A day after Diwali, Delhi chokes as air quality plummets. Check out what other cities woke up to

Delhi registers an AQI of 567, which is categorised as 'hazardous'; Lucknow, Kolkata and Mumbai also among the worst affected

A day after Diwali, while Bengaluru and Mysuru woke up to relatively cleaner air as against cities such as Delhi, Lucknow, Kolkata and Mumbai which saw air quality plummet to 'hazardous' to 'unhealthy' levels.

Delhi was the most polluted major city in India and the world on Tuesday, with an AQI of 567, which is categorised as 'hazardous', as per data from IQAir portal at 9 am.

The major pollutant in the national capital was particulate matter (PM) 2.5 which was measured at 321 µg/m³.

In view of the deteriorating air quality in Delhi, the Commission for Air Quality Management has invoked Stage II of the Graded Response Action Plan (GRAP) across Delhi-National Capital Region.

Under Stage II of GRAP, several curbs and intensified actions are in place, including daily mechanical or vacuum sweeping and water sprinkling on identified roads, preferably before peak traffic hours, to control dust.

The air quality in Kolkata (AQI 194), Lucknow (AQI 190) and Mumbai (AQI 172) was categorised as 'unhealthy'.

While air pollution levels rise during the festival due to bursting of firecrackers, weather patterns significantly influence how quickly the air clears up.

Bengaluru, which is witnessing moderate rain and cloudy weather, registered an AQI of 80, categorised as 'modetate'. The PM2.5 level in the city was 26 µg/m³.

Chennai, which saw heavy rain on Monday under the influence of an upper air cyclonic circulation over South Andaman sea and adjoining southeast Bay of Bengal, registered an AQI of 54 on Tuesday morning.

Here is a list of 10 Indian cities and their AQI levels.