Dhaka's air quality turned "moderate" this morning (August 10, 2022).

With an air quality index (AQI) score of 68 at 9:30am, the densely populated metropolis ranked 22nd in the list of world cities with the worst air quality.

Saudi Arabia's Riyadh, Pakistan's Lahore and the United Arab Emirates' Dubai occupied the first three spots in the list, with AQI scores of 309, 153 and 151, respectively. 

An AQI between 50 and 100 is considered "moderate" with an acceptable air quality. However, there may be a moderate health concern for a very small number of people who are unusually sensitive to air pollution.

An AQI between 101 and 200 is considered "unhealthy", particularly for sensitive groups.

Similarly, an AQI between 201 and 300 is said to be "poor", while a reading of 301 to 400 is considered "hazardous", posing serious health risks to residents.

AQI, an index for reporting daily air quality, is used by government agencies to inform 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.