Delhi no longer most polluted city; Gwalior, Allahabad top the chart in India
The national capital was ranked ninth worst city in the survey, with an annual average PM 2.5 measurement of 122.
May 12, 2016, 16:11 PM IST
The national capital was ranked ninth worst city in the survey, with an annual average PM 2.5 measurement of 122.
May 12, 2016, 16:11 PM IST