Dhaka ranks second worst polluted city

Dhaka has been ranked second-most polluted in the latest list of world cities with the worst air quality being categorised as 'very unhealthy'.

The city recorded a fall in air pollution with its air quality index (AQI) hitting 225 around 9am on Monday.

Meanwhile, Pakistan’s Lahore occupied the first spot with a score of 321 which is classified as ‘Hazardous’.

Air quality in this ‘hazardous’ range triggers health warnings of emergency conditions by media outlets.

China’s Wuhan occupied the third spot with a score of 220 which is 'very unhealthy'.

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.

Dhaka has long been grappling with air pollution issues. Its air quality usually turns unhealthy during winter and improves during monsoon.

However, last week, Dhaka’s air quality slightly improved with a score of 75 ranking 40th worst in the Air Quality Index (AQI) due to rains triggered by the depression in the Bay of Bengal on December 6.