, Oct. 25 -- Dhaka has ranked fifth on the list of cities worldwide with the worst air quality with an AQI score of 169 at 9:02 am this morning.

Dhaka's air was classified as 'unhealthy', according to the air quality index.

Pakistan's Lahore, India's Delhi and Kolkata and China's Beijing occupied the first four spots on the list, with AQI scores of 360, 270, 189 and 178, respectively.

When the AQI value for particle pollution is between 50 and 100, air quality is considered 'moderate', between 101 and 150 is considered 'unhealthy for sensitive groups', between 151 and 200 is 'unhealthy', between 201 and 300 is said to be 'very unhealthy', while a reading of 301+ is considered 'hazardous', posing serious health risks to residents.

The ...