Firecrackers caused 71 per cent of Delhi PM2.5 pollution on Diwali night
An assessment by the Indian Institute of Tropical Meteorology shows fireworks were the primary contributor to the post-festival pollution spike.
Firecrackers contributed 71.1 per cent of PM2.5 pollution in Delhi between 1 am and 9 am on November 9, according to an assessment by the Indian Institute of Tropical Meteorology (IITM), Pune, as reported by Hindustan Times.
The IITM study, which operates the Air Quality Warning and Integrated Decision Support System for Emissions (AIRWISE) for Delhi, found that firecracker emissions significantly outpaced other sources during the early hours after Diwali celebrations.
On November 9, vehicle emissions contributed 6.9 per cent to PM2.5 levels, while secondary inorganic aerosols accounted for 5 per cent and secondary organic aerosols for 4.5 per cent, according to Business Standard.
The impact of the fireworks continued into the following day, with firecrackers accounting for 29.8 per cent of PM2.5 between 1 am and 9 am on November 10.
The pollution spike coincided with high PM2.5 readings at several stations, including 4,985 micrograms per cubic metre in Jahangirpuri and 2,808 micrograms per cubic metre in Nehru Nagar at 3 am on November 9.
The Central Pollution Control Board (CPCB) clarified that its monitoring instruments are calibrated up to 1,000 micrograms per cubic metre, and hourly readings exceeding this limit are excluded from Air Quality Index (AQI) calculations.