The densely populated capital of Bangladesh continues to dominate the list of world cities with the worst air quality.
On Friday, Dhaka occupied the first position in the list. The city of Beijing in China occupied the second place. The third and fourth spots were grabbed by Kathmandu of Nepal and Delhi of India, respectively.
Dhaka's air quality index (AQI) was recorded at 237 around 2 am, which is considered 'very unhealthy’'
An AQI between 201 and 300 is considered "poor," while a reading of 301 to 400 is said to be "hazardous," posing serious health risks to city residents.
According to the World Health Organization (WHO), air pollution kills an estimated seven million people worldwide every year
In Bangladesh, the overall 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 characterized
by wide seasonal variations in rainfall, high temperatures and humidity.
Generally, Dhaka’s air starts getting fresh when monsoon rains begin in
mid-June. The air remains mostly acceptable from June to October.
In February last year, Bangladesh's Environment, Forests and
Climate Change Minister Md Shahab Uddin admitted that air pollution levels in
the capital "has reached an extreme level."
"This is mainly due to uncontrolled discharge of dust
from construction projects, smoke from vehicles and brick kilns," he told
UNB.
"Brick kilns are responsible for 58% of air pollution in the capital. There are plans to shut down (traditional) kilns in operation. We plan to stop burning bricks at all kilns by 2025 and use block bricks to construct buildings under government projects," he said then.
Besides, on January 31, the High Court directed the
authorities concerned to shut down all illegal brick kilns by February 18.
Air pollution consistently ranks among the top risk factors
for death and disability worldwide. Breathing polluted air has long been
recognized 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.
Over 80 percent living in urban areas, which monitor air
pollution, are exposed to air quality levels that exceed WHO guideline limits,
with low- and middle-income countries most at risk.