Last week, as wildfires swept through Southern California, gray skies and thick, acrid smoke served as a stark reminder of the lasting dangers these disasters leave behind.
And as of the date of this post, the fires are still not under complete control. Beyond the visible destruction of homes and landscapes, the smoke carries a toxic cocktail of particulate matter and harmful chemicals, infiltrating the airways of residents and first responders—and affecting not just those in the immediate areas but also communities downwind.
Among the many health risks, the presence of cancer-causing compounds in the smoke has emerged as a serious concern, with potential consequences that could persist long after the flames have been extinguished. Long after the fires subside and the smoke clears from view, the lasting impact of inhaling these toxic particulates may persist for years.
Wildfire Smoke: A Tale of Two Fires
Wildfires are not all created equal. The composition of smoke varies dramatically depending on what is burning. In forested areas, wildfire smoke primarily consists of organic matter such as burning trees, grasses, and vegetation. While still harmful, the smoke from these fires is largely made up of particulate matter (PM2.5) and volatile organic compounds (VOCs). These particles can irritate the respiratory system and trigger inflammation but are often less toxic than the chemical-laden smoke from urban fires.
In urban settings, wildfires tear through homes, vehicles, and infrastructure, releasing a far more toxic brew into the air. The combustion of synthetic materials, plastics, treated wood, and industrial chemicals produces highly hazardous compounds such as dioxins, furans, heavy metals, and polycyclic aromatic hydrocarbons (PAHs). These substances are not just irritants; many are known carcinogens that can accumulate in the body and increase cancer risk over time.
According to a study published in Ecotoxicology and Environmental Safety, “Even lower levels of exposure to PM2.5 from wildfires were related to elevated mortality risks for cancer from total, lung, LOP, highlighting the importance of wildfire prevention and control.”
The difference in smoke composition is critical to understanding the long-term health impacts. While any wildfire smoke can pose health dangers, urban wildfires expose people to a heightened level of toxic chemicals that make prolonged exposure particularly concerning. For fires that encroach on populated areas, the stakes for public health are alarmingly high.
How These Particles Affect Cancer Risk
The health risks of wildfire smoke go beyond short-term respiratory irritation and extend into the realm of long-term, potentially life-altering consequences. Prolonged or repeated exposure to the toxic particles in smoke can significantly increase cancer risk through several mechanisms:
Lung Cancer: A Direct Assault on Lung Tissue
When fine particulate matter (PM2.5) from wildfire smoke is inhaled, it penetrates deep into the lungs, damaging the delicate tissues responsible for oxygen exchange. Over time, this damage can lead to chronic inflammation and cellular changes, creating an environment conducive to cancer development. Compounding the risk, the chemicals in wildfire smoke, such as polycyclic aromatic hydrocarbons (PAHs), are potent carcinogens known to directly damage DNA and promote tumor growth in the lungs.
Blood Cancers: The Benzene Connection
Benzene, a volatile organic compound released during the combustion of organic and synthetic materials, poses a significant threat to blood health. Benzene is a well-established carcinogen linked to leukemia and other blood cancers. When inhaled, benzene can enter the bloodstream, disrupt the production of healthy blood cells, and damage the bone marrow. Urban wildfires, which burn plastics, fuels, and chemicals, release higher concentrations of benzene, increasing the risk for those exposed.
General Toxicity: The Role of Inflammation and Oxidative Stress
Beyond specific cancer types, the systemic effects of wildfire smoke create a dangerous cascade of health issues. The fine particles and toxic chemicals in the smoke generate oxidative stress, overwhelming the body’s ability to neutralize harmful free radicals. This oxidative stress damages cells and DNA, creating fertile ground for cancer to develop. Simultaneously, the persistent inflammation triggered by these toxins weakens the immune system, reducing the body’s ability to detect and eliminate precancerous cells.
The cumulative impact of these exposures is concerning, especially for individuals living in wildfire-prone areas or first responders who face repeated contact with toxic smoke. Recognizing the mechanisms by which these particles affect cancer risk underscores the urgent need for preventive measures and proactive health monitoring.
Reducing Exposure and Mitigating Risks
While wildfires and the smoke they produce may be beyond your control, there are steps you can take to minimize your exposure and support your body in mitigating the health risks associated with toxic particles. Here’s how:
1. Protect Yourself with Proper Masks. A standard cloth mask or surgical mask won’t filter out the fine particulate matter (PM2.5) and harmful chemicals in wildfire smoke. Use an N95 mask or higher-grade respirator to provide effective protection. These masks are specifically designed to filter out tiny particles and can significantly reduce your exposure while outdoors.
2. Improve Indoor Air Quality. Since smoke can seep into homes, maintaining clean indoor air is essential:
- Invest in HEPA air purifiers, which can trap fine particles and reduce airborne toxins in your living spaces.
- Seal windows and doors with weather stripping or tape to prevent smoke from entering.
- Consider creating a “clean air room” in your home by running a HEPA filter in a single, well-sealed space.
3. Limit Outdoor Activities. When smoke levels are high, stay indoors as much as possible, especially during peak smoke periods. Avoid strenuous outdoor activities, as deep breathing increases the amount of toxins absorbed into the lungs.
4. Support Your Body with Detox-Supportive Foods and Supplements. Help your body combat the oxidative stress and toxin load caused by smoke exposure by incorporating the following into your diet:
- Cruciferous Vegetables: Broccoli, kale, and Brussels sprouts are rich in sulforaphane, which supports detoxification pathways.
- Activated Charcoal: Binds to toxins in the digestive tract, helping to eliminate them from the body.
- Glutathione: Known as the body’s “master antioxidant,” glutathione helps neutralize free radicals and supports liver detoxification.
- Vitamin C and E: These antioxidants can reduce oxidative stress and inflammation.
- Hydration: Drink plenty of water to help flush toxins from your system.
By taking proactive steps—like wearing an N95 mask, investing in clean air technology, and supporting your body with detoxifying foods—you can protect yourself and your loved ones from the long-term health impacts of wildfire smoke.
Related: Politico Reports: Cancer is The Unseen Danger in The Los Angeles Fires
Resources:
Gao Y, Huang W, Xu Z, Xu R, Gasevic D, Liu Y, Yue X, Zhou G, Zhang Y, Song J, Liu H, Guo Y, Li S. Wildfire-related PM2.5 and cause-specific cancer mortality. Ecotoxicol Environ Saf. 2024 Oct 15;285:117023. doi: 10.1016/j.ecoenv.2024.117023. Epub 2024 Sep 14. PMID: 39278001.
Hwang J, Chong NS, Zhang M, Agnew RJ, Xu C, Li Z, Xu X. Face-to-face with scorching wildfire: potential toxicant exposure and the health risks of smoke for wildland firefighters at the wildland-urban interface. Lancet Reg Health Am. 2023 Mar 26;21:100482. doi: 10.1016/j.lana.2023.100482. PMID: 37008196; PMCID: PMC10060103.
Rice RB, Boaggio K, Olson NE, Foley KM, Weaver CP, Sacks JD, McDow SR, Holder AL, LeDuc SD. Wildfires Increase Concentrations of Hazardous Air Pollutants in Downwind Communities. Environ Sci Technol. 2023 Dec 19;57(50):21235-21248. doi: 10.1021/acs.est.3c04153. Epub 2023 Dec 5. PMID: 38051783; PMCID: PMC10862657.
VoPham T, Jones RR. State of the science on outdoor air pollution exposure and liver cancer risk. Environ Adv. 2023 Apr;11:100354. doi: 10.1016/j.envadv.2023.100354. Epub 2023 Feb 12. PMID: 36875691; PMCID: PMC9984166.
