Crackers played a big role in pollution spike in Delhi-NCR: CSE

It said the pollution peak on Diwali undid the comparatively cleaner air trend achieved in the analysis period this year.

A 10-fold jump in PM 2.5 concentration between 5 pm and 1 am was noted due to bursting of firecrackers this year, the report said.

“The peak level between 1 am and 3 am was quite similar to the peak levels observed in 2018 on Diwali. This year’s Diwali was warmer and windier. However, in 2018, the peak pollution continued until 8 am, whereas this year, the peak showed a sharper fall after 3 am,” the report said.

Even with better wind condition leading up to Diwali in 2018, pollution levels were higher, meaning that the overall pollution load would have been more in days before Diwali last year.

Favourable weather conditions and emergency interventions to control air quality played an important role in reducing pollution in Delhi-NCR since September 15 and enabled quicker dissipation of pollution post-Diwali, the report said.