Dhaka, May 4 -- Dhaka ranked fourth among the world's most polluted cities on Monday morning, recording an Air Quality Index (AQI) of 137 at 08:55 am.

The air quality was classified as 'unhealthy for sensitive groups', indicating increased health risks for vulnerable populations, particularly children, the elderly, pregnant individuals, and those with heart or lung conditions, according to the AQI scale.

Baghdad in Iraq, Chiang Mai in Thailand and Manama in Bahrain occupied the top three spots, with AQI scores of 212, 147 and 142 respectively.

According to AQI standards, a reading between 101 and 150 is considered 'unhealthy for sensitive groups', 151 to 200 'unhealthy', 201 to 300 'very unhealthy', while levels above 301 are deemed 'h...