Wildfire Smoke Exposure Heightens Lung Cancer Risks and Complicates Patient Outcomes

As wildfires intensify due to climate change, the health risks associated with inhaling wildfire smoke are becoming increasingly alarming, particularly in regions like Los Angeles, where air quality has drastically declined due to ongoing fires. Emerging research brings attention to the connection between wildfire smoke exposure and lung cancer, underscoring the importance of increased public awareness and proactive measures.^1,2

Man holding protective mask with wildfire in background | Image Credit: © kashiStock - stock.adobe.com

Lung cancer is one of the leading causes of cancer-related deaths worldwide, and some studies suggest that exposure to wildfire smoke may contribute to these rates. According to the US Department of Agriculture’s Forest Service (USFS), wildfire smoke contains fine particulate matter (PM2.5), a dangerous pollutant capable of penetrating deep into the lungs, which can trigger inflammation, cellular damage, and long-term health consequences. Researchers have linked prolonged exposure to PM2.5 with an elevated risk of developing lung cancer and other chronic conditions.¹

Wildfire smoke carries a mixture of toxic compounds released from natural and manmade burning materials that can exacerbate respiratory and cardiovascular conditions, as well as contribute to cancer development. Firefighters battling wildfires face some of the greatest risks. A study published by the USFS found that firefighters with exposure to wildland smoke have a 43% increased risk of lung cancer mortality and 30% increased risk of cardiovascular disease mortality.^1,3,4

Patients recovering from lung cancer surgery are also at greater risk of adverse health outcomes. In a cohort study of over 460,000 patients, researchers reported that exposure to wildfire smoke during recovery significantly reduces overall survival (OS) rates in patients who underwent curative-intent non–small cell lung cancer resection. According to the data, individuals exposed to a wildfire within 3 months, between 4 and 6 months, and between 7 and 12 months after discharge from the hospital all had worse outcomes.⁵

In another study published in January 2025, patients undergoing radiation treatment for lung cancer who were exposed to wildfire smoke also had worse OS rates compared with those who were not exposed.³

In addition to lung cancer risk, wildfires are often associated with increased emergency room visits for asthma, chronic obstructive pulmonary disease, and cardiovascular conditions. Vulnerable populations, including children, older adults, pregnant individuals, and those with preexisting health conditions, are at even greater risk. Wildfire smoke exposure has been linked to lower birth weights, preterm births, and long-term developmental issues in children. Older individuals may experience worsened cardiovascular or respiratory health.²

As wildfires become more frequent and intense, reducing smoke exposure is critical to mitigating its health impacts. Staying indoors with the windows and doors closed can help maintain cleaner air, especially when paired with the use of air purifiers. Limiting physical activity during periods of poor air quality and seeking shelter in clean air spaces can also minimize harm. When outdoors, wearing an N95 mask provides effective protection against inhaling harmful particles. Respirators are also helpful because they can cover the nose and mouth to filter out smoke and ash particles.^2-4

Proactive measures are essential to reduce long-term health consequences of wildfire smoke exposure. Collaborative efforts between health care professionals, policymakers, and communities can improve preparedness and response strategies, ensuring that individuals affected by wildfires receive the support and resources they need. Pharmacists are uniquely positioned to assist in these efforts by providing individuals with education about the dangers of lung inhalation, as well as necessary medical treatments to alleviate symptoms.³

REFERENCES

1. Navarro KM, Kleinman MT, Mackay CE, et al. Wildland firefighter smoke exposure and risk of lung cancer and cardiovascular disease mortality. Environ Res. 2019. doi:10.1016/j.envres.2019.03.060

2. Borunda A. LA wildfires bring another health hazard: smoke. NPR. January 8, 2025. Accessed January 13, 2025. https://www.npr.org/2025/01/08/nx-s1-5252485/la-fire-air-quality

3. Gallagher A. As wildfires spread across California, pharmacists' role in the crisis proves essential. Pharmacy Times. January 10, 2025. Accessed January 13, 2025. https://www.pharmacytimes.com/view/as-wildfires-grow-across-california-pharmacists-role-in-the-crisis-proves-essential

4. Wittenberg A. Cancer is the unseen danger in the Los Angeles fires. E&E News. January 13, 2025. Accessed January 13, 2025. https://www.eenews.net/articles/cancer-is-the-unseen-danger-in-the-los-angeles-fires/

5. Zhang D, Xi Y, Boffa Y, et al. Association of wildfire exposure while recovering from lung cancer surgery with overall survival. JAMA Oncol. July 27, 2023. doi:10.1001/jamaoncol.2023.2144