Air quality in Delhi set to turn ‘severe’, say experts

In Delhi, the air quality index deteriorated further and moved from the ‘very poor’ category to the ‘severe category’ in some areas on Sunday. The average settled at an average of 397.

On Sunday, Delhi's overall air quality index (AQI) stood at 367 at 9 am and improved to 352 at 4 pm. The 24-hour average AQI on Saturday was 397, the worst since January. It was 354 on Thursday, 271 on Wednesday, 302 on Tuesday, and 312 on Monday (Diwali).

“This is expected to remain similar or rise further in the next two days, as strong transport-level winds are bringing these pollutants to Delhi from the north-west direction. The contribution will only dip on November 2, as wind direction changes slightly,” Gufran Beig, founder project director, Safar told Hindustan Times.

“After Diwali, the AQI improved to the ‘poor’ category but then it again went back into the ‘very poor’ category and now we’re expecting that the situation will be like that till tomorrow. But there will be an improvement from November 2,” VK Soni, a scientist at India Meteorological Department (IMD) and part of the Commission for Air Quality Management (CAQM) sub-committee on Graded Response Action Plan (GRAP), told the National Herald.

Experts suggest that stubble burning in Punjab makes the situation worse.

Delhi’s AQI is expected to hover between ‘very poor’ and ‘severe’ till November 1. “Stubble burning happens every year and it affects the air quality of not only Delhi but the entire Indo-Gangetic Plain. But sometimes when the meteorological conditions are not favorable which is why we are experiencing poor air quality,” Soni said.

During this season, Soni said, the winds are from north-west coming from Punjab, and Haryana. With the onset of winter, the temperature will go down gradually, and the height at which pollutants can mix up in the air will also come down.

“As a result, the pollutants get accumulated near the surface. The wind is already very slow because of which the dispersion of pollutants is not there. We will hope that some kind of rain is there to settle down these pollutants,” he said.

CAQM introduced Stage-III of GRAP on Saturday evening with immediate effect, owing to forecasts which showed severe air in the coming days. The measures include a ban on construction and demolition (C&D) activities across NCR, shutting down brick kilns and hot mix plants not operating on clean fuels, and shutting down all stone crushers across NCR. It also includes a ban on mining across NCR.

Soni said that policies have been put into place to reduce the level of pollution in Delhi including the temporary shutting down of construction sites and a ban on demolition activities.

"In Delhi, the major source of pollution is transportation. That is the area in which people can contribute by avoiding personal transport and opting for public transport,” he said.