Dhaka ranked 5th among the world's most polluted cities on Thursday morning, recording an Air Quality Index (AQI) score of 174 at 10:25am.
The air quality was classified as ‘unhealthy’, meaning the concentration of pollutants in the air had reached a level that could pose health risks to the general population, according to the AQI scale.
Pakistan's Lahore topped the list with an AQI score of 355, followed by India's Delhi at 271 and Kolkata at 208.
According to the AQI scale, readings of 101-150 are considered unhealthy for sensitive groups, while scores of 151-200 indicate unhealthy air quality. Readings of 201-300 are classified as very unhealthy, and scores above 301 are considered hazardous, posing serious health risks.
The AQI measures daily air quality and indicates pollution levels and their potential effects on public health.
In Bangladesh, air quality is assessed based on five major pollutants: particulate matter (PM10 and PM2.5), nitrogen dioxide (NO2), carbon monoxide (CO), sulphur dioxide (SO2) and ozone.
The World Health Organization estimates that air pollution causes around seven million deaths worldwide each year, primarily from stroke, heart disease, chronic obstructive pulmonary disease, lung cancer and acute respiratory infections.