Dhaka tops list of cities with most polluted air

Dhaka has once again topped the list of cities with the worst air quality this morning.

With an air quality index (AQI) score of 251 at 8:55am today, Dhaka ranked first in the list of cities with the worst air.

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.

India's Delhi, Uzbekistan's Tashkent and India's Mumbai occupied the second, third and fourth spots with an AQI of 223, 166, and 165 respectively.

Meanwhile, an AQI between 101 and 150 is considered "unhealthy", particularly for sensitive groups.

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.