All the residents of Bangladesh’s capital Dhaka are at health risk as the megacity ranked top among cities with the worst air quality on Tuesday morning.

It had an AQI score of 298 at 8:00am. The air was classified as ‘very unhealthy’ and in this state of air everyone may experience serious health effects, the UNB reported.

 When the AQI value is between 201 and 300, the entire population is more likely to be affected while children are advised to limit outdoor activities in this situation.

India’s Delhi and Mongolia’s Ulaanbaatar occupied the second and third positions in the list of cities with the worst air quality with AQI scores of 219 and 215 respectively.

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 has long been grappling with air pollution. Its air quality usually improves during monsoon.