40% of PM 2.5 pollutants in Delhi originate outside NCR: study

The level of pollution caused by fine particulate matter (PM 2.5) in Delhi will continue to exceed normal limits even if all emissions inside the city were stopped, as over 40 per cent of it originates outside the NCR, a study has found.
About 60 to 80 per cent of ozone concentration in Delhi was also attributed to sources outside the city in the report, prepared jointly by TERI and the University of California, San Diego.
"This study finds that in-house sources in Delhi contribute about 32 per cent (10-65 per cent) of the air pollution in Delhi, while NCR (National Capital Region) sources (other than Delhi) contribute an additional 25 per cent (13-37 per cent).

"The remaining 43 per cent (25-63 per cent) is the background due to sources outside of NCR," the report says.
The analyses and solutions suggested in the report released here today at the World Sustainable Development Summit organised by TERI, are based on a "synthesis" of studies and reports done over the last decade.
Even if all emissions from Delhi were to be stopped, the PM (particulate matter) levels would still exceed the standards at several locations in the city, mainly due to higher contributions from outside regions to Delhi's air quality, it says.

The safe limits of PM 2.5 and PM 10, microscopic particles that can enter and embed deep into the lungs and subsequently the bloodstream, are 60 and 100 micrograms per cubic metre respectively.

It also offers 10 "scalable solutions" to reduce air pollution across the country, focusing on regional cooperation and a multi-scale and cross-sectoral coordination including the launch of a 'National Clean Air Mission'.
"Switch to low-sulphur fuels (10 ppm) and implement Bharat VI (similar to Euro VI) standards for engine emissions...Implement wall-to-wall paving of streets and vacuum cleaning of roads; enforce ban on open burning of solid waste; manage waste and recovery of methane from landfills," are among the suggestions.
India's efforts to meet its Paris INDCs (Intended Nationally Determined Contributions) will significantly reduce air pollution, the report states.
The monitored annual average PM 2.5 concentrations in Delhi have varied between 60 mg/m3 to 140 mg/m3, as measured by different agencies, such as Central Pollution Control Board (CPCB), Delhi Pollution Control Committee (DPCC), and SAFAR, during the last few years.