Dhaka, Feb. 25 -- Dhaka, the densely populated capital of Bangladesh, ranked first among the world's most polluted cities on Wednesday morning, recording an Air Quality Index (AQI) of 277 at 8:18 am.

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

Delhi in India, Lahore in Pakistan, and Karachi in Pakistan occupied the second, third and fourth spots on the list, with AQI scores of 241, 241, and 141 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', 15...