Dhaka ranked the worst world city in the Air Quality Index on Tuesday morning even though light rains drenched the capital and elsewhere. The city's Air Quality Index (AQI) recorded scores of 244 around 09.25am and its air quality was still classified as ‘ very unhealthy’. Read: Air pollution 2nd biggest cause of deaths in Bangladesh in 2019, cost about 3.9-4.4% of GDP: World Bank Dhaka’s air quality usually turns unhealthy during the winter and improves during monsoons. Pakistan's Lahore and India's Delhi occupied the next two spots, with AQI scores of 191, and 190, respectively. An AQI between 101 and 200 is considered 'unhealthy', particularly for sensitive groups. Read: Hydraulic horns to be banned in Dhaka in 2 months, says environment minister 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. In Bangladesh, the AQI is based on five criteria pollutants -- Particulate Matter (PM10 and PM2.5), NO2, CO, SO2 and Ozone.