Dhaka ranked second in the list of cities across the world with the worst air quality on Tuesday.
According to AirVisual, Dhaka showed an average air quality index (AQI) score of 180 at 8:43pm. The air quality was classified as "unhealthy" at the time.
Residential areas like Bashundhara and Uttara showed AQI scores of 199 and 184, respectively.
Mongolia's Ulaanbaatar, Vietnam's Hanoi, and India's Mumbai occupied the first, third and fourth spot in the list of cities with worst air quality with AQI scores of 198, 167, and 162, respectively.
Earlier on Tuesday morning, Dhaka showed an average air quality index (AQI) score of 152 at 11:52am, taking the 9th position on the ranks of cities with worst air in the world. At that time, residential areas like Bashundhara and Baridhara showed AQI scores of 159 and 152, respectively.
The AQI, an index for reporting daily air quality, informs people how clean or polluted the air of a certain city is, and what associated health effects might be a concern for them.
When the AQI value is between 151 and 200, every city dweller may begin to experience health effects. Members of sensitive groups may experience more serious health effects in this situation.
In Bangladesh, the AQI is based on five criteria pollutants -- Particulate Matter (PM10 and PM2.5), NO2, CO, SO2, and Ozone (O3).
The Department of Environment has also set national ambient air quality standards for these pollutants. These standards aim to protect against adverse human health impacts.
As one of the most densely populated countries in the world, Bangladesh has been struggling with air pollution for a long time. Dhaka continuously ranks among the world's most polluted cities.
Brick kilns, vehicles run on fuel containing higher levels sulphur, as well as construction work, have all been identified as major sources of air pollution.
Air quality further declines during the dry months – from October to April – but improves during the monsoon.
