Dhaka's air quality remains in the ‘unhealthy' zone this morning. With an air quality index (AQI) score of 192 at 9:20 am today (January 18, 2023), the capital of Bangladesh ranked fourth in the list of world cities with the worst air quality.

An AQI between 151 and 200 is said to be ‘unhealthy’ while 201 and 300 is considered ‘very unhealthy’, and 301 to 400 is considered 'hazardous', posing serious health risks to residents.

Kyrgyzstan’s Bishkek and Pakistan’s Karachi and Lahore occupied the first three spots with an AQI of 236, 233, and 205 respectively.

Read more: Dhaka's air quality stays 'unhealthy'

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 in winter and improves during the monsoon.

As per the World Health Organization (WHO), air pollution kills an estimated seven million people worldwide every year, largely as a result of increased mortality from stroke, heart disease, chronic obstructive pulmonary disease, lung cancer and acute respiratory infections.

Read more: No respite from 'unhealthy' air in Dhaka