Delhi did not see single good air quality day this winter

New Delhi: Delhi did not see a single “good” air quality day during the four-month long winter period, said a study on Friday. Air quality was categorised as ‘poor or very poor’ on nearly 90 per cent of the total days in the four-month winter season. Six per cent of the days also saw ‘severe’ air quality.

“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 the Centre for Environment and Energy Development.

The findings are based on data from 10 real-time air quality monitoring stations in Delhi, set up by the Central Pollution Control Board (CPCB), during the last winter season between the months of November 2016 and February 2017.

The bulletin added that the maximum average concentration of PM (particulate matter) 2.5 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 was 981 ug/m3.

This is 16 times higher than the prescribed limits of the National Air Quality Standard of 60 ug/m3 for a 24-hour average concentration of PM 2.5.

The study also revealed that the monthly mean values demonstrated a general downward trend between November and February. The average concentration of particulate matter in the month of November was calculated to be 282.7 ug/m3 (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.

“This poses serious threat to the living standards and public well-being of our national capital,” the statement said.