Dhaka's air quality continued to be in the 'very unhealthy' zone on Wednesday morning. With an air quality index (AQI) score of 210 at 9:55 am, Dhaka ranked second in the list of cities around the world with the worst air quality. India’s Mumbai and Pakistan’s Lahore occupied the first and third spots, with AQI scores of 221, and 204, respectively. Read: Air pollution 2nd biggest cause of deaths in Bangladesh in 2019, cost about 3.9-4.4% of GDP: World Bank An AQI between 101 and 200 is considered 'unhealthy', particularly for sensitive groups. Similarly, an AQI between 201 and 300 is said to be 'poor', while a reading of 301 to 400 is considered 'hazardous', posing serious health risks to residents. AQI, an index for reporting daily air quality, is used by government agencies to inform people how clean or polluted the air of a certain city is, and what associated health effects might be a concern for them. Read: Effects of Air Pollution on Unborn Children, Neonates, Infants In Bangladesh, the AQI is based on five criteria pollutants -- Particulate Matter (PM10 and PM2.5), NO2, CO, SO2 and Ozone.