Delhi topped a real-time list of the world's most polluted cities compiled by Swiss group IQAir, which put the national capital's AQI at 565, followed by 277 in the Pakistani city of Lahore. Kolkata (185) was third on the list, followed by Mumbai (173), Kuwait City (165), Baghdad (164), Dhaka (162), Jakarta (158), Doha (153) and Wuhan(153).