Pollution spiked during odd-even due to crop burning, says CSE analysis

The CSE released its assessment after studies by other agencies said that odd-even did not help reduce pollution. The CSE study is based on the air quality data collected between April 15 and 30 — when the restriction was in place — and NASA satellite pictures.

Improvement in Delhi’s air quality during the odd-even restriction was overshadowed by forest fires and agricultural stubble burning in the neighbouring states, the Centre for Science and Environment said.

A man covers his face on a smoggy day, at Connaught Place in New Delhi.(HT File Photo)

The CSE released its assessment after studies by other agencies said that odd-even did not help reduce pollution. The CSE study is based on the air quality data collected between April 15 and 30 — when the restriction was in place — and NASA satellite pictures.

“The analysis of air quality data shows that air pollution took a dip during the first 10 days of the scheme but registered a sudden spike from April 22 onwards. Further, investigation and analysis of NASA satellite pictures has exposed massive crop fires in Punjab and Haryana that started around April 19 which could be the reason behind the rise in pollution levels. Forest fires in Uttarakhand added to the pollution load,” a CSE statement said.

According to the CSE’s analysis, pollution levels declined during the initial phase of odd-even for the first nine days — between April 15 and April 23. The average PM2.5 level during the first nine days was 24% lower than the average of the previous fortnight, CSE said.

“A distinct and sudden spike of pollution after April 23, when PM2.5 increased by as much as 92% and NO2 by 47%. The air quality worsened by up to 16% by April 26,” the CSE report says.

CSE looked at NASA satellite imagery and found that before the odd-even scheme and during the first few days, there was almost no crop fire in Punjab and Haryana.

“But April 21 onwards, there was a sudden spurt in crop fires that became widespread and intense from April 23 onwards. April 26 was particularly bad. During the spike, pollution increased despite high wind speed,” the report says.

CSE lambasted agencies that said odd-even did not improve Delhi’s air quality. “Poor air quality analysis can lead to irresponsible interpretation by industry. This lack of clarity has made it a convenient narrative for the auto industry to claim in the Supreme Court that vehicles do not contribute to pollution,” it said.