken.

