Dhaka, the overcrowded capital of Bangladesh, ranked 14th on the list of cities with the worst air quality, recording an AQI score of 125 at 8:50 am on Friday.

The air was classified as ‘unhealthy for sensitive groups’, indicating a potential health risk, according to the AQI index.

When the AQI value for particle pollution ranges between 50 and 100, air quality is considered ‘moderate’, and unusually sensitive individuals should consider limiting prolonged outdoor exertion.

An AQI reading between 101 and 150 is considered ‘unhealthy for sensitive groups’, while 150 to 200 is labelled ‘unhealthy’. A reading between 201 and 300 is termed ‘very unhealthy’, and 301 or above is regarded as ‘hazardous’, posing serious health risks to residents.

Pakistan’s Karachi, India’s Delhi, and Vietnam’s Hanoi occupied the first, second and third spots on the list, with AQI scores of 291, 248 and 233 respectively.

The AQI, an index for reporting daily air quality, indicates how clean or polluted the air in a particular city is and what associated health effects may be a concern.

In Bangladesh, the AQI is calculated based on five pollutants: particulate matter (PM10 and PM2.5), nitrogen dioxide (NO₂), carbon monoxide (CO), sulphur dioxide (SO₂) and ozone.

Dhaka has long been grappling with severe air pollution. Air quality usually worsens in winter and improves during the monsoon season.

According to the World Health Organization (WHO), air pollution causes an estimated seven million deaths worldwide every year, mainly due to increased mortality from stroke, heart disease, chronic obstructive pulmonary disease, lung cancer and acute respiratory infections.