When the AQI value for particulate pollution is between 101 and 150, the air quality is considered ‘unhealthy for sensitive groups’, 150 and 200 ‘unhealthy’, between 201 and 300 ‘very unhealthy’ while a reading of 301+ is considered ‘hazardous’, posing a serious health risk to residents.
In Bangladesh, the AQI is based on five criteria pollutants – particulate matter (PM10 and PM2.5), NO2, CO, SO2 and ozone.