Dhaka, Sept. 29 -- Dhaka ranked 6th among the world's most polluted cities on Tuesday morning, recording an Air Quality Index (AQI) score of 162 at 10:40 am.

The air quality was classified as 'unhealthy', meaning the concentration of pollutants in the air had reached a level that could pose health risks to the general population, according to the AQI scale.

Indias Kolkata topped the list with an AQI score of 196.

Malaysia's Kuala Lumpur and Singapore of the Singapore ranked second and third, respectively, with AQI scores of 189 and 169.

According to AQI standards, a reading between 101 and 150 is considered 'unhealthy for sensitive groups', while 151 to 200 is classified as 'unhealthy'. A reading between 201 and 300 is considered 'ver...