Delhi sees worst November air on record

Delhi saw its worst November air this year since the Central Pollution Control Board (CPCB) started measuring the air quality index (AQI) in 2015.

The month saw 11 “severe” air quality days, the highest since 2015. The average AQI was 376, beating the record of 374 in 2016. 

Experts said the extended monsoon resulted in high stubble burning counts in the first two weeks of November and meteorological parameters, including low wind speed and low mixing layer height, caused pollutants to get trapped in the atmosphere.

In contrast to November, 2021 recorded the cleanest October since 2015.

Dipankar Saha, former head of CPCB’s air laboratory said that “November first half is historically critical in all years, but this year, it continued in the second half too. It may be due to depressions in east and western areas, which did not allow free air flow downwards”.

“The emission sources for any defined area more or less remains the same throughout the year. However, the concentration varies with the season. November being the transition phase, the air quality in north India is always problematic because of lowering of atmospheric boundary layer, wind speed, temperature and local action plans implementations,” he added. 

Anumita Roychowdhury, executive director research and advocacy of Centre for Science and Environment, said that a combination of calm winter conditions, entrapment of local pollution in the region and the tipping over due to the spike in stubble burning post-Diwali has led to the prolonged severe smog episode.

“This is a grim reminder of the fact that the comprehensive plan for multi-sector action that was notified in 2018 has not been further revised and implemented at scale and speed across all districts of NCR. We cannot fix this problem only with temporary emergency measures,” she said.