Air quality in the Capital stayed “very poor” on Wednesday morning even as fog covered the city in the early hours.
According to forecast, the air quality may get fouler over the next couple of days.
The 24-hour rolling average of PM10 and PM2.5 touched poor and very poor limits respectively, according to System of Air Quality Weather Forecasting and Research (SAFAR) data, reading 346 and 174 microgram per cubic metre respectively. The Air Quality Index clocked 317 in very poor category on Wednesday.
“Cold winds from the Indo-Gangetic Planes are bringing in pollution to the Delhi region and as a result air is getting fouler. The air quality will keep getting worse till Thursday when PM2.5 is expected to touch 200 microgram per cubic metre,” Gufran Beig, programme director of SAFAR, which comes under the earth sciences ministry, had told HT.
PM2.5 and PM10 are ultrafine particles — the dominant pollutants in Delhi. The 24-hour acceptable levels of PM 2.5 and PM10 are 60 and 100 microgram per cubic metre, respectively.
As per SAFAR advisory, people with existing heart or lung diseases must avoid exertion when the air quality is “very poor”.
With patterns and directions changing, dense fog is expected to return to Delhi soon. “We have dense fog forecast for December 8 and 10. But this may persist today and December 9 too,” said a scientist at the Regional Weather Forecast Centre (RWFC).
The change in weather, in terms of dense fog, comes with the return of easterly winds. “There is also a cyclonic movement of air over the Bay of Bengal. The factors raise moisture in the air, which in cold climates can lead to fog,” a scientist said.
The minimum temperature on Wednesday morning was recorded at 11.2 degrees, which is two notches above average for this time of the year, a MeT official said.