Photo: Mehedi Hasan/Dhaka Tribune

Malaysia's Kuching and Kuala Lumpur occupied the first and third spots respectively

Dhaka, Bangladesh's capital city has been ranked second worst in the Air Quality Index (AQI).

Dhaka had a score of 190 at 8:21am, indicating that the quality was unhealthy on Thursday morning.

Malaysia's Kuching and Kuala Lumpur occupied the first and third spots respectively.

When the AQI value is between 101 and 200, there is an increased likelihood of adverse effects and aggravation to the heart and lungs among general public, particularly for sensitive groups.

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). The Department of Environment has also set national ambient air quality standards for these pollutants. These standards aim to protect against adverse human health impacts.

Dhaka, one of the most densely populated cities in the world, has been battling air pollution for a long time.

The air quality generally worsens during summer and shows signs of improvement during monsoon when the dust settles.