Study says biomass is New Delhi’s largest contributor to winter pollution

A study has revealed that biomass burning from neighbouring regions is a major contributor to New Delhi’s winter pollution, Outlook India reports.

Published in the journal Nature Sustainability, the research suggests that urban emissions of black carbon from fossil fuel combustion are not always the predominant generators of pollution in cities like New Delhi.

“Black carbon aerosols are damaging to human health and their levels are higher in New Delhi than in many other megacities,” said August Andersson, from Stockholm University in Sweden.

“During fall and winter, the levels of polluting air particles in New Delhi can reach ten times the limit recommended by the World Health Organization (WHO).

“To determine the environmental effects of black carbon in this highly populated city, it is crucial to quantify the contributions from the key emissions sources.”

The researchers collected air samples from New Delhi during 2011 and analysed their black carbon content by creating carbon isotope signature profiles of each of the samples to identify the source of the particles.

Relative contribution from fossil fuel combustion peaked during rainy summers and the contribution from biomass burning peaked during the dry fall and winter months.

“The wintertime regional influx of black carbon into New Delhi suggests that to efficiently combat severe air pollution, it is necessary to not only mitigate the urban emissions, but also regional-scale biomass emissions, including agricultural crop residue burning,” said Andersson.

Read the latest issue of Nature Sustainability here.