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Wildfires Impact Health Across Every Region in U.S. According to “Health of the Air” Report

Meeting ATS-Recommended Air Quality Standards

Would Save Thousands of Lives

NEW YORK, NY (Nov. 1, 2023) –The American Thoracic Society today published a paper in the Annals of the American Thoracic Society that provides local and national estimates of the health impacts of outdoor air pollution for levels greater than recommended by health experts. The "Health of the Air" report is led by the Marron Institute of Urban Management at New York University and includes contributions from health researchers from multiple U.S. research institutions. To download health impacts by city and state, including lists of the top 25 cities with the highest health impacts from air pollution, see

"Understanding the magnitude of health impacts attributable to outdoor air pollution is often a missing part of the policymaking process. This report provides invaluable information that can help inform difficult air quality management decisions at both the local and national level," said Kevin Cromar, PhD, program director at the Marron Institute of Urban Management at New York University.

National estimates for the health impacts of air pollution levels greater than recommended by the American Thoracic Society include:

  • 21,300 avoidable deaths (95 percent CI: 16,180–26,200);
  • 3,000 new cases of lung cancer (95 percent CI: 1,550–4,390);
  • 10,660 preterm births and/or low birth weight; (95 percent CI: 3,180–18,330);
  • 748,660 occurrences of various cardiovascular and respiratory morbidities (95 percent CI: 326,050–1,057,080); and,
  • 4 million adversely impacted days (95 percent CI: 7.9–92.4 million).

The health estimates in this study reflect how many additional negative health outcomes could be avoided if ATS-recommended air quality standards been met in all counties with an air pollution monitor. These estimates are calculated using a similar approach to what the EPA uses for regulatory assessments to allow for direct comparisons with other policy relevant health impact assessments.


But not all air pollution can be readily addressed through revisions to national air quality standards. This report provides the first-ever local and national estimates of the health impacts specifically attributable to air pollution from wildland fires. Funding from NASA, through the Health and Air Quality Applied Science Team (HAQAST), allowed for the inclusion of this critical source of pollution into the health analysis.

The annual mortality impacts in the U.S. attributable to air pollution from wildland fires is a low estimate of 4,080 additional deaths each year (95 percent CI: 240–7,890); and a middle estimate of 28,000 additional deaths each year (95 percent CI: 27,300–28,700). The difference in the low and middle estimates is based on uncertainty regarding the mortality risks of smoke from wildland fires and how it specifically differs from pollution from other combustion sources.

The health impacts from wildland fires are not only a problem in the western and southern parts of the United States, where most of the wildland fires impacts are expected, but are shown to occur in every region of the country. "Although the megafires are more newsworthy, air quality and health burdens from wildland fires are also driven by the cumulative impacts from the many smaller fires that are burning on any given day across North America," said Daniel Tong, PhD, associate professor at George Mason University and a member of NASA HAQAST.


Adverse health burdens due to outdoor air pollution occur across the entire age spectrum, and for the first time, this year's report provides estimates of the number of excess adverse birth outcomes attributable to elevated air pollution. Funding from the Environmental Defense Fund (EDF) supported the efforts to include this important health category in this analysis.

"The U.S. EPA has yet to incorporate adverse birth outcomes as part of their regulatory process, but there is now sufficient scientific evidence linking elevated air pollution with increased risk of preterm birth and low birth weight to merit its inclusion in future regulatory impact assessments and other policy relevant analyses.," said Julia Gohlke, PhD, MS, lead senior scientist, health at Environmental Defense Fund.


The standards for PM2.5 and ozone are currently under review by the U.S. EPA but the EPA Administrator has proposed setting less stringent standards than those recommended by the American Thoracic Society. The ATS report reaffirms its recommendations to: (1) limit long-term (annual) PM2.5 exposure to 8 micrograms per cubic meter (8 µg/m3) and to (2) limit short-term (daily) exposure to 25 µg/m3. The ATS report also reaffirms its recommendation of limiting ozone to 60 parts per billion (ppb).

“If implemented, these changes would save thousands of lives,” said Gary Ewart, MHS, chief, Advocacy & Government Relations at American Thoracic Society. “Existing EPA pollution standards have been shown to still allow significant morbidity and mortality. While the EPA is considering revision of their particulate standards, we continue to advise them to review the evidence in this unique report and consider more health protective recommendations.”