Dhaka Among World's Four Most Polluted Cities on Friday

Dhaka's air quality was classified as ‘very unhealthy’ on Friday morning, with an Air Quality Index (AQI) score of 203 at 8:40am.

With this reading, the capital ranked fourth among the world's most polluted cities, according to the AQI ranking.

A ‘very unhealthy’ air quality level means everyone, regardless of their health condition, may experience more serious health effects from air pollution. Even short-term exposure can cause discomfort and affect people's health.

Pakistan's Lahore topped the list with an AQI score of 456, followed by India's Delhi at 251 and Kolkata at 221.

On Thursday, Dhaka ranked fifth among the world's most polluted cities, recording an AQI score of 174 at 10:25am.

According to the AQI scale, readings between 101 and 150 are considered unhealthy for sensitive groups, while scores from 151 to 200 indicate unhealthy air quality. Readings between 201 and 300 are classified as very unhealthy, while scores above 301 are considered hazardous and pose serious health risks.

The AQI measures daily air quality by indicating pollution levels and their potential effects on public health.

In Bangladesh, air quality is assessed based on five major pollutants: particulate matter (PM10 and PM2.5), nitrogen dioxide (NO2), carbon monoxide (CO), sulphur dioxide (SO2) and ozone.

The World Health Organization estimates that air pollution causes around seven million deaths worldwide each year, mainly from stroke, heart disease, chronic obstructive pulmonary disease, lung cancer and acute respiratory infections.