When Tony Stefani sees the hellscape images of firefighters battling drought-driven blazes in California and elsewhere, he sees more than the strain and exhaustion. He sees a grave and growing threat to the long-term health of brave public servants.

Stefani is a firefighter himself, a veteran of San Francisco Fire Station 1, among the busiest fire precincts in the United States. In 2001, at 49 and in peak physical condition, he was diagnosed as having transitional cell cancer in his kidney. His surgeon, Marshall Stoller of the University of California at San Francisco (UCSF), immediately suspected that chemical exposure from the burning contents of modern buildings was to blame. Since then, Stefani has made it his mission to alert firefighters to the risks they face, and push for their safety, through the organization he founded: the San Francisco Firefighters Cancer Prevention Foundation.

Research sponsored by Stefani’s group at leading Bay Area universities has deepened understanding of the health risks of smoke exposure. At Station 1 alone, four additional cases of genitourinary cancers have been found since Stefani’s diagnosis some 20 years ago — three of them fatal. A study by UCSF turned up three more cases among roughly 1,100 firefighters, a rate far in excess of the general population's, according to Stefani.

A larger study, looking at the cause of death of nearly 30,000 firefighters between 1950 and 2009 in three major cities, found elevated rates of many cancers. As the field has opened to women, Stefani told me during a phone call recently, tentative data show rates of breast cancer up to six times higher than in the general population.

Stefani fears that the epic forest and brush fires consuming whole subdivisions and towns in the rural and semirural West will expand the cancer menace like — well, like wildfire. Urban firefighters, he points out, wear breathing apparatuses and mostly fight fires in a single building. In battling wildfires, by contrast, unprotected firefighters often work 12-hour shifts, or longer, for weeks at a time as blazes chew through dozens, hundreds, even thousands of buildings.

When we spoke, the enormous Dixie Fire in California — the largest single-source fire in the state’s recorded history — had just consumed most of the town of Greenville. The historic Gold Rush settlement had looked from the outside like a rustic movie set, but inside, the buildings were the comforts of contemporary life: computers, televisions, refrigerators and freezers, insulation, plastics, the rubber compounds in tires, and so on. When burned, these release highly toxic fumes.

What happened to Greenville has become almost routine in Northern and Central California. In 2017, the Tubbs Fire destroyed more than 5,600 buildings in wine country. In 2018, the Camp Fire wiped out most of the towns of Paradise, Concow and Magalia.

“There are petroleum-based products and heavy metals in every home and business,” Stefani told me. “We’ve had researchers taking blood samples from firefighters who fought the Tubbs and Camp fires, and we’re finding elevated rates of carcinogens of all kinds. Everything we see in urban firefighters is slamming the men and women fighting these wildfires — but worse. Far worse. There’s no escaping for these firefighters; it’s a few hours of rest and then right back into the smoke.

“I don’t know how to say it except that they’re taking a total [butt]-whipping out there,” he said.

It’s a complicated problem. Training is variable: Wildland firefighters come from city fire departments and the U.S. Forest Service but also include seasonal workers and even prison inmates. Limiting their time on the line is impractical given the extreme shortage of available crews. Self-contained air supplies, which partially protect urban firefighters, won’t work on wildfires. They’re too heavy, too costly and too limited — a tank of air lasts less than an hour.

And yet, “something has to be done,” Stefani told me.

Some places to start: Communities need to make the “urban interface” — the places where cities and towns meet wilderness — more fire-resistant. Landscaping, brush clearing and tree thinning can all help. Firefighters need to be educated concerning the risks. Strategies for containing wildfires should take smoke exposure into account. An insurance pool of some sort should be created to provide targeted benefits to wildland firefighters whose service leads to health crises or the inability to work.

There’s a job for inventors to develop protective masks suitable to the demands of a highly punishing job. Something you can breathe in while humping heavy equipment up a mountainside on a hot summer day, yet able to filter out the most toxic airborne particles. “A red bandanna over your mouth won’t cut it,” Stefani said.

First things first: naming the problem. “People know about the fires and the towns that are burning,” Stefani said. “Now they need to know what it’s doing to the men and women out there fighting for us.”