Dhaka ranked fifth yesterday in the AirVisual Index of cities around the world with the worst air quality.
In the real-time air quality ranking, Dhaka scored 164 yesterday and classified as “unhealthy”, according to AirVisual.
On Tuesday, Dhaka remained on top of the air quality index for some time, scoring 361, and was classified as “hazardous”.
Bangladesh, one of the most densely-populated countries in the world, has been struggling with air pollution for a while, and Dhaka continuously ranks among the world's most polluted cities.
Many environmental experts blamed the pollution on construction of metro rail and other major projects. They also identified brick kilns, vehicles run on fuel containing higher levels of sulphur, as well as construction work as primary sources of air pollution.
On February 9, green activists, including Poribesh Bachao Andolan (Poba) and Nagorik Odhikar Sangrakkhan Forum, voiced deep concerns that around 90 percent of Dhaka residents are affected by serious dust pollution and urged the authorities concerned to take effective measures.
They also said the intensity of dust pollution rises during winter due to road digging and delayed disposal of wastes, causing various respiratory, allergy and skin diseases.
The High Court has ordered the director general of Department of Environment (DoE) to take steps to conduct mobile court drives twice a week against those responsible for air pollution in the city.
A new study that uses data from the Global Burden of Disease Project has found that ambient air pollution shortens an average Bangladeshi's life by 1.87 years.
The study also suggested that better air quality could lead to a significant extension of human lifespan around the world.
Currently, the World Health Organization (WHO) estimates that worldwide seven million people die every year from exposure to such pollution with most deaths occurring in low and middle-income countries, mainly in Africa and Asia.
US environmental experts developed the Air Quality Index (AQI) which is divided into six categories, indicating increasing levels of health concern.
An AQI value over 300 represents hazardous air quality, and below 50 the air quality is good.
The index is based on the five criteria of pollutants regulated under the Clean Air Act: ground-level ozone, particulate matter, carbon monoxide, sulfur dioxide and nitrogen dioxide.
Worldwide, ambient particulate matter ranks as the sixth leading risk factor for premature death, according to the 2018 “State of Global Air” report.
These risks are acute in Dhaka, said the report.