Dhaka, the overcrowded capital of Bangladesh, ranked second on the list of cities with the worst air quality, recording an AQI score of 252 at 9am on Monday.
The air was classified as 'very unhealthy' according to the air quality and pollution rankings.
Mongolia's Ulaanbaatar and Vietnam's Hanoi occupied the first and third spots on the list, with AQI scores of 255 and 244, respectively, reports UNB.
An AQI between 151 and 200 is said to be ‘unhealthy’ while 201 and 300 is considered ‘very unhealthy’, and 301 to 400 is ranked 'hazardous', posing serious health risks to residents.
In Bangladesh, the AQI is based on five criteria pollutants -- Particulate Matter (PM10 and PM2.5), NO2, CO, SO2 and Ozone.
Dhaka has long been grappling with air pollution issues. Its air quality usually turns unhealthy in winter and improves during the monsoon.
As per the World Health Organization (WHO), air pollution kills an estimated seven million people worldwide every year, largely as a result of increased mortality from stroke, heart disease, chronic obstructive pulmonary disease, lung cancer and acute respiratory infections.
