An all-India winter air quality analysis done by Centre for Science and Environment (CSE) says particulate pollution spiked and stayed elevated with varying intensity across all regions during the winter of 2021-22 (15 October to 28 February).
Even though the overall regional averages of PM2.5 levels were lower than the previous winter in most regions, the winter smog episodes recorded severe spikes in several regions. Peak pollution was alarmingly high and synchronized, despite large distances within the regions – especially in the northern and eastern plains.
The analysis has been done for the 2021-22 winter air quality tracker initiative of CSE’s Urban Data Analytics Lab. “Clearly, the winter pollution challenge is not limited to mega cities or to one specific region; it is now a widespread national problem that requires urgent and deliberate action at a national scale” says Anumita Roychowdhury, Executive Director, Research and Advocacy, CSE.
“This requires quicker reforms and action in key sectors of pollution – vehicles, industry, power plants and waste management to bend the annual air pollution curve and daily spikes,” she added.
“As availability of real time air quality data has improved in several regions with expansion of the air quality monitoring systems, it has become possible to assess the regional differences and the unique regional trends. This can help to inform the regional clean air action,” says Avikal Somvanshi, programme manager, Urban Data Analytics Lab, CSE.
This air quality tracker initiative has helped to benchmark the winter air quality for peer-to-peer comparison within each region and inter-regional differences.
This analysis is based on publicly available granular real time data (15-minute averages) from the Central Pollution Control Board’s (CPCB) official online portal Central Control Room for Air Quality Management. The data is captured from 326 official stations under the Continuous Ambient Air Quality Monitoring System (CAAQMS) spread across 161 cities in 26 states and union territories.
Says Roychowdhury: “The widely divergent trend in pollution levels across regions is strongly influenced by local geoclimatic conditions, meteorology and the intensity of pollution. But the emerging trend points towards a national air quality crisis. While the regions are battling to meet the national ambient air quality standards, winter conditions are aggravating the problem further”.
“Even though the pandemic conditions have arrested the trend overall trend in most regions, there is still a mixed trend. Despite having a relatively lower annual average pollution levels the peak pollution during winter can spike. This indicates the influence of cool and calm winter conditions and also the regional influence,” she added.
Adds Somvanshi: “While cities require their respective clean air action plans for controlling local pollution, the effort will have to be scaled up for the region to control pollution from widely dispersed sources across the urban and rural landscape”.
“The multi-sector plan has to address vehicles, industry, power plants, household pollution, waste burning and more. This granular tracking of regional and local pollution needs to inform policy making and the compliance framework for air quality management to meet the clean air targets”, he added.
