In a list released by the Central Pollution Control Board on Air Quality Index (AQI) of cities in India, Noida was the most polluted city on Sunday (January 14) with an AQI of 456. This was followed by Delhi (447), Baddi (438), Greater Noida (421), Faridabad (398), Ghaziabad (392), Ballabgarh (389), Saharsa (374), Chandigarh (370), Bhagalpur (368), and Gurugram (364).