Sole hope: Smog will be gone with the wind

NEW DELHI: The

capital

experienced its most polluted day of the season on Sunday with the air quality index at a shocking 497. This was significantly worse than post-Diwali’s AQI of 445.

As thick layers of smog enveloped the city for a third consecutive day, PM2.5 and PM10 levels shot up. At several locations, they were 10 times higher than the permissible limit, through the day. The only bright spot in an otherwise dull day was the hope that things could improve, albeit marginally, on Monday and gradually since.

At

Anand Vihar

, the AQI touched a high of 500. PM10 levels were recorded between 1,640 and 1,690 micrograms per cubic metre (µg/m3) against a permissible level of 100µg/m3. At

RK Puram

and Punjabi Bagh, too, the AQI touched highs of 500, much as they did in

NSIT

Dwarka and IBHAS.

A Central Pollution Control Board statement stated: “Delhi has recorded the highest concentration of dust in the last 24 hours, probably due to variable wind pattern around the city.”

The dense presence of pollutants, including dust and smoke, in the atmosphere led to low visibility through the day. At Safdarjung, visibility was down to 200m in the morning. It improved slightly to 500m during the day. At IGI Airport, visibility was as low as 100m in the morning, improving to 700m during the day when the sun emerged briefly from the haze.

Officials said visibility remained below 500m for 21 hours at the IGI Airport between 5.30pm on Saturday and 5.30pm on Sunday.

While winter pollution is not a novelty for Delhi, the changing weather has had a huge role to play in the formation of the current smoggy conditions. Officials said the usual northwesterly winds over the plains helped disperse pollutants, but around October 28, just before Diwali, the wind shifted to the northeasterly direction. As a result, particulate matter started accumulating over Delhi and neighbouring areas.

A scientist from the Regional Meteorological Centre, Delhi, said there would be no immediate change in the situation though things were likely to start looking up from Monday afternoon. “The morning will remain foggy, but wind speed is likely to pick up from the afternoon. The anti-cyclone that has been affecting northwest India will also start to weaken and northwesterly winds will establish over the plains. There will be gradual improvement through Monday and, hopefully, Tuesday and Wednesday will be comparatively better,” said the official.