Dhaka has once again featured prominently among the world’s most polluted cities, with deteriorating air quality posing growing concerns for public health. The Bangladeshi capital recorded an Air Quality Index (AQI) score of 173 on Wednesday (7 October), placing it third on the global list monitored by Swiss air-quality organisation IQAir.
An AQI score of 173 falls within the ‘unhealthy’ category, meaning exposure to the air can pose health risks to the wider population, particularly those who are more vulnerable to pollution.
According to IQAir’s index, Kuala Lumpur in Malaysia topped the list on the day with an AQI score of 210, categorised as ‘very unhealthy’. Singapore ranked second with a score of 176. Dhaka followed in third place, while India’s Delhi and Pakistan’s Lahore occupied fourth and fifth positions with scores of 165 and 164 respectively.
The AQI scale provides an indication of how polluted the air is and the potential health implications. A score between zero and 50 is considered ‘good’, while 51 to 100 is classified as ‘moderate’ or ‘satisfactory’. When the score reaches between 101 and 150, the air is considered unhealthy for sensitive groups.
A score of 151 to 200 falls into the ‘unhealthy’ category, while 201 to 300 is classified as ‘very unhealthy’. Any reading above 300 is considered ‘hazardous’, indicating a severe level of air pollution.
In Bangladesh, AQI measurements take into account several major pollutants, including particulate matter such as PM10 and PM2.5, nitrogen dioxide (NO₂), carbon monoxide (CO), sulphur dioxide (SO₂) and ozone (O₃). Among these, fine particulate matter is a significant concern because the tiny particles can penetrate deep into the respiratory system.
Dhaka’s air pollution has several long-standing sources. A joint report by Bangladesh’s Department of Environment and the World Bank in March 2019 identified brick kilns, vehicle emissions and dust from construction sites as three major contributors to air pollution in the capital. The concentration of these pollutants can fluctuate depending on weather, traffic, construction activity and other environmental conditions.
The health consequences of prolonged exposure to polluted air can be serious. According to the World Health Organisation (WHO), air pollution is associated with an increased risk of stroke, heart disease, chronic obstructive pulmonary disease, lung cancer and acute respiratory infections. The WHO estimates that exposure to air pollution contributes to around seven million deaths worldwide every year.
Dhaka’s position on the latest pollution ranking therefore reflects a wider urban and public-health challenge rather than simply a daily change in an index. Persistent pollution can affect everyday life, while children, older people and those with existing respiratory or cardiovascular conditions may face greater risks.
Reducing pollution will require sustained action against its major sources, including emissions from vehicles, dust generated by construction and pollution associated with brick production. Better control of these sources, alongside effective enforcement of environmental regulations, remains essential to improving air quality in the capital.
