MONDAY, Sept. 21, 2026 (HealthDay News) — Wildfire smoke might pose a greater health risk to humans than other sources of air pollution, two new Mount Sinai studies say.
Particle pollution from wildfires appears to diminish the survival odds of lung cancer patients, a study published Sept. 15 in The Lancet Oncology found.
Wildfire smoke is also linked to an increased risk of hospitalization for heart or lung disease, researchers reported Sept. 17 in the journal Nature Communications.
“Wildfire smoke is no longer a regional environmental issue. It is becoming a nationwide public health challenge,” said Yaguang Wei, senior author of both studies. He is an assistant professor of environmental medicine at Icahn School of Medicine at Mount Sinai in New York City.
“Our research shows that wildfire-related (particle pollution) appears to be more harmful than equivalent levels of pollution from other sources,” Wei said in a news release. “As wildfire activity increases, public health and environmental policies must account for both the quantity and the source of air pollution.”
For both studies, Wei’s teams focused on fine particulate matter found in wildfire smoke. This matter is called PM2.5 because it consists of airborne particles 2.5 microns or smaller in diameter — by comparison, a human hair is 50 to 70 microns wide.
For the first study, researchers analyzed data from more than 414,000 seniors 65 and older with lung cancer.
The team assessed patients’ exposure to particle pollution based on where they lived and tested exposure to pollution from wildfire smoke compared to other sources like cars or power plants.
Results showed that while any exposure to particle pollution increased a lung cancer patient’s risk of death, wildfire smoke was particularly toxic to them. The more smoky days and the longer the smoke exposure, the poorer the survival rates.
Overall, wildfire smoke accounted for only 4% of all the particle pollution the patients faced, but was responsible for about 17% of early death related to air pollution exposure.
“Patients with lung cancer are already medically vulnerable, and our findings suggest that wildfire smoke may place them at even greater risk,” lead researcher Min Zhang, a postdoctoral fellow with the Icahn School of Medicine at Mount Sinai, said in a news release.
Co-author Christine Ekenga, an assistant professor at Emory University in Atlanta, noted that lung cancer patients are already navigating substantial health challenges.
“Our findings suggest that long-term exposure to wildfire smoke may add another, potentially preventable risk,” she said in a news release.
“We need to better understand which patients are most vulnerable and develop practical strategies to reduce their exposure," Ekenga added.
In the second study, researchers analyzed records for more than 57 million heart-related hospitalizations and nearly 33 million lung-related hospitalizations across 20 U.S. states between 2006 and 2019.
The team linked those records to air quality data showing nearby particle pollution from wildfires and other sources.
Long-term exposure to wildfire smoke was associated with increased risks for hospitalization across a broad range of conditions, including heart failure, heart disease, high blood pressure, asthma, pneumonia and COPD.
Wildfire particle pollution was consistently linked with higher increases in hospitalization risk than other sources, researchers said.
“We found that wildfire smoke can affect both the lungs and the cardiovascular system, and that its effects may be stronger than those of similar amounts of pollution from traffic, industry and other sources,” Zhang said.
Future work should consider which chemical components of wildfire smoke are responsible for its toxicity, and how the body’s response to this pollution affects heart and lung health, researchers said.
“As wildfire activity continues to grow around the world, understanding the health consequences of wildfire smoke has become increasingly urgent,” Wei said. “These studies represent an important step toward identifying who is most vulnerable and what strategies may help protect public health in a changing climate.”
More information
The U.S. Environmental Protection Agency has more about particle pollution.
SOURCE: Mount Sinai, news release, Sept. 17, 2026
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