Delhi topped the list of most polluted capital cities in the world in 2019, according to a new report which also revealed that 21 of the world's 30 most polluted cities are in India. According to the World Air Quality Report 2019 compiled by IQAir Air Visual, Ghaziabad is the most polluted city in the world, followed by Hotan in China, Gujranwala and Faisalabad in Pakistan and then Delhi in the fifth place. The 21 Indian cities which are in world's 30 most polluted cities, in the order of their ranking, are, Ghaziabad, Delhi, Noida, Gurugram, Greater Noida, Bandhwari, Lucknow, Bulandshahr, Muzaffarnagar, Baghpat, Jind, Faridabad, Coraut, Bhiwadi, Patna, Palwal, Muzaffarpur, Hisar, Kutail, Jodhpur and Moradabad. According to country-wise data, India ranked fifth in the world's most polluted countries with Bangladesh on top of the list followed by Pakistan, Mongolia and Afghanistan.