At the end of a long shift, black stains cover yellow Nomex shirts, telling the story of grueling hours spent on the fireline. Across the West each summer, wildland firefighters collapse into sleeping bags still dirty from the day’s work, prioritizing a hot meal and sleep over showers and clean clothes. In a dangerous job riddled with hazards, dirt may be the least of their concerns.

But is there a danger lingering on their skin?

At the Garnet Fire in California’s Sierra National Forest, a team from the Federal Firefighter Health and Wellbeing Program – joined by Persephone Whelan, Forest Service branch chief for operational risk management – set out to answer that question. By collecting skin wipe samples from dozens of firefighters, they hope to understand long-term health risks and rethink fireline hygiene.

“When you’re on the fireline, you sweat, you move through smoke and dirt and ash,” said Whelan. “You get dirty pretty fast, but is this just grime or could it be something more dangerous?”

Firefighters routinely encounter toxic compounds called polycyclic aromatic hydrocarbons, released during combustion. These chemicals can enter the body through inhalation and skin absorption, even when protective equipment is worn. While previous studies focused on inhalation, this pilot project investigated skin contamination, an understudied risk that may help explain the elevated cancer risk among wildland firefighters.

Finding what’s getting on to firefighters’ skin and whether it’s getting into their bodies was anything but simple. Firefighters move constantly between bases, camps and areas of the fire. The team needed access to them both before and after their long shifts. They also had to overcome the challenges of powering freezers for preserving samples and conducting their work without disrupting the firefighting effort.

Whelan worried most about finding willing firefighters to participate.

“I thought they’d say, ‘Hell no,’” she said. “This is your neck getting wiped down by somebody you don’t know, your hands and your legs from the knee to the boot, so part of me thought they’re not going to let us do it.”

But the response surprised the team. They received full support from the Garnet Fire managers and dozens of firefighters volunteered. They showed up to provide samples, even before eating after an exhausting day. They gave their time and trust in pursuit of answers that could change the future of the job.

“They were very supportive,” said Whelan. “They put down what they were doing and said ‘Absolutely, what can we do to assist with this?’ It made me proud of our firefighting community.”

First of its kind

The Garnet Fire evaluation was the first of its kind. Over five days, the interagency team collected samples from 35 federal firefighters – hotshots, helicopter and engine crews, as well as resource advisors. 210 samples were taken before and after shifts, targeting the neck, jawline, hands and lower legs, and were sent to be analyzed for 17 polycyclic aromatic hydrocarbons including known carcinogens such as benzopyrene and chrysene.

Because federal legislation recognizes certain cancers, heart disease and long-term conditions as occupational diseases for wildland firefighters, this project is part of fulfilling the mandate to more deeply investigate those long-term health effects.

“This is about building a medical surveillance program,” Whelan said. “But first, we need to understand what we’re exposed to.”

The review also challenges a long-standing fireline ethos that being dirty is a mark of hard work.

“We have got to find other ways to identify a hard-working firefighter,” Whelan said.

She envisions a future where showers, clean personal protective equipment and even decontamination protocols could become a standard part of the workday. Working in remote locations makes this challenging, but even using wet wipes would be an improvement.

Lab results are still pending, and each participant will receive their own data with expert analysis. If polycyclic aromatic hydrocarbons are found in high concentrations, the next step is to determine whether they penetrate the skin and what that means for long-term health.

Sparking a cultural shift

While not all polycyclic aromatic hydrocarbons are proven to be carcinogens, many have high toxicity and are pro-carcinogenic, meaning they can cause cancer if the body metabolizes it. Many highly toxic polycyclic aromatic hydrocarbons are also not included in routine environmental monitoring due to limited data.

“Not a lot of research has been done on this for the wildland fire community,” she said. “I’m really curious about what is really happening on our skin and how can we make this work safer.”

The pilot study could spark broader investigations, influence personal protective equipment guidelines and reshape fireline protocols. More importantly, it could empower firefighters to make risk-informed decisions about their long-term health and exposure.

Whelan is hopeful but stressed that this type of workplace evaluation takes time.

“There is a lot of noise out there – products and gimmicks from a burgeoning industry promising a quick fix for firefighters,” she said. “But we have an interagency team of experts dedicated to real science. It’s incremental, but it’s happening.”

For Whelan and the Forest Service, success isn’t just cleaner skin or better data. It’s a cultural shift that values health as much as toughness.

*Editor’s Note: January is National Firefighter Cancer Awareness Month. Firefighters can help improve research about occupational cancers by participating in the National Firefighter Registry for Cancer https://www.cdc.gov/niosh/firefighters/registry/index.html.

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