When San Francisco firefighter Tony Stefani developed a rare cancer in 2001, he used up all of his sick and vacation leave during his treatment. Two hundred of his fellow officers donated their own sick time so he could continue collecting a paycheck while he recovered. In order to enroll in disability benefits, he had to go before a worker’s compensation judge and document that he had contracted his disease from his line of work.

Mounting evidence suggests many firefighters do get cancer from the toxins they encounter in burning homes, but the connection can be difficult to prove. Nonetheless, Stefani was eventually awarded disability status, and other firefighters in San Francisco might now have an easier time of it. Last year, the city passed a law saying that when a firefighter gets any form of cancer, it will be presumed to be a result of his or her job.

But firefighters in other states and cities lack the same protections. Although firefighting is associated with a far greater risk of developing cancer than many other professions, 14 states don’t recognize the link between cancer and firefighting when it comes to awarding worker’s comp and medical benefits. In those states, firefighters must prove that their cancer originated at specific fires. Firefighters’ groups, such as the International Association of Fire Fighters, argue that can be impossible to track because the carcinogens that first responders are exposed to accumulate over time.

In Kentucky, firefighter Chris Miller also relied on donated sick time when he was diagnosed with lymphoma 10 years ago. “I had no sick time, I had nothing to cover me,” he said. “I would have wound up off work, no pay, COBRA [health insurance] coverage, shelling out $1,000 per month.” His union is currently fighting for a so-called “cancer presumptive” law in his state.

Last year in Georgia, a state without a presumption law, the city of Fairburn fired 36-year-old Jason Trotter, an eight-year veteran of the fire department, after he was diagnosed with Hodgkin’s lymphoma and took months off work to undergo chemo.

Firefighters’ advocates argue that the burden of proof is too steep for a disease as complex as cancer. To get disability coverage in North Carolina, for example, “a firefighter would have to prove he contracted the cancer on a particular day at a particular fire,” the Greensboro News and Record reported last year. Tom Brewer, a professional firefighter in Charlotte, North Carolina, said his department is currently lobbying for cancer-presumptive legislation in the state. “Without the law, you have to prove which fire you caught it at,” he said. “It's hard to prove that way.”

In Florida, the firefighters’ union attempted to push through cancer-presumption bills in 2003, 2004, 2007 and 2008, but they all died in committee. Several large, national studies have shown a link between firefighting and cancer, but to pass the legislation, Florida firefighters must gather state-specific data that confirms the association.

In Ohio, Senator Tom Patton has proposed presumption bills to the Ohio legislature three times, but the past two attempts failed. (He’s trying again this year.)

The laws tend to be opposed by city and municipality lobbying groups, who fear they would be too expensive. Even in some states that have enacted them, the measures have fallen short because of a lack of funding. Michigan passed a law in January creating a fund to cover firefighters who get cancer on the job. But as of April, the legislature had yet to put any money into the fund, according to a report from Michigan Radio. What’s more, the law excluded breast cancer, which affects female firefighters at higher rates.

The absence of presumption laws has led to the rise of apps that aim to help firefighters track their exposure to carcinogens. With Exposure Tracker, for example, firefighters can log the number of fires they’ve fought, as well as the ages of the burning structures they enter—information that might help trace their exposure to substances like asbestos.

I asked Brewer, the North Carolina firefighter, if the studies showing that firefighting is correlated with cancer, combined with his state’s lack of a presumptive law, has dampened interest in joining the force.

Not really, he said.

“We've grown accustomed to accepting that it's part of the risk of the career,” he said. “We know when we get into this profession that we don't live as long as the general public, but at the same time, it's what we want to do.”