NEW DELHI: Delhi's air quality deteriorated further on Friday, with the overall Air Quality Index (AQI) reaching 391 at 9 am, placing it close to the 'severe' category, two days ahead of Diwali.
Of the 59 air quality monitoring stations across the national capital, 30 recorded readings in the severe category, while the remaining stations reported very poor air quality, according to data cited by the Central Pollution Control Board (CPCB).
Rohini was the worst-affected area, recording an AQI of 475, followed by IIT Delhi at 472. The readings reflect a worsening pollution situation as a thick layer of smog continued to cover parts of the city.
Delhi's air quality has remained in the very poor category for five consecutive days. The city's average AQI was 324 on Monday, 350 on Tuesday and 377 on Wednesday. It stood at 369 at 4 pm on Thursday before rising further on Friday morning.
Under CPCB's classification, an AQI between 301 and 400 is considered very poor, while readings above 400 fall in the severe category. Prolonged exposure to very poor air can cause respiratory illness, while severe air quality poses health risks even to otherwise healthy people.
The Air Quality Early Warning System has forecast that Delhi could record its first severe air quality day of the season on Friday, with pollution levels likely to remain in the severe category until November 8, the day of Diwali.
The worsening conditions come during the peak stubble-burning period in northern India. Firecracker emissions during Diwali could add to the pollution load. Unfavourable weather conditions, including low wind speeds, are also limiting the dispersal of pollutants.
The Decision Support System for Air Quality Management estimated that stubble burning contributed around 15.6 per cent of Delhi's PM2.5 pollution on Thursday. Its contribution was projected to rise to 19.2 per cent on Friday before falling sharply over the weekend. Transport emissions are expected to account for a larger share.
The forecast indicates that pollution could remain a concern even after the festival, with changing wind patterns likely to influence air quality in the following days.
With inputs from media reports