Dhaka city has been witnessing a marked improvement in air quality for a couple of days due to seasonal showers as well as fewer people on the roads in the city after Eid-ul-Azha festival.
The air quality in the city witnessed a marked improvement in the morning on Friday (July 22). The air quality of previous days of this week also showed better than other days of the year.
With an air quality index (AQI) score of 65, recorded at 10.40am on Friday, the capital city ranked 22th in the list of world cities with the worst air quality.
An AQI between 50 and 100 is considered ‘moderate’ with an acceptable air quality. However, there may be a moderate health concern for a very small number of people who are unusually sensitive to air pollution.
Kuwait city, Jakarta of Indonesia, and Delhi of India occupied the first three spots in the list with AQI scores of 166, 161 and 154 respectively.
An AQI between 101 and 200 is considered ‘unhealthy’, particularly for sensitive groups.
Similarly, an AQI between 201 and 300 is said to be ‘poor’, while a reading of 301 to 400 is considered ‘hazardous’, posing serious health risks to people.
AQI, an index for reporting daily air quality, is used by government agencies to inform 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.
Dhaka faces pollution problems from all sides, as being a highly populated city. Alongside other pollutions, the capital city of Bangladesh has long been grappling with air pollution issues. The air quality of the city and its surrounding cities usually turns unhealthy during winter and improves during monsoon.
A report by the Department of Environment and the World Bank in 2019 pointed out that the three main sources of air pollution in Dhaka and its surrounding areas. The reasons are brick kilns, fumes from vehicles and dust from construction sites.
With the advent of winter, the air quality of Dhaka city starts deteriorating sharply due to the massive discharge of pollutant particles from construction works, 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 heart disease, chronic respiratory diseases, lung infections and cancer, according to several studies.
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.
Besides the air pollution, Dhaka has also long been facing dust pollution and also the sound pollution.
