New Delhi/Noida, Oct. 17 -- An all-too-familiar haze has returned to the National Capital Region (NCR) on Thursday, cloaking Delhi and its suburbs in a thick blanket of pollution even before Diwali's firecracker emissions compound the crisis.

Data from the Central Pollution Control Board's Thursday bulletin delivered a stark reality check: the top eight most polluted cities in India were all in the NCR, painting a grim picture of what lies ahead as temperatures drop and meteorological conditions turn unfavourable in coming weeks.

Ghaziabad gained the notorious distinction of being India's most polluted town on Thursday, topped the list with an Air Quality Index (AQI) of 307 - categorised as "very poor." Ballabhgarh, near Faridabad, foll...