According to data released by IQAir - a Swiss-based air quality monitoring company - on March 11, only seven countries worldwide met WHO's air quality standards in 2024. These countries are Australia, New Zealand, Bahamas, Barbados, Grenada, Estonia, and Iceland.
Meanwhile, air pollution remains a significant problem in many parts of the world.
Chad, a poverty-stricken country in Central Africa, was recorded as the most polluted nation in 2024, with particulate matter (PM2.5) levels averaging 15 times higher than WHO's recommended limit.
Specifically, Chad's average PM2.5 level reached 91.8 micrograms per cubic meter, while WHO's safe threshold is 5 micrograms per cubic meter.
Besides Chad, the four other countries with the most severe pollution were Bangladesh, Pakistan, the Democratic Republic of the Congo, and India.
India, the most populous country, ranks fifth in the list of most polluted countries but has 12 locations among the 20 most polluted cities globally.
Notably, Byrnihat, a city in northeastern India, recorded an average PM2.5 level of 128 micrograms per cubic meter, 25 times higher than WHO's recommendation.
The global air quality picture is obscured by significant data gaps, particularly in Asia and Africa. Many developing countries rely on air quality sensors mounted on US embassies and consulate buildings to track pollution levels.
However, the US Department of State recently ended this scheme due to budget constraints, with more than 17 years-worth of data removed last week from the US government's official air quality monitoring site.
This decision raises concerns as at least 34 countries may lose access to reliable pollution data after the US programme was closed.
Christa Hasenkopf, director of the Clean Air Programme at the University of Chicago's Energy Policy Institute (EPIC), believes that the State Department scheme improved air quality in the cities where the monitors were placed, boosting life expectancy and even reducing hazard allowances for US diplomats.
Ending the scheme will create a significant gap in global efforts to control air pollution. Experts warn that climate change is contributing to increased air pollution worldwide. Higher temperatures lead to more severe and prolonged wildfires, especially in Southeast Asia and South America. These wildfires significantly increase PM2.5 levels, severely impacting human health.
Shweta Narayan, an expert at the Global Climate and Health Alliance, notes that the areas with the most severe pollution are also those with high greenhouse gas emissions from burning coal, oil, and gas. She emphasises that air pollution and the climate crisis are two sides of the same coin.
Despite the severity of air pollution, some cities have successfully improved air quality by implementing strict controls. Beijing (China), Seoul (Republic of Korea), and Rybnik (Poland) have significantly reduced pollution levels through policies limiting emissions from vehicles, power plants, and industries. These cities have also promoted the use of clean energy and invested in public transportation.
ASEAN has signed the Agreement on Transboundary Haze Pollution (AATHP) to prevent and mitigate the transboundary haze pollution caused by land and forest fires, a significant issue in the region during the dry season.
Although the agreement's effectiveness is limited, it marks an important step in regional cooperation to reduce air pollution.
According to WHO, air pollution is the largest environmental threat to human health, causing approximately seven million deaths annually worldwide. This underscores the urgent need to enhance measures to control and reduce air pollution to protect public health and the global ecosystem.
