Dhaka's air quality turns 'unhealthy' again Dhaka ranked 3rd worst in the Air Quality Index (AQI) on Friday morning. -Mostafizur Rahman

After showing a marked improvement in its quality for the last few days, Bangladesh's capital Dhaka ranked 3rd worst in the Air Quality Index (AQI) on Friday morning.

The mega city had an AQI score of 153 at 08:55am and its air quality was classified as 'unhealthy'. When the AQI scores between 151 and 200, some members of the general public may experience health effects and members of sensitive groups may start experiencing more serious health effects, reports UNB.

Pakistan's Lahore and India's Delhi occupied the first and second spots in the list of cities with AQI scores of 173 and 158 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 pollutant criteria - Particulate Matter (PM10 and PM2.5), NO2, CO, SO2, and Ozone (O3).