The AQLI’s 2023 data reveals that global PM₂.₅ concentrations in 2023 were 1.5 percent higher than in 2022 and nearly 5 times the World Health Organization (WHO) guideline of 5 µg/m³. If global particulate pollution were permanently reduced to meet this guideline, an average person around the world would gain 1.9 years of life, adding 15.1 billion total life years to the global population.

Particulate pollution remained the greatest external threat to human life expectancy in 2023, with its impact comparable to smoking and surpassing other major health risks. Its toll on life expectancy is more than 4 times that of alcohol use, 5 times that of transport injuries or unsafe water, sanitation, and handwashing, and more than 6 times that of HIV/AIDS.

United States and Canada. These countries experienced the highest increase in pollution globally. Record-breaking wildfires in Canada fueled the country’s worst air quality since our data records began in 1998 and pushed pollution levels in the United States to their highest since 2011.¹ Wisconsin, Illinois, Ohio, Pennsylvania, Oklahoma, and Mississippi were most affected. Counties in these states replaced California counties as the top 20 most polluted for the first time since 2019. In Canada, more than 50 percent of Canadians breathed air that exceeded their national standard of 8.8 µg/m³ —up from less than 5 percent over the previous five years.²

Latin America. Particulate concentrations in Latin America reached the region’s highest level since our data record began in 1998. Bolivia, the most polluted country in the region, ranked among the top ten most polluted countries in the world for the first time since 2010. The health threat posed by particulate pollution in many parts of Latin America is greater than that of self-harm and violence — nine times greater in Bolivia.

South Asia. After a dip in 2022 compared to 2021, particulate pollution in South Asia increased by 2.8 percent in 2023— though it remained 7 percent lower than in 2021. Despite these fluctuations, South Asia remains the most polluted region in the world. In the region’s most polluted countries, particulate pollution’s impact on life expectancy is nearly twice that of childhood and maternal malnutrition and more than five times that of unsafe water, sanitation and handwashing.

China. After a decade of consistent decline following the start of its “War on Pollution” in 2014, China saw a slight increase of 2.8 percent in particulate pollution in 2023 relative to 2022. Though Chinese citizens are breathing air that is 40.8 percent cleaner than at its worst levels in 2014, they would live 2.2 years longer if China’s particulate pollution levels met the WHO guideline.

Africa. While pollution declined slightly in Central and West Africa, residents in the most polluted parts of the region are losing up to 5 years of life expectancy due to particulate pollution that exceeds the WHO guideline. In these highly-polluted regions—such as Cameroon and the Democratic Republic of the Congo—air pollution takes a greater toll on life expectancy than well-known killers like HIV/AIDS, malaria and unsafe water.

Availability of air quality information has improved worldwide, but 5.5 billion people still lack access to information that can meaningfully aid public or policy action. The share of global population living in countries with government-monitored air quality data has increased from less than 20 percent in 2011 to 85 percent in 2024.⁷ ⁸ However, 68 percent of the world’s population lives in countries where the monitoring density remains below three monitors per million people — the minimum recommended by environmental protection agencies in the U.S. and Europe, leaving nearly 5 billion people without access to adequate information on the quality of the air they breathe.⁹ ¹⁰

Why is air pollution monitoring important? Air pollution concentrations are not a law of nature—they reflect societal choices that are based on the trade-offs between economic growth and the benefits of clean air, regulatory capacity, values, politics and other factors. Without basic air pollution monitoring, there is little reason to believe that society’s goals are being met or that people can protect themselves appropriately.

What has the introduction of air pollution information accomplished in the past? In some important instances, including the United States and China, the availability of reliable data on pollution has been linked to policy changes and improvements in air quality.¹¹ The availability of air pollution data has additionally allowed people to make better decisions about protecting themselves through purchases of air purifiers, masks, and other changes in behavior.¹²

EPIC Air Quality Fund . Last year, EPIC launched the EPIC Air Quality Fund to support local groups and organizations in installing air quality monitors, sharing open data to some of the world’s most polluted communities, and using that data to further national-level impact plans. The fund now supports 31 awardees in government, academia, and civil society who are installing more than 700 monitors across 19 countries.

Initial Impacts. While still early, there are initial indications that these efforts are driving progress at the national level— for example, supporting the creation of the only air quality monitoring network in the Democratic Republic of Congo, and contributing to The Gambia’s environmental protection legislation.