With an air quality index (AQI) score of 33, Dhaka's air quality has been reported as "good" this morning (July 31, 2022).

Despite the "good" air quality, the metropolis ranked 52nd in the list of world cities with the worst air quality at 10am.

An AQI between 0 and 50 is considered to be "good" while between 50 and 100 is "moderate".

Chile's Santiago, Peru's Lima and China's Shenzhen occupied the first three spots in the list, with AQI scores of 154, 128 and 126, respectively.

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.