Shwdesh Desk:

Dhaka ranked as the 18th most polluted city in the world on Monday morning as per Air Quality Index.

The air in Dhaka was categorised as ‘unhealthy for sensitive groups’ in the morning and the megacity had an AQI score of 123 at 9:33am.

Russia’s Krasnoyarsk, Poland’s Krakow and Bosnia Herzegovina’s Sarajevo occupied the first three spots, with AQI scores of 199, 186 and 182, respectively.

When the AQI remains in between 101 and 150, members of sensitive groups may experience health effects. The general public is less likely to be affected in this condition.

In this range, people with heart or lung disease, older adults, children, people with diabetes, and people of lower SES are advised to reduce prolonged or heavy exertion.

An AQI between 151 and 200 is considered ‘unhealthy’ while 201-300 is considered ‘very unhealthy’, and 301-400 is ‘hazardous’, posing severe health risks to residents.

The AQI, an index for reporting daily air quality, informs people how clean or polluted the air of a certain city is, and what associated health effects might be a concern for them.

In Bangladesh, the AQI is based on five criteria pollutants — Particulate Matter (PM10 and PM2.5), NO2, CO, SO2, and Ozone (O3).

Bangladesh has a subtropical monsoon climate characterised by wide seasonal variations in rainfall, high temperatures and humidity.

With the advent of winter, the city’s air quality starts deteriorating sharply due to the massive discharge of pollutant particles from construction work, rundown roads, brick kilns and other sources.

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 Organisation, 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.