Dhaka ranked seventh among 126 cities worldwide on Tuesday in a list of the most polluted cities, recording an Air Quality Index (AQI) score of 166, which indicates unhealthy air quality.
According to the air quality index published by Swiss-based monitoring organisation IQAir on Tuesday, October 20, India’s Delhi topped the list with an AQI score of 201, indicating very unhealthy air quality.
Pakistan’s Lahore ranked second with a score of 200, followed by Kuala Lumpur in Malaysia with 190. Mumbai, another Indian city, ranked fourth with a score of 181, while Singapore City stood fifth with a score of 168.
Under the AQI scale, scores from 0 to 50 indicate good air quality, while 51 to 100 are considered moderate. Scores between 101 and 150 are unhealthy for sensitive groups, and readings from 151 to 200 indicate unhealthy air. Scores between 201 and 300 are classified as very unhealthy, while readings above 300 are considered hazardous.
In Bangladesh, air quality assessments take into account five major pollutants: particulate matter (PM10 and PM2.5), nitrogen dioxide (NO₂), carbon monoxide (CO), sulphur dioxide (SO₂) and ozone (O₃).
A 2019 report by the Department of Environment and the World Bank identified brick kilns, vehicle emissions and dust from construction sites as three major sources of air pollution in Dhaka.
The World Health Organization has linked air pollution to an increased risk of stroke, heart disease, chronic obstructive pulmonary disease, lung cancer and acute respiratory infections. It estimates that air pollution contributes to around seven million deaths worldwide each year.