Delhi enjoys a ‘good’ air day for the first time since July 2017
The last time Delhiites breathed such clean air was on July 31, 2017, when the AQI measured 47. Any reading of up to 50 on the index is considered to be an indicator of good quality air.Updated: Aug 18, 2019 17:48 IST
Thanks to intermittent rain and strong winds, with some help from anti-pollution measures put in place over the months by government agencies, the residents of Delhi on Saturday breathed the cleanest air in more than two years.
The Air Quality Index (AQI) value improved from 53 on Friday to 49, a level at which it is considered to be “good”. The last time Delhiites breathed such clean air was on July 31, 2017, when the AQI measured 47. Any reading of up to 50 on the index is considered to be an indicator of good quality air.
The AQI had never fallen below 50 on even a single day in 2018, when it had at best read “satisfactory.”
“The AQI dropped to less than 50 after a long gap, indicating that air quality was the cleanest. Such clean-air days are rarely seen in Delhi. It was mainly because of the rain that the air quality turned good,” said a senior Central Pollution Control Board (CPCB) official who didn’t want to be named.
The levels of the two most biggest polluters of Delhi – PM10 and PM2.5 – were also much below their daily permissible limits. PM10 and 2.5 are particulate matters of less than 10 and 2.5 microns in size that can enter the respiratory system and cause health complications.
While the daily permissible limit of PM10 (coarse naturally occurring dust particles) is 100ug/m3, at 4pm on Saturday the level of the pollutant was around 28ug/m3. The permissible limit of PM2.5 (finer particles that are typically emitted by vehicles and industries is 60ug/m3; its level dropped to 12ug/m3 around the same time.
Experts said that while rain and winds played a crucial role in helping improve air quality to its best in more than two years by washing and blowing away pollutants, it was also the cumulative outcome of the anti-pollution measures that have been put in place by the city authorities.
“A series of measures have been undertaken over the past two years including introducing PNG for industries, shutting down coal-based power plants, introducing BS-VI fuel among others. The overall air quality has improved,” said an official of the Delhi Pollution Control Committee who didn’t want to be named.
First Published: Aug 17, 2019 23:50 IST