The national capital recorded its worst air quality in 287 days, with the Air Quality Index (AQI) settling at 348 and 10 monitoring stations reporting severe pollution levels on Tuesday. Delhi last recorded a higher AQI on January 20 this year, when the index stood at 378.
Of the 57 air quality monitoring stations in the city, 10 recorded severe air quality, 35 were in the very poor category, and 12 reported poor air quality. Jahangirpuri recorded the worst air quality, with an AQI of 462, falling in the severe category.
According to the Central Pollution Control Board (CPCB), an AQI between zero and 50 is classified as good, 51 and 100 as satisfactory, 101 and 200 as moderate, 201 and 300 as poor, 301 and 400 as very poor, and 401 and 500 as severe.
PM2.5 was the most dominant pollutant in Delhi. These fine particulate matter particles, measuring 2.5 micrometres or less in diameter, can penetrate deep into the lungs and even enter the bloodstream, posing significant health risks.
The Air Quality Early Warning System for Delhi forecasts that the city’s air quality is likely to remain in the very poor category from November 4 to 6. The outlook for the next six days suggests air quality will likely remain in the very poor to severe category.
Delhi was brought under Stage II of the Graded Response Action Plan (GRAP) on Monday after the AQI deteriorated to the very poor category, settling at 324 and marking the first such day of the season.
The Decision Support System (DSS) said stubble burning accounted for 15.3 per cent of Delhi’s pollution, while transport emissions contributed 15.8 per cent. Other local sources included energy production (1.2 per cent), industries in Delhi and the periphery (3 per cent), waste burning (1.4 per cent), construction activities (2.2 per cent), road dust (1.2 per cent), residential sources (3.9 per cent) and other sectors (1 per cent).
Among the neighbouring NCR districts, Jhajjar contributed 8.8 per cent, Gurugram 4.1 per cent, Sonipat 2.6 per cent, Rohtak 2.5 per cent and Mewat 2 per cent.