Authorities have in recent weeks implemented restrictions on traffic and construction as they seek to curb smog in New Delhi, home to more than 30 million people.
Vehicles account for 23 per cent of Delhi’s winter pollution, while biomass burning, including farm stubble fires, contributes 20 per cent, according to India’s environment ministry.
Industry, including coal-fired power plants, contributes about 9 per cent.
The largest share, 27 per cent, comes from secondary particles, formed when gases released by vehicles, industry, power plants and biomass burning react in the atmosphere.
A 2024 study published in The Lancet Planetary Health, a peer-reviewed research journal, estimated that 3.8 million deaths in India between 2009 and 2019 were linked to air pollution.
