After Delhi breathed its cleanest air this year on Monday, the national capital has moved back to its unhealthy air quality, thanks to lack of rain and wind.
Delhi’s air quality index(AQI) on Tuesday morning was recorded at 169, considered unhealthy.
Monday’s heavy overnight rain achieved what this year’s monsoon couldn’t — produce a “good air” day, the first in October since the index began in 2015. The city’s average AQI on Monday entered the “good” zone (below 50) for the first time in 14 months.
On Sunday, Delhi’s AQI was 355.
A western disturbance over southern Afghanistan and easterly winds over northwest India had contributed to the prevailing weather conditions over the capital on Monday, according to the IMD.
At 7 pm on Sunday at the Anand Vihar monitoring station, PM 10 levels dropped to 48 µg/m3 down from a high of 346 µg/m3 at 4 am. At Mandir Marg, PM 10 levels fell to 23 µg/m3 at 7 pm from 472 µg/m3 at 4 am. PM2.5 levels at Mandir Marg were nearly zero at 7 pm, as opposed to a figure of 349 µg/m3 at 4 am.
“For the past one month, I have been tweeting data of air quality in Delhi. Pollution has increased in the last 3-4 days, and it is due to stubble burning in neighbouring states. Farmers in neighbouring states are compelled to burn stubble as their governments are doing nothing for them (towards stopping stubble burning),” Kejriwal said in an event organised to lay the foundation stone of a new government hospital in Shalimar Bagh.
Data from the Central Pollution Control Board, which started measuring AQI from 2015, shows good air days are rare in Delhi. Not a single such day was reported in 2015, 2016 and 2018. Rarer still are good air days outside the monsoon season, with just one recorded since 2015, prior to Monday.
In 2017, there were two “good air” days, on July 30 and 31. Two days were reported in 2019 as well — August 18 and 19.
Last year, Delhi saw five good air quality days — one in March following the total Covid lockdown and four in August.