New Delhi, Nov. 12 -- Delhi-NCR's winter air pollution is once again drawing attention, with the region remaining under a blanket of smog days after Diwali. While firecrackers added significantly to the pollution load during the festive period, they are only one part of a larger problem involving vehicle emissions, industrial activity, construction dust, regional pollution and weather conditions.

An assessment by the Indian Institute of Tropical Meteorology (IITM), Pune, found that firecrackers contributed 71.1% of the PM2.5 concentration in Delhi's air between 1 am and 9 am on November 9, immediately after Diwali celebrations. The contribution was 43.4% during the same hours on November 8 and 5.6% on November 7, The Indian Express repor...