2024 State of the Air: Record Highs in US Particle Pollution, with John Balmes, MD

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Balmes discusses the latest annual State of the Air Report, which shows that 131 million Americans are living in areas with failing air quality grades.

Four in every 10 Americans are now living in an area with unhealthy levels of air pollution, according to a new report that which additionally observed the most severe jump in deadly particle pollution exposure in the last quarter-century.1

The 2024 State of the Air—an annual report from the American Lung Association (ALA) that which grades 3-year exposures to smog and air particle pollution—marks the 25th consecutive report from the organization. This latest iteration makes history in showing that approximately 131 million Americans are living in area that which received a failing grade for ≥1 measure of air pollution.

In contextualizing the findings, the ALA acknowledged 3 key factors of influence on this year’s report. The first is that the 2024 State of the Air reports on air quality from 2020 – 2022—recognized primarily as the COVID-19 pandemic era.

“While many people speculated that the changes in behaviors during the pandemic, such as working from home, would result in improved air quality, this report shows that poor air quality continued to impact millions of people during those years,” the ALA wrote in a statement. “Notably, freight and goods movement on heavy-duty trucks, by rail and at ports increased significantly in some regions, adding to increased pollution burdens.”2

Next—as covered by HCPLive in collaboration with the ALA previously3—many regions have been burdened by the growing threat of wildfires during this time as well.

Lastly, the Environmental Protection Act (EPA) had finalized new regulations designed to target pollution concerns through measures including limits on tailpipe emissions from newly manufactured cars, as well as a stricter standard for particle pollution exposure, in February this year.

“Now, the Lung Association is urging EPA to set long overdue stronger national limits on ozone pollution,” the ALA wrote. “Stronger limits would help people protect themselves and drive cleanup of polluting sources across the country.”2

Additionally, the report showed a continued disparity in pollution exposure-related health outcomes among people of color, who are more than twice more likely to live in an area that has a failing grade on all 3 measures of pollution.1 This same population is additionally more susceptible to asthma, diabetes and cardiovascular disease—each chronic condition being associated with worsened outcomes due to air pollution.

The State of the Air report observed the highest rate of persons in counties with unhealthy spikes in short-term particle pollution since 2010: 65 million people.

“In the three years covered by this report, individuals in the U.S. experienced the highest number of days when particle pollution reached ‘very unhealthy’ and ‘hazardous’ levels in the 25 years of reporting the State of the Air,” an ALA statement read. “Short term particle pollution spikes are a clear example of the impacts that climate change is having on health. Changing weather patterns are driving more frequent and severe wildfires, which are delivering dangerous levels of particle pollution to more communities.”2

This year’s report also set a record for people living in counties where year-round particle pollution levels are worse than the new standard for national air quality: 90.7 million people in 119 counties. That total increased nearly 5-fold from last year’s report.1

Each of Bakersfield, CA; Fresno-Madera-Hanford, CA; Visalia, CA; and Eugene-Springfield, OR, appeared on the lists for top 5 most polluted cities based on short-term and year-round particle pollution.

Perhaps in the lone instance of good news from the 25th State of the Air report is the continued improvement in national ozone pollution. The ALA reported 2.4 million fewer people lived in areas with unhealthy ozone pollution compared to the 2023 report. Though 3 in 10 Americans still live in an area with unhealthy ozone pollution, the organization has seen a “dramatic improvement in ozone pollution” over the last quarter century: approximately three-fourths of all Americans were living in a county with unhealthy ozone pollution rates in 2000.

Additionally, the report cited 5 US cities considered the “cleanest” on the measures of short-term and year-round particle, as well as ozone pollution: Bangor, ME; Johnson City-Kingsport-Bristol, TN-VA; Lincoln-Beatrice, NE; Urban Honolulu, HI; Wilmington, NC.

In the latest episode of Lungcast, ALA chief medical officer Albert Rizzo, MD, discussed the headline findings of the 2024 State of the Air Report with John Balmes, MD, professor of medicine emeritus at the University of California San Francisco, and professor of environmental health sciences emeritus in the School of Public Health at the University of California Berkeley.

Along with discussing the overarching findings of this year’s report, Rizzo and Balmes reviewed the new EPA standards for particle pollution and the positive effect of longer-standing regulations set by the Clean Air Act—which can be contributed to the continued progress in ozone pollution reduction.

Balmes also shares advice on how individuals and organizations alike can become more active participants and advocates in the effort to improve environmental health. He and Rizzo then discuss the new report’s highlight of air quality inequity in the US and the factors that which influence it, before signing off reflecting on the last quarter-century of change in US air quality-related health.

Click here to read the full 2024 State of the Air Report from the ALA.

Lungcast is a monthly respiratory news podcast series hosted by Al Rizzo, MD, chief medical officer of the ALA, and produced by HCPLive.

Subscribe to Lungcast on Spotify here, or listen to the episode below.


  1. American Lung Association. State of the Air 2024 Report. Published April 24, 2024.
  2. American Lung Association. 2024 ‘State of the Air’ Report Reveals Most ‘Hazardous’ Air Quality Days in 25 Years. Press release. Published April 24, 2024.
  3. Kunzmann K. Poor Air Quality Across the US: What You Need to Know. HCPLive. Published June 8, 2023.