Study finds northern India PM2.5 sources

• The study examines PM2.5 composition and oxidative potential in five locations: urban and roadside locations in Delhi, rural and industrial peripheries, and a suburban site in Kanpur.
• The study finds that local emission sources and atmospheric processes dominate particulate matter pollution.
• In Delhi, PM2.5 is dominated by ammonium chloride and organic aerosols from vehicular emissions, residential heating, and fossil fuel oxidation.
• The study highlights that PM2.5 oxidative potential is primarily influenced by organic aerosols from incomplete combustion of biomass and fossil fuels, particularly from traffic and residential sources.
• Hydrocarbon-like organic aerosols originate from fresh vehicular tailpipe emissions, with the highest average concentrations recorded at the urban roadside site in Delhi.
• The study also finds that the oxidative potential of PM2.5 in Indian cities is among the highest globally, exceeding levels in Chinese and European cities by up to five times.