Bangladesh has been named the world's most polluted country while Dhaka has emerged as the second most polluted city in the World Air Quality Report 2020.
The country has ranked top of the worst polluted countries since 2018 and this result showed that the situation did not improve in recent years, said experts. Researchers from IQAir -- a global air quality information and Swiss-based tech company -- analyzed pollution data from 106 countries, specifically measuring PM2.5, a microscopic pollutant that can cause serious health risks.
The report published on Wednesday said the average annual PM2.5 concentrations in Bangladesh was 77.1 micrograms per cubic metre (mcg/m3) of air, which is seven times above WHO exposure recommendation.
Despite various government policies to address the issue, Dhaka's air quality has fallen from where it was three years ago.
Being among the world's megacities of 10 million people or more, the annual average PM2.5 concentrations in Dhaka's air in 2020 was 77.1 micrograms per cubic metre, ranking it the second most polluted capital city in the world.
Meanwhile, Delhi with an average annual PM2.5 concentrations of 84.1 micrograms per cubic metre topped the list.
"South Asia remained the most polluted region of the world with Bangladesh, India, and Pakistan sharing 42 of the 50 most polluted cities worldwide," said the report.
"An estimated 13-22% of deaths in this region are linked to the health effects of air pollution exposure, with associated estimated costs equating to 7.4 of the region's GDP," it added.
84% countries observed improvements to air quality
The report revealed that 84% of all monitored countries observed improvements to air quality, most of which can be explained by measures introduced to slow the spread of Covid-19.
However, of these countries, only 24 out of 106 met the WHO guidelines for PM 2.5 pollution.
In Europe, around half of all cities exceeded the WHO target, with the highest levels seen in Bosnia Herzegovina, North Macedonia and Bulgaria.
In the US, average PM2.5 pollution levels actually rose by 6.7% in 2020.
According to the report, record-breaking wildfires in California, Oregon and Washington were largely to blame and meant that in 2020, at least 38% of American cities did not meet the WHO’s guideline for annual PM2.5 levels, this compares to 21% in 2019.
All Indian cities that were monitored observed air quality improvements. However, India continues to take the lead when it comes to air pollution, with 22 of the top 30 most polluted cities globally located in India.
Frank Hammes, CEO of IQAir, said: "The year 2020 brought an unexpected dip in air pollution. In 2021, we will likely see an increase in air pollution due to human activity, again.
“We hope this report will highlight that urgent action is both possible and necessary to combat air pollution, which remains the world’s greatest environmental health threat.”
Lauri Myllyvirta, lead analyst at the Centre for Research on Energy and Clean Air (CREA), who also contributed to the report, said: “Many parts of the world experienced unprecedented, but short-lived, improvements in air quality in 2020, as restrictions related to the Covid-19 pandemic caused a steep drop in fossil fuel consumption.
“This improved air quality meant tens of thousands of avoided deaths from air pollution. By transitioning to clean energy and clean transport we can realize the same improvements in a sustained way.”
