BATHINDA: The summer of 2022 was not only unusually hot but also uncharacteristically high in particulate pollution, especially in north India. High PM 2.5 levels were observed across multiple cities and regions as the pollution has not been confined to a few megacities or a specific region — it has turned into a widespread national problem.
This has emerged from the analysis of summer air quality undertaken as part of the air quality tracker initiative of the urban lab at the Centre for Science and Environment (CSE). Summer days from March 1 to May 31 have been considered for the analysis, as rains had set in during June in several regions. As the availability of real-time air quality data has improved in several regions with the expansion of the air quality monitoring systems, it has become possible to assess the regional differences and understand the unique regional trends.
“This analysis identifies the unique patterns of pollution across all regions and puts a spotlight on a large number of towns and cities that do not get policy attention. Summer particulate pollution spikes due to arid conditions, high summer heat and temperature, and more airborne dust particles that travel long distances compounding the problem from local sources,” says Anumita Roychowdhury, executive director, research and advocacy, CSE.
“This air quality tracker initiative has helped to benchmark the summer air quality for peer-to-peer comparison within each region and understand the inter-regional differences that need to inform policy action. Several regions experienced high particulate pollution when heat wave conditions were also widespread and intense,” says Avikal Somvanshi, senior programme manager at the Urban Lab.
This data 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 356 official stations under the Continuous Ambient Air Quality Monitoring System (CAAQMS) spread across 174 cities in 26 states and Union territories.
As per findings, North India is the most polluted, with Delhi-NCR being the summer pollution hotspot. Summer average PM2.5 for North India stood at 71 µg/m³, the highest among all the regions. East India with 69 µg/m³ summer average was the second worst. West India (54 µg/m³) and Central India (46 µg/m³) also recorded summer level access of 40 µg/m³. Northeast India (35 µg/m³) and South India (31 µg/m³) were the cleaners compared to other regions.
Daily peak pollution was highest in east India, with cities of Bihar recording the highest levels. It was found that the average pollution this summer was higher than the previous summer.
North India has recorded a staggering 23 per cent increase in seasonal PM2.5 level compared to the previous summer based on an average of cities that have valid daily PM2.5 concentration data of both summers. Smaller cities and towns dominate the most polluted list for this summer.
The way forward: Says Roychowdhury: “Overall, seasonal pollution is expected to be highly variable due to the impact of local and regional pollution, and meteorological and climatic impacts that need to inform policy making. Due to arid and heat conditions and growing desertification, summer months usually witness high dust impacts. But the dust is also a carrier of toxic substances from combustion sources including vehicles, industry, power plants, and the burning of waste. While the local nature of this problem needs to be investigated in all regions, this requires significant tightening of action to control emissions from each pollution source as well as massive efforts to combat desertification, improve soil stabilisation, and green-walling through afforestation, and reduce the heat island effect in cities.”