Air quality was categorised as "poor or very poor" on nearly 90 per cent of the total days in the four-month winter season this year, a study on Friday said and asserted that air pollution poses a serious threat to living standards in the national capital.
"Not a single day in the four-month-long winter season was noted under the 'Good' air quality category, while a whopping 89 per cent of the total days were either under the 'Poor' or 'Very Poor' air quality category," said a bulletin on 'Ambient Air Quality for Delhi' released by Centre for Environment and Energy Development (CEED).
"Six per cent of days are also observed with 'Severe' air quality. This poses serious threat to the living standards and public well-being of our national capital," the bulletin said.
The bulletin said 981 kg/m3 is the maximum average concentration of particulate matter (PM2.5) observed at the monitoring station of Delhi Technological University (DTU) located near Bawana industrial area on November 5 last year during high pollution smog-days in Delhi.
"This is 16 times higher than the prescribed limits of National Air Quality Standard of 60 ug/m3 for 24-hour average concentration of particulate matter (PM2.5)," it said.
The findings are based on data from 10 real-time air quality monitoring stations in Delhi, set up by Central Pollution Control Board (CPCB), during the last winter season between the months of November, 2016 and February, 2017.
"The report is not just an assessment of the existing levels of air pollution in Delhi, but is also a reflection of the levels of human exposure to air pollution," it said.
The study also revealed that the monthly mean values demonstrated a general downward trend from November to February.
The average concentration of particulate matter in the month of November was calculated to be 282.7 ug/m3 (the highest), while the monthly mean concentration during the rest of the winter season (December, January and February) was 224.57 ug/m3, 172.7 ug/m3 and 140.74 ug/m3 respectively.
The highest daily average concentration of PM2.5 in the month of November was 558 ug/m3 on November 7 last year, while in December, it was 300 ug/m3 recorded on 24th of the month.
In January and February, the highest daily average concentration of PM2.5 was recorded on January 1 (225 ug/m3) and February 28 (215 ug/m3) respectively, the bulletin said.
"The air quality of the city is unbreathable and is choking its residents, especially the vulnerable, causing a massive public health disaster. It is a crisis looming in our faces and we cannot turn a blind eye to it.
"This emergency situation demands emergency action. While keeping the urgency of the situation in mind, the Graded Response Action Plan (GRAP) approved by Supreme Court should immediately be ratified by the Government of NCT of Delhi, so that its implementation can start on ground," said Dimpy Suneja, Programme Officer of CEED.
The fact that the air quality in Delhi has plunged to dangerous levels, poses a major threat to public health and safety, he said while noting that every year millions of people face untimely death due to the increasingly polluted quality of air they breathe.
