Dhaka ranks world's fourth-most polluted city

Dhaka's air quality index (AQI) was recorded at 155 at 9:23am Friday, once again making the capital's air fourth-most polluted in the world.

Iraq's Bagdad and China's Beijing occupied the first and third spots, with AQI scores of 471 and 171 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.

Governmental organizations utilize the AQI, an indicator for monitoring daily air quality, to let the public know how clean or polluted the air in a particular city is and what potential health impacts they should be aware of.

The AQI in Bangladesh is based on five criterion pollutants: ozone, NO2, CO, SO2, and particulate matter (PM10 and PM2.5).

In Dhaka, air pollution has always been an issue. Typically, its air quality worsens in the winter and improves in the monsoon season.