New Delhi: Air quality in the Capital worsened on Wednesday as pollution levels in various parts of the city reached “severe” proportions.
Although the overall Air Quality Index read 379, which is “very poor”, Pusa Road had the AQI at 404, Dhirpur 441, Delhi University 458, IGI Airport 438 and Pitampura 431. These are all in the severe category. The monitoring station at Lodhi Road recorded a maximum AQI of 500.
Air pollution level is classified as severe if the AQI is between 401 and 500. China declares a “red alert” at this level.
Severe AQI for three consecutive days is met with desperate measures such as shutting down of schools and offices, closing down industries and power plants and rationing of vehicles on the roads.
SAFAR has advised people to avoid all outdoor physical activity. People with heart or lung diseases, senior citizens, and children should remain indoors and keep activity levels low when air quality turns “severe”, it said.
People with existing heart or lung diseases such as asthma, congestive heart disease, or ischemic heart disease should avoid heavy exertion when the air quality is “very poor”.
In the morning, 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. These, too, became fouler as the day progressed clocking 408 and 222 microgram per cubic metre.
PM2.5 and PM10 are ultrafine particles that are 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.
According to forecasts, the air-quality may get fouler over the next couple of days.
“Cold winds from the Indo-Gangetic plains 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 200g/m³,” Gufran Beig, programme director of SAFAR, which comes under the earth sciences ministry, told HT.
With patterns and directions changing, dense fog has returned to Delhi. Officials predict dense to very dense fog on Thursday morning.
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 was recorded at 11.2°C, which is two notches above average for this time of the year, a MeT official said. The maximum was recorded at 24.3°C, which is normal. On Thursday, the maximum and minimum temperature will be around 25°C and 12°C, respectively.