Delhi has topped the list of the most polluted cities in the world in a recent study conducted by environment NGO Greenpeace India.
The national capital was ranked first among 62 polluted cities in the report, Global Air Pollution 2018, a statement from the organisation said.
The report will officially be released on Tuesday.
The report accompanies an extended online interactive display of the world's most polluted cities, allowing further exploration of air quality across different regions and subregions in 2018, it said.
"The real-time status of all included locations, together with many more, can also be explored through the IQAir AirVisual Air Quality Map, which brings together live air quality readings in one accessible place," the NGO said.
The report measures the air quality in terms of PM2.5 data as aggregated through the IQAir AirVisual platform in 2018, it said.