air quality in Dhaka
Air quality remains ‘unhealthy’ in Dhaka
Dhaka's air quality continues to be 'unhealthy', but the densely populated capital of Bangladesh is no longer the world's most polluted city.
With an air quality index (AQI) of 177 (recorded at 10.23 am), the capital has slipped to the fourth position in the latest list of world cities with the worst air quality.
Kazakhstan’s Nur-Sultan, Pakistan’s Lahore and Poland’s Krakow occupied the first three spots, with AQI scores of 241, 197 and 182, 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 residents.
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.
Read: Dhaka once again ranks world’s most polluted city
Dhaka has long been grappling with air pollution issues. Its air quality usually turns unhealthy in winter and improves during the monsoon.
A report by the Department of Environment (DoE) and the World Bank in March 2019 pointed out that the three main sources of air pollution in Dhaka "are brick kilns, fumes from vehicles and dust from construction sites".
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.
Read: Citing abstention at UNGA vote on Ukraine, Lithuania withdraws vaccine donation to Dhaka
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 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.
Rains lift Dhaka's air quality
The air quality in Dhaka has improved further due to rains for the last few days.
The megacity ranked the 15th worst polluted city in the world in the Air Quality Index (AQI) with an AQI score at 8:08am on Monday.
The air in Dhaka was categorised as ‘moderate’.
AQI: Dhaka’s air quality ‘satisfactory’
The air quality in Dhaka showed a significant improvement on Friday morning with the capital city ranking the 64th worst in the Air Quality Index (AQI).
It had an AQI score of 35 at 09:07am and its air quality was classified as ‘satisfactory’.
When the AQI value is between 0 and 50, the air quality is satisfactory, and air pollution poses little or no risk.