AFFF and thyroid cancer

A Mount Sinai team reported that when n-PFOS levels in blood doubled, the rate of thyroid cancer diagnosis rose by 56%. n-PFOS belongs to the PFAS family and appears in certain firefighting foams.

Only a small group took part, though. The research compared 88 thyroid cancer patients with an equal number of cancer-free volunteers. The scientist leading the work now intends to follow up with a study across the U.S. armed forces, asking whether troops exposed to PFAS in firefighting foam show higher thyroid cancer rates. No results have been reported yet.

Health authorities haven't reached a shared view. ATSDR, a federal health agency, found no consistent evidence tying PFAS to thyroid disease. The National Academies called the evidence limited or suggestive. ATSDR also notes that for every health effect it lists, proof of cause and effect is still missing.

Back in 2012, a court-appointed body known as the C8 Science Panel reported a "probable link" between thyroid disease and PFOA. PFOA comes from that same PFAS family. There, the phrase "probable link" described a connection that seemed more likely than not. The panel tied 6 conditions to PFOA with probable links, and thyroid cancer wasn't on that list.

Thinking has shifted since then. In 2020, some former panel members described the evidence on PFOA and thyroid as suggestive but uneven. A 2025 review by authors at Roux, a consulting firm, argued that recent research backs no causal relationship, which pushes back against the panel.

One big federal PFAS health study won't settle anything for firefighters. It leaves out people exposed at work, so what it finds applies to drinking water, not to the fire service.

Out of 50 states, 41 have a presumption law for firefighters. These laws presume that certain cancers are job-related for firefighters, but coverage depends on each state's rules.

Thyroid cancer appears on fewer of these lists than many other cancers. A dozen states, Connecticut, Florida, Iowa, Maryland, Michigan, Nevada, New Mexico, New York, Rhode Island, Utah, Vermont and Virginia, name it outright. Another 18 states extend coverage when the illness traces back to the job.

A few states do things differently. Delaware, Georgia, Mississippi and South Carolina offer a cancer insurance payout rather than a presumption. Three others (Arkansas, Kentucky and North Carolina) provide a death benefit for line-of-duty deaths, South Dakota's rule covers pensions only, and Hawaii covers lung disease alone.

For federal firefighters, the law lists thyroid cancer among 14 covered cancers and requires 5 years of service.

Veterans have a tougher road. A veterans' law firm reports that the VA has no presumptive conditions tied to AFFF exposure, so a veteran has to show the service connection, say with a nexus letter from a doctor.

In December 2018, lawsuits over foam injuries were gathered into a single federal case group based in South Carolina, where Judge Richard M. Gergel presides. The count of pending claims stood near 15,264 in the fall of 2026.

During spring 2024, the court carved out its own track for test cases involving thyroid and liver cancer. A test trial means one early case picked to give a preview of how similar cases might turn out. On June 20, 2025, the court held a Science Day where experts spoke to the question of whether PFAS causes these cancers.

Results from a test trial won't decide your case by themselves, but the court's rulings on issues common to everyone still matter. Proposals for the next round of test cases, thyroid disease and ulcerative colitis among them, must be submitted by November 20, 2026.

There is still no personal injury settlement, and talks ordered by the court with a mediator are ongoing. The billion-dollar public water settlements do not provide individual payouts for thyroid cancer or other diseases.

The opening test trial, a kidney cancer matter scheduled for October 2025, was called off, and no new date has been chosen. In June 2026 the judge named a special master, Margaret Seymour, to deal with requests to dismiss cases, and he anticipates that defendants will seek dismissal of around 8,000 lawsuits.

An order issued August 15, 2025 opened a filing window of three weeks that shut in early September 2025. Anything filed once that window passed has to clear extra hurdles, so timing matters. To see what your state covers, use the checker on our home page or your state's page, and call the claims line with any questions about your claim.