Dhaka, Dec. 8 -- Dhaka has been ranked as the second most polluted city in the world with 'very unhealthy' air quality on Thursday morning.

Dhaka's air quality index (AQI) score was 215 at 9:15 am today (Thursday).

An AQI between 201 and 300 is said to be 'very unhealthy', while a reading of 301 to 400 is considered 'hazardous', posing serious health risks to residents.

Pakistan's Lahore and Mongolia's Ulaanbaatar occupied the first and third spots in the list, with AQI scores of 343 and 201, respectively.

An AQI between 101 and 200 is considered 'unhealthy', particularly for sensitive groups.

In Bangladesh, the AQI is based on five criteria pollutants -- Particulate Matter (PM10 and PM2.5), NO2, CO, SO2 and Ozone.

Dhaka has long be...