Dhaka:Dhaka was ranked fourth among the world's most polluted cities on Friday morning, recording an Air Quality Index (AQI) score of 160 at 930 am.
According to United News of Bangladesh, the city's air quality was classified as 'unhealthy', implying that pollution levels could pose health risks to the general population. India's Delhi topped the list with an AQI score of 334, followed by Manila in the Philippines with 171. Kolkata, also in India, ranked third with a score of 169.
The AQI scale defines a reading of 101 to 150 as 'unhealthy for sensitive groups', while 151 to 200 is classified as 'unhealthy'. A reading between 201 and 300 is considered 'very unhealthy', and scores above 301 are classified as 'hazardous', posing serious health risks.
The AQI provides daily updates on air quality, offering insights into how clean or polluted the air is and indicating potential health risks. In Bangladesh, the AQI is calculated based on five major pollutants particulate matter (PM10 and PM2.5), nitrogen dioxide (NO2), carbon monoxide (CO), sulphur dioxide (SO2), and ozone.
Dhaka has long struggled with air pollution, with air quality generally deteriorating during winter and improving during the monsoon season. The World Health Organization estimates that air pollution causes around seven million deaths worldwide each year, primarily from stroke, heart disease, chronic obstructive pulmonary disease, lung cancer, and acute respiratory infections.