In Pics | 10 most polluted cities in the world (2022)

Delhi and Kolkata have been listed among the top 10 most polluted cities in the world in terms of exposure to hazardous fine particulate matter (PM2.5), according to a report published by the US-based research organisation Health Effects Institute (HEI), providing a comprehensive and detailed analysis of air pollution and global health effects for over 7,000 cities.

India's national capital Delhi has topped the list of the world's most polluted cities. The report showed that Delhi has the highest average level of fine PM2.5 among the world's most polluted cities. Delhi reported an average annual exposure of 110 µg/m3, said the report. µg/m3 refers to microgram per cubic metre. Credit: AFP Photo

Kolkata is the second most polluted city in the world in terms of exposure to hazardous fine particulate matter (PM2.5). Kolkata reported an average annual exposure of 84 µg/m3. Credit: Reuters Photo

Nigeria's Kano city was ranked third with an average annual exposure of 83.6 µg/m3. Credit: Reuters Photo

Lima, the capital of Peru, was in the fourth position reporting an average annual exposure of 73.2 µg/m3. Credit: AFP Photo

The capital and largest city of Bangladesh, Dhaka reported an average annual exposure of 71.4 µg/m3 and stood fifth on the list. Credit AFP Photo

The world's most populous island, Jakarta, was ranked sixth with an average annual exposure of 67.3 µg/m3. Credit: AFP Photo

Seventh on the list was Lagos in Nigeria. The city reported an average annual exposure of 66.9 µg/m3. Credit: AFP Photo

With an average annual exposure of 63.6 µg/m3, Pakistan's Karachi was positioned eighth on the list. Credit: Reuters Photo

China's capital Beijing stood ninth on the list with an average annual exposure of 55.0 µg/m3. Credit: AFP Photo

Accra in Ghana rounds off the top 10 list of most polluted cities in the world. Accra reported an average annual exposure of 51.9 µg/m3. Credit: Reuters Photo