Delhi’s air quality deteriorated once again to hit the ‘severe’ category Thursday morning with a 24-hour average AQI of 426 at 9 am. The worst air quality in the city was at Jahangirpuri and Anand Vihar where the monitoring stations recorded a 24-hour average AQI of 460, according to data from the Central Pollution Control Board (CPCB).

The prominent pollutant at Jahangirpuri was PM2.5, while PM10 was found to be the most prominent pollutant at Anand Vihar.

Air Quality Index between 401 and 500 is considered to be ‘severe’. According to the CPCB, AQI in the ‘severe’ category “affects healthy people and seriously impacts those with existing diseases”.

Most other parts of the National Capital Region (NCR) recorded 24-hour average AQI in the ‘very poor’ category at 9 am on Thursday. Noida recorded an AQI of 388 and Gurgaon 391. Delhi’s air quality remained the worst among the parts of the NCR that are being monitored by the CPCB.

Data from the India Meteorological Department (IMD) shows that calm conditions with a wind speed of 0 kmph prevailed at 8.30 am Thursday. Calm conditions prevent the dispersion of pollutants that then accumulate in the air.