Dhaka, Dec. 12 -- Dhaka, the capital of Bangladesh, ranked 10th among the world's most polluted cities on Friday morning, recording an AQI score of 167 at 9 am.

According to the Air Quality Index (AQI), Dhaka's air at that time fell into the 'unhealthy' category, posing health risks for residents.

Under the AQI scale, a reading of 50-100 is considered 'moderate', 101-150 'unhealthy for sensitive groups', 150-200 'unhealthy', 201-300 'very unhealthy', and 301+ classified as 'hazardous', which carries severe health risks.

India's Delhi, Vietnam's Hanoi and India's Kolkata topped the list, with AQI scores of 385, 255 and 246, respectively.

The AQI, an index for reporting daily air quality, informs people how clean or polluted the air of ...