
2024
World Air Quality Report
0-5
Meets WHO guideline
5.1-10
Exceeds by 1 to 2 times
10.1-15
Exceeds by 2 to 3 times
15.1-25
Exceeds by 3 to 5 times
25.1-35
Exceeds by 5 to 7 times
35.1-50
Exceeds by 7 to 10 times
>50.1
Exceeds by over 10 times
The 2024 World Air Quality Report evaluates the global state of air quality for the year 2024. This comprehensive report presents PM2.5 air quality data collected from 8,954 cities across 138 countries, regions, and territories. The data used herein is sourced from over 40,000 regulatory air quality monitoring stations and low-cost sensors, operated by a diverse range of entities, including government agencies, research institutions, non-profit organizations, schools, universities, private sector companies, and dedicated citizen scientists worldwide.
The PM2.5 data is measured in micrograms per cubic meter (μg/m³) and the data is visualized as a function of the World Health Organization (WHO) annual PM2.5 air quality guideline. The air quality metrics included in this 2024 report derive from IQAir’s real-time online monitoring platform, which systematically validates, calibrates, and harmonizes data from air quality monitoring stations globally.
For further historic air quality information categorized by city, country, and region, the IQAir website offers an interactive map displaying annual city concentrations alongside global rankings of air quality for the 8,954 cities featured in this report. IQAir is committed to engaging, informing, and inspiring a collaborative effort among governments, educators, researchers, non-profit organizations, businesses, and citizens to elevate air quality awareness. Our goal is to facilitate informed dialogue and promote actions that enhance air quality and safeguard the health of communities and cities around the world.
Air pollution remains the greatest environmental threat to human health. According to the World Health Organization (WHO), 99% of the global population lives in areas that do not meet recommended air quality guideline levels.1 Air pollution is the second leading global risk factor for death, and the second leading risk factor for deaths among children under five, following malnutrition, due to its significant impact on respiratory and developmental health.2 In 2021 alone, 8.1 million total deaths were attributable to air pollution, with 58% of those deaths caused by ambient PM2.5 air pollution.3
The United Nations has declared access to healthy air is a universal human right.4 Exposure to PM2.5 contributes to and exacerbates various health conditions, including asthma, cancer, stroke, and lung diseases.5 In addition, exposure to elevated levels of fine particles during pregnancy and early childhood are associated with congenital heart defects, eczema and allergic disease, cognitive impairments and delays, neurodevelopmental disorders, and mental health disorders.6
The data used to create this report was compiled from over 40,000 air quality monitoring stations and low-cost sensors worldwide, operated by research institutions, government agencies, schools, universities, non-profit organizations, private companies, and citizen scientists.
The 2023 World Air Quality Report included data from 7,812 locations in 134 countries, regions, and territories. In 2024, those numbers have grown to 8,954 cities in 138 countries, regions, and territories. Coverage has expanded in Africa to include Chad, the most polluted country in 2024, along with Djibouti and Mozambique. The countries of Iran, Afghanistan, and Burkina Faso (ranked 5th most polluted country in 2023) are notably absent in 2024 due to a lack of data availability.
Only 12 countries, regions, and territories recorded PM2.5 concentrations below the WHO annual PM2.5 guideline of 5.0 μg/m³, most of which were in the Latin America and Caribbean or Oceania region; however in 2024, 17% of cities included in the report met the WHO annual PM2.5 guideline level, up from 9% in 2023. While this marks some progress, much more work has yet to be done to protect human health, especially that of children. It is our shared responsibility to safeguard the health and well-being of the world’s children, who will one day become the leaders of tomorrow. By equipping them with the knowledge and resources they need, we empower them to tackle the global challenges of the future.
[1] World Health Organization. (October 24, 2024). https://www.who.int/news-room/fact-sheets/detail/ambient-(outdoor)-air-quality-and-health
[2] Health Effects Institute. 2024. State of Global Air 2024. Special Report. Boston, MA. https://www.stateofglobalair.org/resources/report/state-global-air-report-2024
[3] Health Effects Institute. 2024. State of Global Air 2024. Special Report. Boston, MA. https://www.stateofglobalair.org/resources/report/state-global-air-report-2024
[4] United Nations. UN General Assembly declares access to clean and healthy environment a universal human right. Published July 28, 2022. https://news.un.org/en/story/2022/07/1123482
[5] U.S. Environmental Protection Agency. Health and environmental effects of particulate matter (PM). Published July 16, 2024. https://www.epa.gov/pm-pollution/health-and-environmental-effects-particulate-matter-pm
[6] Boston College, MassCleanAir. Children’s health. https://www.bc.edu/bc-web/centers/schiller-institute/sites/masscleanair/articles/children.html