Air quality in the Capital stayed “very poor” on Thursday even as pollution levels in some parts of the city remained “severe” as fog engulfed the city again in the morning hours.
Although the overall Air Quality Index read 369, which is “very poor”, Lodhi Road had an AQI of 500 while IGI Airport touched 478 which are severe. Most other stations had very poor AQI.
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 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.
Other stations, however, had very poor AQI, which means from 300-400. Pusa Road had the AQI at 396, Dhirpur 329, Delhi University 398 and Pitampura 397.
As per the advisory, people with existing heart or lung diseases must avoid exertion when the air quality is “very poor”.
In the morning, the 24-hour rolling average of PM10 and PM2.5 touched very poor limits, according to System of Air Quality Weather Forecasting and Research (SAFAR) data. PM 10 was recorded at 334 and PM 2.5 at 183 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.
On Friday, heavy to dense fog can be expected in the morning followed by a clear sky during the day. The maximum and minimum temperature are expected to be around 24°C and 9°C, respectively. On Thursday, the maximum temperature was 23.9°C while minimum was 8.7°C, both normal for this time of the year.