Dhaka, the densely populated capital of Bangladesh, ranked thirteenth among the world’s most polluted cities on Sunday morning, recording an Air Quality Index (AQI) of 115 at 11:10 am.

Today's air was classified as "unhealthy for sensitive groups", referring to a health threat, according to the AQI index.

Bishek in Kyrgyzstan, Kathmandu in Nepal, Beijing in China occupied the first, third, and fourth spots on the list, with AQI scores of 197, 166, and 160 respectively.

AQI levels of 101–150 are ‘unhealthy for sensitive groups’, 151–200 is ‘unhealthy’, 201–300 is ‘very unhealthy’, and readings above 301 are considered ‘hazardous’, posing severe health risks.

The AQI, which reports daily air quality, informs residents how clean or polluted the air is and highlights potential health effects.

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

Dhaka has long struggled with air pollution. Air quality usually deteriorates in winter and improves during the monsoon season.

The World Health Organization (WHO) estimates that air pollution causes about seven million deaths worldwide each year, primarily from stroke, heart disease, chronic obstructive pulmonary disease, lung cancer, and acute respiratory infections.