Firecrackers' contribution to PM2.5 pollution on Diwali night was significantly higher than what was seen on days preceding it, according to a study. The IITM assessment has provided a breakdown of the relative contributions of various sources to PM2.5, including vehicular emissions, biomass-burning, waste-burning, secondary aerosols, and dust. Firecrackers contributed 71.1% to PM2.5 levels, while Punjab Minister Barinder Kumar Goyal questioned stubble burning blame.