India’s Delhi, Bishkek of Kyrgyzstan occupied the second and third places with an AQI of 193 and 190 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.

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.