It found that controlling human-generated emissions in the heavily polluted region encompassing Delhi and neighboring states could reduce local PM2.5 concentrations by approximately 60% and lower the national average by 10%.
New Delhi: A study by National Institute of Advanced Studies (NIAS) has proposed dividing India into 16 air-quality management regions, called “airshedem”, to implement targeted pollution control measures based on local geography and emissions.
Researchers identified India’s 16 distinct airshedems by analysing over two decades of climate data (2000–2023), satellite-derived pollution estimates, emission inventories and machine learning. In contrast, AS-7’s pollution primarily comes from intensive coal and mineral mining, thermal power generation and automobile. Airshedem-7 (AS-7) is one of the central and southern Indian airsheds, according to the study. The researchers simulated an emission-control scenario where anthropogenic emissions were shut off only in AS-2. This targeted intervention cut PM2.5 concentrations in AS-2 by 60%, reduced pollution in neighbouring regions by 5% to 17%, and dropped the national average by 10% (from 33 to 30 micrograms per cubic metre). Researchers found that even with all local human-caused emissions shut off in the model, AS-2’s background PM2.5 remained high at 21 micrograms per cubic metre. Pollution transported from neighbouring countries contributed roughly 5 micrograms per cubic metre to the region’s background concentration. “Controlling anthropogenic emissions within the critically important airshedem-2 alone could reduce PM2.5 concentrations by around 70% locally, 40% across the Indo-Gangetic Plain, and 10% at the national scale.
“The characteristics of these regions reveal pronounced inequalities in pollution levels and sectoral emission contributions, where two of 16 airshedems, covering 23% of the landmass contribute 50% of the national PM2.5 and nitrogen oxide (Nox) source loads, with the residential, transportation and industrial sectors being the primary contributors,” said the study. The study, “Airshedem-Based Mitigation as a Pathway to Cleaner Air in India” by Ummed Singh Saharan and Gufran Beig, noted that AS-2’s elevated emissions stem from dense population, extensive agriculture, industrial and urban development, heavy transport, residential biofuels and crop burning. Thus, this study presents the multidimensional framework beyond traditional climatology and environ-geographical parameters to include socio-economic and cultural factors, making a conceptual advancement over existing approaches,” said Beig.
To ensure practical pollution-control planning, the framework also integrates factors like land use, population density, economic activity, geology, public health, and administrative boundaries. It is characterised by extensive forest cover and significant mining activity.