Pakistan's Lahore and Thailand's Chiang Mai occupied the first and second spots on the list

File photo: Air pollution in Dhaka Mehedi Hasan/Dhaka Tribune

Dhaka's air quality is again in the unhealthy zone on Tuesday morning.

With an air quality index (AQI) score of 193 at 9:20 am, the capital of Bangladesh ranked third on the list of cities worldwide with the worst air quality.

Pakistan's Lahore and Thailand's Chiang Mai occupied the first and second spots on the list, with AQI scores of 212 and 206, respectively.

An AQI between 151 and 200 is considered unhealthy while 201–300 is very unhealthy, and 301+ is 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.

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