Dhaka, Jan. 12 -- Dhaka, the densely populated capital of Bangladesh, ranked second among the world's most polluted cities on Monday morning, recording an Air Quality Index (AQI) of 285 at 9:43 am.

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

Cairo in Egypt, Chengdu in China, and Delhi in India occupied the first, third, and fourth spots on the list, with AQI scores of 300, 244, and 241 respectively.

According to the AQI scale, a reading between 50 and 100 is considered 'moderate', with generally acceptable air quality, though sensitive individuals should limit prolonged outdoor exertion. AQI levels of 101-150 are 'unhealthy for sensitive groups', 151-200 is ...