Dhaka, March 6 -- Dhaka, the densely populated capital of Bangladesh, ranked second among the world's most polluted cities on Friday morning, recording an Air Quality Index (AQI) of 286 at 11:53 am.

Today, the city's air was classified as 'Very unhealthy', indicating a serious health threat, according to the AQI report.

Lahore in Pakistan, Kolkata in India and Delhi in India occupied the first, third, and fourth spots on the list, with AQI scores of 328, 191, and 184 respectively.

In contrast, Batam in Indonesia recorded the world's cleanest air, with an AQI score of 0.

According to the AQI scale, a reading between 50 and 100 is considered 'moderate', with generally acceptable air quality, though sensitive individuals should limit pro...