Delhi’s post-diwali air hazardous, but last 3 years were even worse

NEWDELHI: At 11am Monday, concentration of PM2.5 in Delhi crossed the “severe” level. By 8pm, it reached 279µg/m³. The permissible limit for the pollutant is 60µg/m³. However, the Delhi pollution control committee (DPCC), said the peak PM2.5 level on post-diwali day was 30% lower than 2018.

According to CPCB data, the 24-hour average AQI till 4 pm on Monday was 368. In 2018, Delhi recorded “very poor” air with an AQI of 390 the day after Diwali. In 2017, it was “severe” with AQI at 403. In 2016, the day after Diwali was also ‘severe” at 445 AQI. Also, air quality remained dangerously high for a week immediately after Diwali in these years. In 2015, the AQI was 360.

Delhi chief minister Arvind Kejriwal Monday praised citizens for showing restraint while bursting crackers. “Yesterday (Sunday) till about 8:30 pm, I was happy. But, post that people in Delhi did burn a few crackers. Nevertheless, pollution figures reveal that pollution was the lowest in last five years on Diwali night,” said Kejriwal. He said a lot of crackers were burnt neighbouring cities such as Ghaziabad, Gurugram, Noida and Faridabad, which impacted Delhi.

Delhi environment minister Kailash Ghalot tweeted,“…sustained efforts of Delhi Govt... has yielded these results.”

DPCC analysed the 24-hour average values of various pollutants between 6 am on Diwali day to 6 am on post-diwali day. “The peak PM 2.5 levels observed at 12am on Diwali night this year was 1070 µg/m³ against peak level of 1560 µg/m³ in 2018, a significant reduction of about 30%,” it said. PM10 level came down by 25%. “The peak level of PM10 this year at 1 am on Diwali night was 1391 µg/m³ against peak of 1859 µg/m³ recorded last year.”

The Centre for Science and Environment (CSE) said pollutants “dissipated faster” this year. “This was a warmer and windier Diwali than 2018. Last year, peak pollution continued until 8 am on post-diwali day, this year, the peak showed a sharper fall after 3 am,” said an analysis by Anumita Roychowdhury, executive director-research and advocacy, CSE.

PM2.5 levels in the week before Diwali this year were lower too with air mostly remaining “poor”. In 2018, there were a couple of “severe” days and many in the “very poor” category. CSE said the bursting of crackers had undone the favourable weather factor and that stronger action is needed arrest the deterioration.

RK Puram NSIT Dwarka