22 of world's 30 most polluted cities are in India 22 of world's 30 most polluted cities are in India Last Updated: Wed, Mar 17th, 2021, 11:43:04hrs New Delhi: Twenty-two of the world's 30 most polluted cities are in India, with Delhi being ranked as the most polluted capital city globally, a new report said on Tuesday. The report is prepared by Swiss organisation, IQAir, in the form of the 'World Air Quality Report, 2020', which has released globally. The report, however, shows that Delhi's air quality improved by approximately 15 per cent from 2019 to 2020. It said that despite the improvement, Delhi ranked as the 10th most polluted city and the top polluted capital city in the world.