64% of Delhi's winter pollution load from external sources, study shows

New Delhi: Around 64 per cent of Delhi's winter pollution load comes from outside the capital's boundaries, with "burning of agricultural waste" and "burning for heating and cooking needs" being the major sources, according to a study released on Thursday.

Transport (12 per cent), dust (seven per cent), and domestic biomass burning (six per cent) are the major sources of locally-generated pollution in the city in winter (October 15 - January 15), the study by Council on Energy, Environment and Water (CEEW) said.

The researchers used data from publicly available air quality forecasts, including Delhi's Air Quality Early Warning System (3-day and 10-day), Decision Support System for Air Quality Management in Delhi (DSS), and UrbanEmissions.Info.

"Sixty-four per cent of Delhi's winter pollution load comes from outside its boundaries. Biomass burning of agricultural waste during the stubble burning phase and burning for heating and cooking needs during peak winter are the major sources of air pollution from outside the city, according to UrbanEmissions.Info," the study said.

Data gathered from UrbanEmissions.Info showed that open fires (31.68 percent), dust (15.84 percent) and transport (11.88 percent) were the major sources of pollution in the "stubble burning" phase between October 15 and November 15 last year.

In the "post-stubble burning" phase from November 15 to December 15, use of biomass for household heating and cooking (17 percent), dust (17 percent) and transport (16 percent) contributed the most to the air pollution in the capital.

Interestingly, use of biomass for household heating and cooking (31.68 percent) emerged as the major contributor in the peak winter phase between December 15 and January 15, followed by dust (15.84 percent) and transport (14.85 percent).

The researchers called for surveys in residential areas across NCR to explore the prevalence of biomass usage for heating and cooking purposes.