Dhaka's air quality was "moderate" on Saturday morning, thanks to rain on Friday night.
With an air quality index (AQI) score of 98 at 8:52am, the capital of Bangladesh ranked 12th among cities worldwide with the worst air quality.
An AQI between 50 and 100 is considered moderate with acceptable air quality. However, there may be a moderate health concern for a very small number of people who are unusually sensitive to air pollution.
Chile's Santiago, South Africa's Johannesburg and Pakistan's Karachi occupied the first three spots in the list, with AQI scores of 171, 165 and 154, respectively.
An AQI between 101 and 200 is considered unhealthy, particularly for sensitive groups.
Similarly, an AQI between 201 and 300 is said to be poor, while a reading of 301 to 400 is considered hazardous, posing serious health risks to residents.
In Bangladesh, the AQI is based on five criteria 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.
Air pollution consistently ranks among the top risk factors for death and disability worldwide. Breathing polluted air has long been recognized as increasing a person's chances of developing heart disease, chronic respiratory diseases, lung infections and cancer, according to several studies.
According to the World Health Organization (WHO), air pollution kills an estimated seven million people worldwide every year, largely as a result of increased mortality from stroke, heart disease, chronic obstructive pulmonary disease, lung cancer and acute respiratory infections.
