DURHAM, N.C. (WNCN) – In 2019, the International Association of Fire Fighters said more than 75 percent of the names added to their memorial wall died of occupational cancer.

The association cites occupational cancer as the leading cause of line-of-duty deaths.

It’s an issue fire departments have struggled to find a solution for.

The National Institute of Occupational Safety and Health reported firefighters have a 9 percent higher risk of being diagnosed with cancer and a 14 percent higher risk of dying from the disease than the general adult U.S. population.

Researchers at Duke University are developing a new tool to help track firefighters’ exposures to cancer-causing chemicals and determining where and when the risks might be greatest. The tool is a $1 a silicone wristband.

“It turns out that ordinary silicone wristbands, like the ones sold in stores, absorb the semi-volatile organic compounds you’re exposed to while you’re out in the world,” said Jessica Levasseur, a PhD student at Duke’s Nicholas School of the Environment, who led the study.

Duke University said the study came about when the Durham Fire Department approached Duke researchers for help identifying exposure risks its firefighters faced.

Levasseur said the specific reason why firefighters have a higher chance of cancer diagnosis are unknown.

”Is it caused by exposure to one chemical or a mix of them? Is it something they breathe in while working in fires or being near them? Or something else? There are lots of risk factors and potential routes of exposure, and we wanted to see if silicone wristbands could be a practical tool for disentangling them,” Levasseur said.

During the study, 20 firefighters were asked to wear the wristbands while working a typical six-day shift. They were also asked to wear them while off duty to get each firefighter’s baseline exposures.

Each wristband was analyzed for 134 different chemical compounds that have been linked to increased incidence of certain cancers.

“Seventy-one of these chemicals — including seven PFAS, which to our knowledge have never previously been detected using wristbands — were found in at least half of the bands,” Levasseur said.

Levels of PAH, brominated flame retardants and organophosphate esters were 0.5 to 8.5 times higher in the wristbands worn while on duty than in those worn while off duty. The study said this suggests that just being a firefighters are exposed to more of these compounds regardless of whether they respond to a fire while working.

Bands worn by firefighters on days they actively fought a fire also contained 2.5 times more PFOS, a type of PFAS. This suggests that exposure to these contaminants is strongly associated with active firefighting, Levasseur said.

Duke researchers said wristbands worn on off-duty days contained higher levels of phthalates and pesticides.

“Conducting follow-up research with a larger population will help pinpoint the exposure sources that contribute to firefighters’ risk for cancer and assess exposure risks that may be related to chemicals off-gassing from their gear or materials in their firehouse, which we did not examine,” Levasseur said.

The peer-reviewed findings were published April 26 in the journal Science of the Total Environment.

Levasseur’s co-authors on the new study were Dr. Kate Hoffman, Dr. Nicholas J. Herkert, Dr. Ellen Cooper, Duncan Hay and Dr. Heather M. Stapleton, all of Duke’s Nicholas School of the Environment.

Funding came from the Duke University Cancer Institute and the National Institutes of Health. Levasseur also receives support for her research as a Robert Wood Johnson Foundation Health Policy Research Scholar.