The city’s air quality index (AQI) started dipping again on Friday, causing several areas in the city and eastern and western suburbs to experience ‘poor’ air quality. Mumbai’s overall average AQI, however, stood at 179 (moderate).

The AQI scale categorises air quality as ‘good’ from 0-50, ‘satisfactory’ from 51-100, ‘moderate’ from 101-200, ‘poor’ between 201-300, ‘very poor’ from 301-400, and anything higher than 400 as ‘severe.’ Many areas in Mumbai recorded AQI levels above 200, causing a thick blanket of haze to form over many pockets of the city. The worst AQI in the city was at Malad West (see box) followed by Borivli East and Navy Nagar in Colaba.