Dhaka, Nov. 28 -- Dhaka's air quality continued to be in the 'unhealthy' zone on Sunday morning.

With an air quality index (AQI) score of 122 at 9:45 am, Dhaka ranked 20th in the list of cities around the world with the worst air quality, reports UNB.

An AQI between 101 and 200 is considered 'unhealthy', particularly for sensitive groups.

Pakistan's Lahore, India's Delhi and Kolkata occupied the first, second and third spots in the list, with AQI scores of 454, 256 and 193, respectively.

An AQI between 201 and 300 is said to be 'poor', while a reading of 301 to 400 is considered 'hazardous', posing serious health risks to residents. In Bangladesh, the AQI score is based on five kinds of pollutants - particulate matter (PM10 and PM2.5)...