The densely populated capital of Bangladesh has once again topped the list of cities with the worst air quality in the world.
The Air Quality Index (AQI) in Dhaka was recorded at 174 at 10:20 am on Monday
India’s Delhi, Uzbekistan's Tashkent and Vietnam's Hanoi ranked second, third and fourth respectively, with AQI scores of 153, 147 and 145.
An AQI reading between 101 and 200 is considered ‘unhealthy’, particularly for sensitive groups. A reading between 201 and 300 is considered ‘very unhealthy’, while 301 to 400 is classified as ‘hazardous’, posing serious health risks.
The AQI is used by government agencies to report daily air quality and inform the public about pollution levels and possible health impacts.
In Bangladesh, the index is calculated based on five major pollutants — particulate matter (PM10 and PM2.5), nitrogen dioxide (NO₂), carbon monoxide (CO), sulphur dioxide (SO₂) and ozone.
Dhaka has long struggled with severe air pollution, with conditions typically worsening in winter and improving during the monsoon season.
Air pollution remains one of the leading global health risks. Exposure to polluted air increases the risk of heart disease, chronic respiratory illness, lung infections and cancer, according to multiple studies.
The World Health Organization (WHO) estimates that air pollution causes around seven million premature deaths worldwide each year, mainly due to stroke, heart disease, chronic obstructive pulmonary disease, lung cancer and acute respiratory infections.