Delhi: Pollution this year on verge of breaking 17-year smog record of 2016
The levels of particulate matter in Delhi-NCR, which shot up nearly eight times above the safe standards on Sunday, dropped to six times above the permissible limit by Monday 8pm.delhi Updated: Nov 13, 2017 22:53 IST
One more day of “severe” levels of air pollution, and Delhi could break the record of the infamous 2016 smog, considered the worst in 17 years. Over the past seven days, the city has been reeling under “severe” levels of pollution, similar to conditions in November 2016.
But Met officials have predicted some relief ahead. They have forecast that, by Tuesday afternoon, the air quality is expected to return to “very poor” levels, considered normal during this time of the year.
The levels of particulate matter in Delhi-NCR, which shot up nearly eight times above the safe standards on Sunday, dropped to six times above the permissible limit by Monday 8pm.
This improvement was, however, not reflected in the day’s average AQI, which stood at 460, the same as Sunday. The AQI is a 24-hour average, experts said. The actual improvement would be better reflected in the falling level of particulate matter.
“We expect the pollution to hit ‘very poor’ category by Tuesday once again. This improvement was expected by Sunday, but the sudden changes in local weather delayed the process,” said Gurgan Beig project director of SAFAR, maintained by the Union ministry of earth sciences.
An official from Central Pollution Control Board (CPCB) said that the only good news this year has been that peak pollution levels has not been as harsh as 2016. While last year, the AQI touched 497 on November 6, this year the peak of 486 was hit on November 9.
Pollution levels first entered the “severe” zone on November 7. Officials said that pollution levels have been improving since November 9. The relief, however, was short-lived as the air turned foul again from Saturday afternoon. This time the AQI touched 460. But since Sunday, it has again started improving, officials said.
The changing wind pattern has helped in the process, officials said. While high altitude winds that usually bring in pollutants from outside have slowed, surface level winds that help to flush out local pollutants are gathering speed.
“The speed of surface level winds, which had dropped from 7kmph on Friday to around 2kmph on Saturday evening, has again increased to 6kmph on Monday,” said a Met official.
The level of PM10 dropped to 539ug/m3 around 8pm on Monday, from 712ug/m3 on Sunday afternoon. A PM10 value above 500 is considered an emergency.
PM2.5 levels which had hit 480ug/m3 on Sunday has also dropped to 362 on Monday. A PM2.5 value above 300 denotes emergency levels. It is expected to come down to 245ug/m3 by Tuesday.
First Published: Nov 13, 2017 22:52 IST