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. The air quality usually improves during monsoon.
Last month, the High Court issued a nine-point directive to bring down air pollution level in Dhaka and ordered the Department of Environment (DoE) to conduct mobile court drives twice a week to take legal action against those responsible for air pollution in the capital.
The court also directed the Public Administration Ministry to appoint five executive magistrates for DoE within one month for conducting mobile courts.