What’s the link between wildfires and cancer?

Jun 3, 2025

Wildfires are becoming increasingly common and severe; wildfire smoke poses significant health risks to people living nearby even beyond the immediate physical danger. In addition to factors like extreme heat and droughts, wildfires contribute to worsening air quality. In fact, the American Lung Association (ALA) says nearly half (46%) of the U.S. population lives in areas with unhealthy levels of air pollution—nearly 25 million more compared to 2024’s findings.¹

One of the lesser-known but serious risks associated with wildfires and worsening air pollution is the risk of cancer. Understanding this connection and taking steps to stay safe can help reduce your risk, even if you live in an area prone to wildfires.

How does wildfire smoke increase my cancer risk?

Wildfire smoke contains a mixture of gases and fine particles from burning vegetation, building materials and other substances. This smoke can include harmful chemicals such as polycyclic aromatic hydrocarbons (PAHs), benzene, formaldehyde and heavy metals. Long-term exposure to these pollutants has been linked to an increased risk of developing cancer, particularly bladder, skin and lung cancers. (It can also be harmful to bone marrow.)

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I live in an area where wildfires are common. How can I protect myself?

The top priority when there is a wildfire is making sure you and your family are safe from the fire itself. Always heed evacuation orders from local authorities. Leaving the area promptly can also significantly reduce your exposure to harmful smoke and other hazards.

If you are staying put, protecting yourself from the wildfire smoke is crucial to reducing your cancer risk. Here are some practical steps to stay safe:

Stay inside: If it’s smoky outside but you are not ordered to evacuate, it’s important to continue staying indoors.
Monitor air quality: Stay informed about the air quality in your area by checking resources like airnow.gov or your local weather app:
- AQI 0–50 (Good): Safe for all activities.
- AQI 51–100 (Moderate): Generally safe, but sensitive groups (children, elderly, those with asthma) should be cautious.
- AQI >100: Limit outdoor activities, especially for sensitive groups.
Create a clean air space: Avoid burning candles, lighting incense or using gas stoves indoors during wildfire events. Designate a room in your home that can be closed off from outside air. To keep the air in this room clean, use an air purifier and close all doors and windows—then spend the majority of your time indoors in this clean air room.
Use respiratory protection: If you must go outside, wear an N95 mask to reduce smoke inhalation or limit exposure. Regular masks may not provide adequate protection against fine particles in wildfire smoke. Children under 2 years old should not wear face masks or coverings, as they can pose a risk of suffocation.

After a wildfire, smoke can remain in the air for several days. Check outside to see if conditions have improved—there should be no visible haze, ash or soot, and the air should be free of any smoky odor. Wait for local authorities to declare it safe to resume normal outdoor activities and continue to check the AQI in the days and weeks that follow. If the AQI continues to indicate unhealthy levels, limit outdoor activities.

What about firefighters who have fought fires over a long period of time? Are they at increased risk?

Firefighters may be at increased risk for some cancer types due to smoke inhalation and the inhalation of other toxic substances (like carbon monoxide and asbestos). There is sufficient evidence from the International Agency for Research on Cancer (IARC) for firefighting-related exposures known to cause lung cancer and other types of cancer.

Research is ongoing to determine possible links between firefighters and developing cancer. Organizations like the International Association of Firefighters and Hunter Seven Foundation are devoted to finding resources and information to prevent and treat cancer and other serious health problems affecting firefighters.

What signs or symptoms should I be on the lookout for?

Pay attention to your body and any unusual changes. People with lung cancer often do not experience symptoms in the early stages, but be on the lookout for:

A cough that does not go away or worsens
Coughing up blood
Constant chest pain
Repeated pneumonia or bronchitis
Weight loss and loss of appetite
Hoarseness lasting a long time
Wheezing or shortness of breath
Feeling very tired all the time

Poor air quality can trigger a range of symptoms, such as:

Irritation of eyes, nose and throat
Coughing
Phlegm
Chest tightness
Shortness of breath

Regardless of whether you live in an area prone to wildfires, if you begin to experience any of these symptoms, talk with your health care provider right away. Your provider may recommend a lung cancer screening—finding lung cancer early is the best way to achieve better health outcomes.

By staying proactive and informed, you can help protect yourself and your loved ones from the hidden dangers of wildfire smoke. Your health and well-being are worth the effort. Stay safe and visit preventcancer.org for more ways to reduce your risk of cancer.

¹https://www.lung.org/research/sota/key-findings