World Health Organization has thought that,“India is home to four of the five cities in the world with the worst air pollution. The dirtiest air was logged at Zabol in Iran, which agonises from months of dust storms in the summer. 

Next Four are Indian cities as - Gwalior, Allahabad, Patna and Raipur. 
While, in the year 2014,the Capital of India –New Delhi, has recorded as the n0. 1 position, but after two years it is in the no. ninth worst city.

Maria Neira, Head of public health, environmental and social determinants of health at the WHO, praised India's government for developing a national plan to deal with the problem when others have been unable to.