Delhi's smoggy winter: 64% fine-particulate pollution comes from outside

During summers, 74% of Delhi's PM 2.5 pollution is caused by sources located outside Delhi

Delhi contributes no more than 36 per cent to its fine-particulate (PM 2.5) pollution during winters, with 64 per cent coming from sources outside the 56,800-sq-km area of the national capital region (NCR), according to a new study.

During the winter of 2016-17, the average concentration of PM 2.5 in Delhi-NCR was 168 microgram per cubic metre (μg/m3)–about three times higher than the national standard of 40 μg/m3 and about 16 times higher than the World Health Organization’s (WHO) tighter standard of 10 μg/m3 , said the study, released on August 16,