New Delhi: According to the latest World Health Organisation's (WHO) urban air quality database, Delhi is now free from tag of the most polluted city in the world.
The national capital was ranked ninth worst city in the survey, with an annual average PM 2.5 measurement of 122.
In 2014, the WHO had rated Delhi as the most polluted city in the world in terms of PM 2.5 levels.
However, six Indian cities - Gwalior, Allahabad, Patna, Raipur, Ludhiana, and Delhi – make to the list of among the most polluted cities in the world.
The dirtiest air was recorded at Zabol in Iran, Gwalior and Allahabad are a close second and third in terms of PM 2.5. Whereas, Patna and Raipur stand at 6th and 7th respectively.
PM 2.5 is associated with more serious health impacts than PM 10.
WHO used data from various government and research organisations for the database, it's based on ground measurements of annual mean concentrations of particulate matter (PM 10 and PM 2.5) and "aims at representing an average for the city or town as a whole, rather than for individual stations. Years of measurements range from 2010 to 2015, unless the latest available data was older," the report said.
WHO's latest report indicates that Delhi has made a considerable improvement in tackling air pollution.