Dhaka's air quality slipped back to the unhealthy zone this morning.
With an air quality index (AQI) score of 154 at 8:56am, Dhaka ranked 7th in the list of cities worldwide with the worst air quality.
An AQI between 151 and 200 is considered unhealthy while between 201–300 is very unhealthy, and 301–400 is hazardous, posing severe health risks to residents.
Thailand's Chiang Mai, Pakistan's Lahore and Saudi Arabia's Riyadh occupied the first three spots in the list, with AQI scores of 330, 175 and 165, respectively.
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. Breathing polluted air has long been recognised as increasing a person's chances of developing a heart disease, chronic respiratory diseases, lung infections and cancer, according to several studies.
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.
