Dhaka's air quality continued to be in the "moderate" zone this morning, thanks to the torrential rain for the past few days and traffic yet to return to its usual form after Eid holidays.

With an air quality index (AQI) score of 68 at 8:25 am, Dhaka ranked 29th in the list of cities worldwide with the worst air quality.

India's Delhi, Pakistan's Lahore and China's Beijing occupied the first three spots on the list, with AQI scores of 137, 133 and 114, respectively.

An AQI between 50 and 100 is considered 'moderate' with an acceptable air quality. However, there may be a moderate health concern for a very small number of people who are unusually sensitive to air pollution.

Besides, an AQI between 150 and 200 is considered 'unhealthy', AQI between 201 and 300 is said to be 'very unhealthy', while a reading of 301+ is considered 'hazardous', posing serious health risks to residents.

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.

Air pollution consistently ranks among the top risk factors for death and disability worldwide.

As per the World Health Organization (WHO), air pollution kills an estimated seven million people worldwide every year.