Bangladesh and Chad were world's most polluted countries in 2024
What's the story
Only seven countries met the World Health Organization's (WHO) air quality standards in 2024. They were Australia, New Zealand, the Bahamas, Barbados, Grenada, Estonia, and Iceland.
Meanwhile, Chad and Bangladesh were the world's most polluted countries last year, with average smog levels over 15 times higher than WHO guidelines.
The figures were compiled by Swiss air quality monitoring firm IQAir.
Problems
Gaps in data from Asia and Africa
There are significant data gaps in Asia and Africa, as many developing nations have relied on air quality sensors mounted on US embassy and consulate buildings to track smog levels.
The US State Department recently ended this scheme, citing budget constraints.
This has raised concerns among researchers about the future of global air quality monitoring efforts.
Data concerns
Impact on Africa's air quality monitoring
Christi Chester-Schroeder, IQAir's air quality science manager, said, "Most countries have a few other data sources, but it's going to impact Africa significantly because these sensors often provide the only publicly available real-time air quality monitoring data."
Chad was barred from IQAir's 2023 list due to data concerns, but was also ranked as the most polluted nation in 2022, plagued by Sahara dust and uncontrolled crop burning.
Pollution levels
India's air quality
In India, average PM2.5 levels fell by 7% to 50.6 mg/cu m last year, placing it fifth in the smog rankings behind Chad, Bangladesh, Pakistan, and the Democratic Republic of Congo.
Byrnihat in Meghalaya clocked an average PM2.5 level of 128 mg/cu m.
Climate change increasingly contributes to pollution as rising temperatures lead to more intense and longer forest fires across Southeast Asia and South America.
Data loss
Effect of closure of US monitoring program
Christa Hasenkopf, the Director of the Clean Air Program at the University of Chicago's Energy Policy Institute (EPIC), warned that at least 34 nations will lose access to reliable pollution data with the US program's closure.
Reportedly, the initiative had improved air quality in cities where monitors were installed, boosted life expectancy, and reduced hazard allowances for US diplomats.
Hasenkopf described its termination as "a giant blow to air quality efforts worldwide."