When Timothy Ingalsbee thinks back on his days in the 1980s and '90s fighting wildfires in the Pacific Northwest, he remembers the adventure of jumping out of a helicopter into the wilderness, and the camaraderie of being on a fire crew.
"We just slept in a heap," he says, "on the ground under the stars, or smoke-filled skies."
But Ingalsbee, who went on to found the Eugene, Ore.-based Firefighters United for Safety, Ethics and Ecology, doesn't like to remember all that smoke.
Some seasons, he says, "I lost my sense of smell and taste for several months. It wasn't until maybe the next spring it started coming back."
As wildfires have grown more frequent and intense in recent years, communities have complained about the health impact of all that smoke, and the economic hit to recreation and tourism. But residents can seek relief by staying indoors and using air filters or masks.
These aren't options for the wildland firefighters fighting those blazes, or managing prescribed burns aimed at preventing them. They endure smoky conditions rarely experienced in residential communities, and it's an occupational hazard scientists and fire agencies are just beginning to understand.
Long hours of exposure with limited protection
The hazards have long been known for those who fight fires in buildings. Studies have shown they have elevated risks of cancer, heart and lung disease, and even mental health issues, says Rick Swan, a 30-year veteran of CalFire, and health and safety director with the International Association of Firefighters, a labor union.
But wildland firefighters have largely been left out of the research.
"Everyone used to say, 'It's just a barbecue fire. It's just, you know, wood. It's no big deal,' " he says.
Now, it's known that forest fire smoke is full of compounds and components that are regulated by the Environmental Protection Agency.
Wildland firefighters and crews are exposed to fine particulate matter that can absorb deep into the lungs. They breathe carbon monoxide that can cause a significant and immediate loss in cognitive function.
In addition, there are a host of other toxins such as acrolein, nitrogen dioxide, benzene and formaldehyde in the smoke. There's also the potential for exposure to smoke laced with chemicals from herbicides that were applied to forests before they caught fire.
Researchers with the U.S. Joint Fire Science Program have found that workers are exposed to the highest levels of particulate matter when they're holding fire lines and working mop-up after a fire has burned through.
And the smoke exposure often doesn't end at the fire zone.
"Some of the worst air can be in fire camp, where you're supposed to go for rest," Ingalsbee says. Often, the camps that house and feed fire workers and support personnel are located in valley bottoms, where wildfire smoke can get trapped.
"You wake up in fire camp with people coughing and hacking up," he says. "They call it camp crud."
Through all this, wildland firefighters have limited personal gear for respiratory protection.
"This is 2019. We've been using a bandana for I don't know how many decades, and that is the best we have to offer?" Swan says.
A bandana is the only respiratory protective equipment recommended for firefighters to carry. And the EPA and many other health agencies warn that it doesn't actually help reduce particulate exposure.
But experts say there's no easy alternative. The basic N95 respirators available to the general public don't hold up to the intense conditions of a fire. And the respirators that structural firefighters use are heavy, reduce vision and can only supply clean air for a short period of time. Wildfire shifts are generally 12 hours.
What's more, "their respiratory demands are similar to those people engaging in athletic events," says Mike DeGrosky, Fire Protection Bureau chief with the Montana Department of Natural Resources and Conservation. "You put any kind of restrictive thing over your nose and mouth and you're decreasing your oxygen update, which decreases your muscle abilities, your cognitive abilities."
Researching long-term impacts
Only recently have federal fire agencies started considering the long-term health effects of chronic smoke exposure for wildland firefighters.
A 2017 review of research on wildfire smoke exposure by the Joint Fire Science Program found the impacts are "largely unknown," although an analysis done as part of the review did indicate that "inhaled particulate matter can increase the risk of premature mortality from heart disease or cancer."
Wildland firefighters are a difficult group to study, in part because of the nature of the work. They often work seasonally or part-time. The work is physically demanding, and many don't stick with it long-term.
"We know that wildland firefighters experience a range of exposures, not just smoke but disrupted sleep, working under intense conditions and difficult terrain," says Curtis Noonan, an epidemiologist at the University of Montana. "And so we know all of these exposures are associated with health outcomes, but they just haven't been looked at yet for wildland firefighters."
Noonan and his colleague Erin Semmens are researching some of these health outcomes.
Interior Department firefighters are required to undergo an extensive physical every three years. The researchers are using these medical records and employment data showing how many days and years firefighters have been working on fires to determine any links.
"So if they're seeing some cardiovascular impacts, maybe that is something that needs to be screened more frequently," Semmens says.
In the meantime, wildland firefighters are facing another fire season.
Seeking a culture shift
Swan, the union safety director, would specifically like to see more attention paid to the smoke exposure crews experience on prescribed burns, fires set on purpose to reduce the fuel that feeds larger outbreaks.
Fire scientists with the Joint Fire Science Program, which includes the U.S. Forest Service as a member, have found that prescribed fire crews' exposure to particulate matter is likely to exceed recommended occupational exposure limits.
Oregon Public Broadcasting was denied access to a U.S. Forest Service prescribed burn near Ashland for this story. And Swan says he's seen a general reluctance to take on the issue of respiratory protection. "A lot of folks are sticking their heads in the sand," he says.
He blames, in part, a culture that glorifies the image of a "real" firefighter: dirty, and willing and able to work long hours, despite what it may mean for long-term health. "That culture gets us into trouble more than anything," Swan says. "It doesn't allow us to get out of our own way."
Despite this, things are slowly changing.
For the first time this year, the national group responsible for developing wildfire training materials has included a unit on the dangers of smoke exposure as part of its annual health and safety refresher course.
Last year President Trump signed legislation to create a "national firefighter registry" that will help the Centers for Disease Control and Prevention track links between on-the-job exposures and cancer. Congress appropriated $1 million to implement the program.
The international firefighters union says it's working with the U.S. government to ensure that the term "firefighter" is applied as loosely as possible so it includes wildland firefighters.
Ingalsbee, the former Northwest firefighter, says he doesn't regret his time working wildfires and dealing with the smoke, even though he's noticed his own lung capacity suffer significantly since leaving the woods.
But he predicts it will take more than a shift in training to make sure wildland firefighters are protected, not only on the job but long after their careers have ended.
"Veterans of military conflict get health services long after they're out of uniform," he says. "Perhaps our 'wildfire warriors' should be provided health services after they're out of uniform."
Reporting for this story was supported by the Institute for Journalism and Natural Resources.