Open burning of biomass behind hazy surroundings in Delhi, nearby regions, new study points out

A latest research on the air pollution in the national capital has found that open burning of biomass has been the largest contributor behind the hazy surroundings. The research found that open burning of biomass was the single largest contributor behind the hazy atmosphere in the city not only in the winter period (November-January) but also in the post-monsoon period that is between late October and November.

The crucial linkage of open burning of biomass with the hazy surroundings in the national capital and nearby regions was found in the research conducted by the scientists from IIT-Kanpur, IIT-Delhi, Indian Institute of Tropical Meteorology and Central Pollution Control Board (CPCB) among others.

As part of their methodology for the research, the scientists studied the composition of PM2.5 at two crucial sites in the national capital between the period of October 2019 and January 2020. The two sites namely- IIT-Delhi-Hauz Khan area and Pusa forest region- were studied and analyzed to gain insights about the sources of hazy air in the city.

The scientists, during their research, segregated four distinct periods of hazy lighting in the national capital namely post monsoon period(also known as agricultural burning time), haze 1, haze 2, and haze 3 period in the winter season. In all four distinct periods, the levels of PM 2.5 were different, the research found. Significantly, the scientists found that organic aerosols which are emitted during biomass burning played a dominant role in all the four haze periods. The study also said that after the conclusion of the post-monsoon (end of October to around mid-November) period, the haze was largely a result of open biomass burning particles likely emitted from “agricultural residue burning in the upwind states of Delhi.