Dhaka ranked fourth on the list of cities worldwide with the worst air quality with an AQI score of 185 at 8:54 am on Thursday morning.

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

India’s Delhi and Pakistan’s Lahore and Karachi occupied the first, second and third spots in the list, with AQI scores of 415, 366 and 219, respectively, UNB reports.

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.