Delhi and Varanasi are among the 14 Indian cities that figure in a list of world's 20 most polluted cities in terms of particulate matter PM2.5 levels in 2016. PM2.5 includes pollutants like sulfate, nitrate and black carbon, which pose the greatest risk to human health. According to data released by the World Health Organisation (WHO), other Indian cities that registered very high levels of PM2.5 pollutants were Kanpur, Faridabad, Gaya, Patna, Agra, Muzaffarpur, Srinagar, Gurgaon, Jaipur, Patiala and Jodhpur. They were followed by Ali Subah Al-Salem in Kuwait and a few cities in China and
Mongolia.
The data also said, nine out of 10 people in the world breathe air containing high levels of pollutants.
In terms of PM10 levels, 13 cities in India figured among the 20 most-polluted cities. WHO has called upon member-countries in its Southeast Asia Region to aggressively address the double burden of household and outdoor air pollution. It said, the region accounts for 2.4 million of the seven million premature deaths caused by household and outdoor air pollution together globally every year.