The January 2025 wildfires that tore through Pacific Palisades, Topanga Canyon, and the surrounding hillside communities left behind more than scorched homes and displaced families. Years later, residents who have returned, are now asking a question their doctors are taking seriously: what does prolonged wildfire smoke exposure actually do to the lungs over time, and when does damage become something worse?

The Air That Stayed Behind

Wildfire smoke is not normal campfire smoke. When structures burn, they release a toxic cocktail that includes benzene, formaldehyde, heavy metals, asbestos from older homes, and fine particulate matter known as PM2.5. These microscopic particles are small enough to bypass the nose and throat entirely, embedding themselves deep in lung tissue where the body has no mechanism to expel them.

For residents along the Palisades ridgeline and throughout the canyon corridors, the exposure window was not a matter of hours; it stretched across days and, in some cases, weeks as structural debris continued smoldering and wind patterns pushed smoke back into adjacent neighborhoods.

Why Oncologists Are Watching

The connection between prolonged particulate exposure and lung cancer risk is not theoretical. The International Agency for Research on Cancer classifies outdoor air pollution (including wildfire-generated PM2.5) as a group 1 carcinogen, the same category as tobacco smoke. Research following the 9.11 first responders, who were exposed to pulverized building materials in Lower Manhattan, documented elevated rates of lung malignancies appearing 10 to 15 years after exposure.

Wildfire-related lung injuries tend to be underdiagnosed because patients feel recovered within weeks. Coughing subsides, and shortness of breath fades. But cellular-level inflammation and DNA damage in airway tissue can persist silently long after symptoms resolve, creating conditions that may take years to manifest clinically.

Who is Most at Risk in These Neighborhoods?

Not every resident faces the same level of risk. There are several factors that compound wildfire smoke exposure into a significantly elevated concern. Former smokers who lived or worked near the burn zones face a multiplied risk profile – prior tobacco-related cellular damage makes lung tissue more susceptible to carcinogenic particulates. Residents over 50 years of age who spent extended time outdoors during the fires without adequate protection are also considered a higher-risk.

Children and long-term canyon residents who have experienced multiple fire seasons (the Woolsey Fire in 2018, the Creek Fire impacts, and the 2025 Palisades disaster) carry a cumulative exposure history that few have had the chance to fully study. The data on repeat-season wildfire residents is still emerging.

What to Ask Your Doctor Now

Canyon community residents who were directly in or near the fire zones should request a pulmonary function test at their next primary care visit, regardless of whether they currently have symptoms. Those who meet the age and smoking history criteria for low-dose CT screening, namely adults 50 to 80 with a 20 pack-year history, should make that appointment immediately and mention the wildfire exposure explicitly.

Wildfire smoke does not appear in standard screening eligibility criteria, but physicians in affected areas are being urged by state health officials to treat significant exposure as a relevant clinical factor.