, Oct. 14 -- Dhaka has ranked fifth on the list of cities worldwide with the worst air quality with an AQI score of 159 at 8:59 am this morning.

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

Pakistan's Lahore, India's Delhi and Kolkata and Qatar's Doha occupied the first, second, third and fourth spots on the list, with AQI scores of 221, 194, 187 and 162, 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 s...