Mumbai, Oct. 21 -- Amid Diwali festivities, the overall Air Quality Index (AQI) in Mumbai deteriorated significantly, entering the 'poor' category today.

According to experts, this is the worst air quality logged in the city since the withdrawal of monsoon on October 10.

An AQI between 0-50 is considered good, 51-100 is satisfactory, 101-200 is moderate, 201-300 is poor, 301-400 is very poor, and 401-500 is severe.

Several parts of the city recorded air quality index (AQI) in the 'very poor' category today, with the Air Quality Early Warning System showing the highest reading of 341 at IMD Colaba station at 5 am.

A 'very poor' AQI was also recorded in Nandadeep Garden-Bandra Traffic Junction (313), Bapista Garden Mazagaon (305) early to...