Unb, Dhaka

Dhaka yesterday yet again ranked first among cities with the worst air quality, in the Air Quality Index (AQI). The Bangladeshi capital had an AQI score of 202 at 8:13 am -- which is classified as “very unhealthy”. Thailand’s Chiang Mai and China’s Shenyang occupied the second and third positions with AQI scores of 192 and 165 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 201 and 300, the entire population is likely to be affected, according to the index.

In Bangladesh, the AQI is based on 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.

Heavy air pollution has contributed to Dhaka being one of the least livable cities in the world, but following the nationwide shutdown to prevent widespread transmission of the novel coronavirus, the air quality had shown signs of improvement. At 7:30am on March 29, it had an AQI score of 91, far lower than its usual score.