After showing a marked improvement in its quality for the last few days, Bangladesh's capital Dhaka ranked worst again in the Air Quality Index (AQI) on Monday, reports UNB.
The mega city had an AQI score of 173 at 08:41am and its air quality was classified as 'unhealthy'.
When the AQI scores between 151 and 200, some members of the general public may experience health effects and members of sensitive groups may start experience more serious health effects.
Indonesia's Jakarta and United Arab Emirates's Dubai occupied the first and second spots in the list of cities with AQI scores of 167 and 161 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.
In Bangladesh, the AQI is based on five criteria pollutants - Particulate Matter (PM10 and PM2.5), NO2, CO, SO2, and Ozone (O3).
Dhaka's air remains mostly acceptable during monsoon from June to October.