Code deep red: Air quality levels ‘severe’ across Delhi on Tuesday
NEWDELHI:Air quality levels were “severe” yet again on Tuesday morning. Coded deep red, “severe” is a dangerous marker in the air quality index (AQI) that can make even healthy adults sick.
The System of Air Quality and Weather Forecasting and Research (SAFAR) showed the AQI at 500 for all of Delhi as well as most of the individual monitoring stations.
As the day progressed, the smog lifted a little but pollutants dispersed marginally in few areas.
SAFAR last week had forecast that air quality would likely improve slowly from November 2 as the Diwali impact starts to wear off.
The pollution level is classified as “severe” if the AQI is between 401 and 500. In China, such a situation is called “red alert”.
Its continuance for three consecutive days calls for desperate measures such as shutting down schools and offices, closing down industries and power plants and rationing of vehicles on roads.
Only NSIT Dwarka, Shadipur and IHBAS stations of the Central Pollution Control Board (CPCB) had air quality ranging from very poor to poor, the rest continued to show “severe” readings.
SAFAR put their 24-hour averages (rolling) at 315 and 468 micrograms per cubic metre, respectively, around 7pm, both in the severe category.
According to Hindustan Times monitoring of pollution across Delhi, the city had the worst air quality in Punjabi Bagh, RK Puram, Shantipath and Anand Vihar with the AQI reaching 500.
At 10 in the morning, Anand Vihar recorded PM10 (particulate matter 10 micrometers or less in diameter) at 793µg/m3 (microgram per cubic meter), while the PM2.5 clocked 472µg/ m3. At 7pm, PM 10 levels reached 1,330 µg/m3.
The prescribed standards of PM 2.5 and PM 10 are 60 and 100, respectively. Anything beyond that can harm the respiratory system as the ultra-fine particulates can embed deep into the lungs and enter the bloodstream.
Diwali fireworks pushed pollution in Delhi to a dangerous level, the worst in three years. It turned the air highly toxic due to a deadly cocktail of harmful respirable pollutants and gases, engulfing the city with a cover of thick smog that triggered health alarms.