Farm fires top pollutant list

Despite fewer farm fires in Punjab and Haryana so far this year compared to 2023, they still accounted for over 20% of Delhi's total PM 2.5 (particulate matter with a diameter of less than 2.5 microns) in Delhi over the past three days, according to the Centre's Decision Support System (DSS).

- Jasjeev Gandhiok

It estimated the transport sector as the next biggest contributor at over 11% over the past two days.

Calculating the actual contribution of stubble smoke by factoring in the fire count recorded a day earlier, DSS said it accounted for 22.77% of Delhi's PM 2.5 on Wednesday, 20.38% on Tuesday and 23.3% on Monday a key factor that has kept Delhi's air quality index reading above 350 ("very poor") during this period.

At the same time, though transport-level winds, which blow at a height of over lkm are northwesterly and strong, surface-level winds in Delhi, which blow below 100 metres in height, have largely remained calm.