Delhi air pollution exceeds WHO limit by 30 times ahead of Diwali

Delhi air pollution exceeds WHO limit by 30 times ahead of Diwali

Air pollution in India’s capital, New Delhi, worsened sharply on Wednesday, with toxic fine particulate matter (PM2.5) concentrations exceeding the World Health Organisation’s recommended daily limit by more than 30 times, according to air quality monitoring data.

The deterioration came just three days after authorities introduced stricter measures to tackle the city’s worsening smog, including restrictions on vehicle movement and construction activities. The wider Delhi metropolitan area is home to more than 30 million people and remains among the world’s most polluted urban centres.

Pollution levels are expected to rise further ahead of Diwali, the Hindu festival of lights, which falls on Sunday. Fireworks traditionally used during the celebrations add to the city’s already hazardous air quality.

Earlier this month, India’s Supreme Court permitted the limited use of so-called green firecrackers, which produce fewer emissions than conventional fireworks. However, authorities frequently struggle to enforce restrictions, and firecracker explosions continue to contribute to pollution during the festival.

According to air monitoring company IQAir, PM2.5 concentrations reached more than 461 micrograms per cubic metre in some parts of New Delhi on Wednesday. These microscopic particles can penetrate deep into the lungs and enter the bloodstream, increasing the risk of serious health problems, including cancer.

India’s environment ministry estimates that vehicles contribute 23 per cent of Delhi’s winter air pollution, while biomass burning, including agricultural stubble fires, accounts for another 20 per cent. Industrial activities, including coal-fired power generation, contribute approximately nine per cent.

However, secondary particles represent the largest share, accounting for 27 per cent of pollution. These particles form when gases released by vehicles, factories, power plants and biomass burning react in the atmosphere.

Jacob Koshy, author of a recently published book on pollution, also points to the extensive use of fertilisers on agricultural land surrounding the capital as a factor contributing to the formation of these harmful particles.