Delhi was the most polluted city in India in 2022 with PM 2.5 levels more than double the safe limit and the third highest average PM10 concentration, according to an analysis of Central Pollution Control Board data. PM2.5 pollution in the national capital has reduced by over 7 per cent in four years, from 108 micrograms per cubic metre in 2019 to 99.71 micrograms per cubic metre in 2022, the report by NCAP Tracker said.