What to Know Researchers have found potentially carcinogenic compounds that are used as an agent in most American firefighters’ turnout gear.

The EPA phased out domestic manufacturing of PFOA amid concerns of human health and environmental impact.

A chemist says the federal government has been “remarkably absent at the moment” in researching the connection to cancer in firefighters.

For 28 years, Paul Cotter pulled on his turnout gear to battle thousands of fires as a Worcester firefighter.

“We went to every fire in the city,” he said.

His wife, Diane, called him “a fireman’s fireman.”

More than four years ago, he got the worst call of his career. He remembers sitting in his kitchen as he got the news: a pre-op physical detected prostate cancer.

“It took me three days to tell my wife,” he said. “I couldn’t tell her.”

Four years later, after treatment, he is cancer free. But with no family history of cancer, Diane Cotter said she began asking questions. And those questions led her to the protective overcoat and pants firefighters wear on every call.

“Cancer-causing agents do not start at a fire,” Paul Cotter said. “We have chemicals in our gear.”

For years discussion and research into high cancer rates among firefighters have focused on the smoke as a possible cause.

But researchers have found potentially carcinogenic compounds that are used as a water-repellent agent in most American firefighters’ turnout gear, as well as in fire suppressing foam.

And federal documents from DuPont, the giant chemical producer and a major manufacturer of the compounds, show that the company researched their impact on humans at least as far back as the 1990s, and feared what regulation could mean for revenue.

No study has been done specifically on a potential link between cancer and use of perfluorinated alkylated substances (PFAS), a group of chemicals that includes perfluorooctanoic acid (PFOA), in firefighters’ uniforms.

So Diane Cotter went looking for answers.

She took her hunch and turned it into a lead herself, sending samples of new, never worn turnout gear to be tested.

“Almost instantly we got a signal, and that doesn’t usually happen in science,” said Graham Peaslee, a nuclear chemist at the University of Notre Dame.

He tested the gear for PFAS, a group of chemicals that some studies have shown to increase the risk of a range of cancers, including prostate cancer.

“There was a lot of it there,” Peasley said.

According to the Centers for Disease Control and Prevention, some studies have found workers producing, and exposed to, PFAS have an increase in diseases including prostate, kidney and testicular cancer.

“The International Agency for Research on Cancer (IARC) has classified PFOA as possibly carcinogenic and EPA has concluded that both PFAS and PFOS are possibly carcinogenic to humans,” the CDC wrote in a 2017 fact sheet to physicians. “Some studies have found increases in prostate, kidney, and testicular cancers in workers exposed to PFAS and people living near a PFOA facility.”

It also noted that more research is needed to clarify what kind of link there is between the compounds and cancer, and that other studies found no correlation.

The CDC’s National Institute for Occupational Safety and Health launched a comprehensive multi-year cancer study of 30,000 firefighters in 2010. Among the results, the agency found that “there were more cases of certain cancers among younger firefighters. For example, firefighters in our study who were under 65 years of age had more bladder and prostate cancers than expected.”

The EPA phased out domestic manufacturing of PFOA amid concerns of human health and environmental impact.

The U.S. Department of Defense identified 126 military bases where PFOA from firefighting foam had contaminated local water.

PFOA specifically received attention internationally as well.

In 2006, the European Chemical Agency restricted the use of PFOA in textiles including firefighting turnout gear, and in 2012 the chemical was designated a “substance of very high concern,” meaning it is subject to restrictions in Europe.

“We are at the point in time where the firefighting community, emergency responders, the folks that may have been exposed to these materials for decades ought to be really demanding this information,” said Robert Bilott, an environmental attorney who has been fighting use of the chemical.

The New York Times has called Bilott “DuPont’s worst nightmare” after he successfully sued the chemical giant, one of the primary domestic producers of PFOA, 17 years ago over water in West Virginia polluted with PFOA.

A year ago, Bilott sent a 196-page letter to the EPA, the CDC, the U.S. Attorney General’s Office, and the Agency for Toxic Substances and Disease Registry, an agency in the U.S. Department of Health and Human Services, demanding national testing and studies of firefighters exposed to PFOA.

“Even though the toxicity of these chemicals has been well-known by certain manufacturers for quite some time, it is not something that was told to the people who are actually using these materials,” Bilott said.

Public documents show that DuPont has researched potential links between PFOA and cancer.

In 1997, a paper written by DuPont scientists show they studied PFOA and potential connection to testicular and pancreatic tumors. The conclusion was that the origin of the cancers was “not completely understood,” but “the relevance to humans cannot be completely ruled out.”

Meanwhile, DuPont, in an annual report filed with the federal Securities and Exchange Commission in 2006, warned shareholders that attempts to regulate PFOA would hit them financially.

“Products currently manufactured by the company representing approximately $1 billion of 2009 revenues could be affected by any such regulation or prohibition,” the company wrote in its report. “DuPont has established reserves in connection with certain PFOA environmental and litigation matters.”

Dian Cotter said she feels DuPont has deceived her.

“DuPont stands shoulder to shoulder with us at your firefighter cancer symposiums and they’ve never once mentioned PFOA in the amounts we now know to be in the turnout gear,” she said.

In a statement, DuPont said it “no longer makes, uses or buys PFOA, and cannot comment on these materials.”

The company referred NBC10 Boston to Chemours, a chemical company and spin-off of DuPont that makes a PFOA replacement called Gen-X. Chemours did not respond to repeated requests for comment.

Peaslee said the federal government has been “remarkably absent at the moment” in researching the connection to cancer in firefighters.

For example, $100 million was just been approved in the Defense Department’s budget for a nationwide health study and to fund a cleanup of PFAS in the water around military bases. But firefighters were not included in the study.

That omission will be addressed at a hearing by the U.S. Senate’s Committee on Homeland Security in Washington, D.C., Wednesday.

Meanwhile, some states are regulating PFOA on their own.

Washington State was the first to specifically pass a law designed to protect firefighters. That law bans the chemical from firefighting foam and requires any fire gear with the chemical to carry a warning.

And the Boston Fire Department plans to send turnout gear to be tested this fall.