Bangladesh’s capital Dhaka ranked third worst in the Air Quality Index (AQI) on Saturday morning.

It had an AQI score of 207 at 851 am. The air was classified as ‘very unhealthy’.  When the AQI score is between 201 and 300, this would trigger a health alert signifying that everyone may experience more serious health effects.

India’s Delhi and Bosnia Herzegovina’s Sarajevo occupied the top two positions in the list of cities with worst air with scores of 302, 241 and 210 respectively.

When the AQI score is between 201 and 300, every city dweller is likely to be affected.

But when the value is more than 300, the air quality is considered hazardous and everyone may experience more serious health effects.

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, the overcrowded megacity, has long been grappling with air pollution. The air quality usually improves during monsoon.