With an air quality index (AQI) score of 183 at 9:04 am today, Dhaka ranked 3rd on the list of cities worldwide with the worst air quality.

Iraq's Baghdad and India's Delhi occupied the first and second spots, with AQI scores of 191, and 189 respectively.

AQI between 101 and 150 is considered 'unhealthy', and between 201 and 300 is said to be 'very unhealthy', while a reading of 301+ is considered 'hazardous', posing serious 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.

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.