Dhaka, the overcrowded capital city of Bangladesh, has ranked fifth on the list of cities with the worst air quality with an AQI index of 154 at about 09:10am on Saturday.

Dhaka’s air was classified as ‘unhealthy’, according to the air quality and pollution city ranking.

Vietnam’s Hanoi, Thailand’s Chiang Mai, India’s Delhi and Egypt’s Cairo occupied the first four spots in the list, with AQI scores of 185, 178, 167 and 164, respectively.

An AQI between 151 and 200 is considered ‘unhealthy’ while 201-300 is ‘very unhealthy’ and 301-400 is considered ‘hazardous’, posing severe health risks to residents.

The AQI, an index for reporting daily air quality, informs people how clean or polluted the air of a certain city is and what associated health effects might be a concern for them.

The AQI in Bangladesh is based on five 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.