Under fire from the Supreme Court, the Commission for Air Quality Monitoring (CAQM) is reportedly dusting off the IIT Kanpur-TERI report on Delhi-NCR air pollution sources and will discuss it over the next few days.
ET gathers that the ‘High Resolution Multi Pollutants Emissions Inventory of National Capital Region (NCR)’ shows air pollution sources vary in the capital and NCR.
In Delhi, road dust and transport are the biggest PM 10 and PM 2.5 pollutants, whereas in NCR, industrial pollution dominates. Stubble fires contribute 7-10% to PM 10 and PM 2.5 in NCR.
The 2013 IIT Kanpur source apportionment research of PM 2.5 and PM10 found that road dust contributed 56% to PM 10 and 38% to PM 2.5, while vehicular pollution contributed 9% and 20%.
The new study shows road dust and traffic pollution are the main culprits of Delhi’s poor air quality.
Road dust contributed 42% to PM 10 load analysis, followed by transport at 25%. The ongoing construction in Delhi adds 15% PM to the air. Vehicle tail pipe/exhaust emissions account for 47% of PM 2.5 emissions.
Transport accounts for 41% of SO2 and 78% of NOx emissions.
Two-wheelers emit 31% of PM 2.5 and 31% of PM 10 in the NCR region, followed by three-wheelers (28%), trucks (18%), and buses (7%). According to the study, buses (34%) emit the most NOx in NCR, followed by two-wheelers (20%) and trucks (10%).
Road dust dominates Delhi, yet it’s PM 2.5 share is only 20%. According to 2021-22 data, power plants contribute 8%. Diesel generators contribute 4% to residential 5%.
NCR mix: In the NCR areas of Uttar Pradesh, Punjab, Haryana, and Rajasthan, industry, stone crushers, and farm residue burning are the most significant contributors.
The caveat here is that significant corrective action has been taken since 2022, particularly in terms of coal-based power plants, and this figure may now be lower.
According to data from 2021-22, 41% of PM 10 emissions in NCR are attributed to industry emissions, 22% to stone crushers, and 12% to road dust.
In PM 2.5 inventories in NCR, it is once again the industry leading, accounting for 44%, followed by stone crushers at 19%. Farm fires stand out here, accounting for up to 10% of emissions, matching the 9% from the transportation sector.
Viewfinder: Experts aware of the report’s findings assess that the strong focus on road dust mitigation is beginning to pay off.
The vehicular pollution story, however, is different.
Reason one: Registered vehicle population in Delhi has grown from about 3 million in 1998 to more than 12 million in 2019.
Reason two: While the BS VI emission norms are certainly a big improvement, it is only by 2027 that we will see its full impact when only vehicles running on this emission norm will ply on roads.
