Summary of the Best and Worst Air Quality Places in 2021

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A new report highlighted that air pollution levels soared to unhealthy degrees worldwide in 2021.

According to the IQAir report, which monitors global air quality, on average, air pollution in every country, and 97% of cities, exceeded the air quality guidelines set by the World Health Organization to aid governments in formulating regulations to safeguard public health.

Out of the 6,475 cities analyzed, only 222 cities met the WHO air quality standard. Territories that adhered to WHO guidelines included the French territory of New Caledonia and the United States territories of Puerto Rico and the US Virgin Islands.

Countries such as India, Pakistan, and Bangladesh exhibited some of the worst air pollution, surpassing the guidelines by over 10 times.

Conversely, Scandinavian countries, Australia, Canada, Japan, and the United Kingdom were among the top countries for air quality, reporting levels that exceeded the guidelines by 1 to 2 times.

In the United States, air pollution in 2021 exceeded WHO guidelines by 2 to 3 times.

The CEO of IQAir North America, Glory Dolphin Hammes, emphasized the importance of governments worldwide taking action to reduce global air pollution. She stressed the need for stricter air quality standards and better foreign policies to enhance air quality.


The report by IQAir evaluated average annual air quality for over 6,000 cities, categorizing them based on air quality from the best (“Meets WHO PM2.5 guideline”) in blue to the worst (“Exceeds WHO PM2.5 guideline by over 10 times”) in purple. An interactive map is accessible from IQAir.

This report is notable for being the first major global air quality report based on the World Health Organization’s new annual air pollution guidelines, which were revised in September 2021. The updated guidelines decreased the acceptable concentration of fine particulate matter, PM 2.5, from 10 to 5 micrograms per cubic meter.

PM 2.5 is a minuscule yet hazardous pollutant that can penetrate deep into the lungs and bloodstream when inhaled. It originates from sources like the combustion of fossil fuels, dust storms, and wildfires, and has been associated with various health risks including asthma, heart disease, and other respiratory ailments.

According to the World Health Organization, millions of individuals die annually due to air quality-related concerns, with about 4.2 million premature deaths linked to fine particulate matter in 2016. If the 2021 guidelines had been implemented that year, WHO estimates that almost 3.3 million pollution-related deaths could have been prevented.

IQAir conducted an analysis on pollution-monitoring stations in numerous cities worldwide.

In the United States, air pollution levels rose in 2021 compared to 2020. Los Angeles had the highest pollution levels despite a 6% decrease from the previous year. Conversely, Atlanta and Minneapolis experienced significant increases in pollution.

The authors of the report attributed the rising air pollution in the US to the country’s reliance on fossil fuels, worsening wildfires, and inconsistent enforcement of the Clean Air Act. Fossil fuel-powered transportation, energy production, and wildfires were identified as the primary sources of pollution affecting vulnerable communities.

Climate change-induced wildfires, such as the Caldor and Dixie fires in California and the Bootleg Fire in Oregon, significantly contributed to the decline in air quality in the US in 2021.

On the other hand, China saw an improvement in air quality in 2021, with Beijing maintaining a positive trend due to policies targeting polluting industries.

The report highlighted concerning developments in the Amazon Rainforest, which emitted more carbon dioxide than it absorbed. Deforestation and wildfires in the region have jeopardized the ecosystem, polluted the air, and exacerbated climate change.

Inequality in air quality monitoring was a notable issue, especially in developing regions like Africa, South America, and the Middle East, where data availability remains limited.

The report underscored the importance of transitioning away from fossil fuels to combat global warming and improve air quality. It emphasized the need for decisive action to mitigate the irreversible consequences of climate change.

It was noted that inclusive monitoring networks are crucial to avoiding blind spots in reports on air quality. Despite improvements in monitoring networks, regions with inadequate stations may require alternative techniques for data collection.

The United Nations Intergovernmental Panel on Climate Change emphasized the benefits of reducing fossil fuel usage in slowing global warming, improving air quality, and public health.

The IQAir report serves as a compelling reminder of the urgency to shift towards renewable energy sources and take substantial measures to address global warming.

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