Dhaka has once again emerged as the world’s most polluted major city, with deteriorating air quality posing growing concerns for public health and everyday life. On Tuesday (6 October), Bangladesh’s capital recorded an Air Quality Index (AQI) score of 217, placing it in the ‘very unhealthy’ category, according to the air quality monitoring platform IQAir.
The reading indicates that the city’s air contained a level of pollution considered hazardous to human health, particularly for people who are more vulnerable to the effects of polluted air. Dust, vehicle emissions and other harmful airborne particles are among the factors that contribute to Dhaka’s persistent air quality problems.
According to IQAir’s global city ranking, Kuala Lumpur in Malaysia was the second-most polluted city on Tuesday, recording an AQI score of 194. India’s Kolkata ranked third with a score of 175, while Delhi also recorded 175 and was placed fourth. Singapore occupied fifth place with an AQI score of 161.
IQAir classifies AQI readings between zero and 50 as ‘good’, indicating relatively clean air. A score from 51 to 100 is considered ‘moderate’ or acceptable. When the reading reaches 101 to 150, the air is classified as ‘unhealthy for sensitive groups’. Scores between 151 and 200 are considered ‘unhealthy’, while readings from 201 to 300 fall into the ‘very unhealthy’ category. An AQI above 300 is classified as ‘hazardous’.
Dhaka’s score of 217 therefore places the city well inside the very unhealthy range. At such levels, prolonged exposure to polluted air can become a serious concern, particularly for children, older people and those with existing respiratory or cardiovascular problems.
Bangladesh’s AQI assessment takes several major pollutants into account. These include particulate matter such as PM10 and PM2.5, nitrogen dioxide (NO₂), carbon monoxide (CO), sulphur dioxide (SO₂) and ozone (O₃). Fine particulate matter is of particular concern because smaller particles can penetrate deep into the respiratory system.
Dhaka’s air pollution has several established sources. A report published in March 2019 by Bangladesh’s Department of Environment and the World Bank identified brick kilns, vehicle emissions and dust from construction sites as three major contributors to air pollution in the capital.
Construction activity and road dust can become especially problematic when loose dust is left exposed or is repeatedly stirred up by traffic. Vehicle emissions add another layer of pollution in the densely populated city, where large numbers of vehicles operate every day.
The health consequences of prolonged exposure to polluted air extend far beyond temporary discomfort such as coughing or breathing difficulties. According to the World Health Organization (WHO), air pollution is associated with serious conditions including stroke, heart disease, chronic obstructive pulmonary disease (COPD), lung cancer and acute respiratory infections.
The WHO estimates that air pollution contributes to around seven million deaths globally each year. Against that backdrop, Dhaka’s repeated presence near the top of global pollution rankings highlights the scale of the challenge facing the capital.
Improving the city’s air quality will require sustained attention to the sources of pollution, including emissions from vehicles, dust generated by construction and pollution associated with brick production. For residents, however, the latest AQI reading serves as another indication that polluted air remains a significant environmental and public health concern in Dhaka.
