Firecrackers caused 71 per cent of Delhi PM2.5 pollution on Diwali night
Data from the Indian Institute of Tropical Meteorology shows firecracker emissions were the primary contributor to fine particulate matter after celebrations.
Firecrackers accounted for 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, reported by The Indian Express.
The study, based on the Ministry of Earth Sciences' Real-Time Source Apportionment system, found that firecrackers were the leading source of pollution for three consecutive days. Their contribution was 43.4 per cent on November 8 and 29.8 per cent on November 10.
Air quality monitoring stations recorded extreme spikes during this period. PM2.5 levels reached 4,985 micrograms per cubic metre in Jahangirpuri and 2,808 micrograms per cubic metre in Nehru Nagar at 3 am on November 9.
Urban Acres reported that data gaps in Delhi Pollution Control Committee (DPCC) and Central Pollution Control Board (CPCB) records raised questions about the completeness of air-quality data. At RK Puram, PM2.5 reached 2,389 micrograms per cubic metre at midnight, far exceeding the 60 micrograms per cubic metre limit.
Manoj Kumar, an analyst at the Centre for Research on Energy and Clean Air, noted that CPCB data for the night remained unavailable. Sunil Dhaiya, founder and lead analyst at Envirocatalysts, stated that incomplete records could make it difficult to assess health risks or evaluate pollution-control measures.
The CPCB clarified that any pollution readings exceeding 1,000 are not included in the 24-hour Average Air Quality Index (AQI) calculation. The watchdog explained that the AQI is capped at 500 because any value above that threshold remains in the 'Severe' category.