Thyroid cancer AFFF claims

PFOS exposure increases the risk of thyroid cancer in firefighters by 56%

"Forever chemicals", also known as PFAS, have a strong ability to interfere with thyroid function. Because these substances are endocrine disruptors, they can affect the body by mimicking fatty acids. They interfere with the hormone system, making civilian and military firefighters exposed to AFFF more prone to developing thyroid disease, which sometimes precedes cancers.

The longer a firefighter is exposed to this fire suppressant, the higher their risk of developing thyroid cancer is.

Furthermore, PFOA, another toxic chemical from this group, was found to inhibit the accumulation of iodine by thyroid follicular cells in vitro, which is a major risk factor for thyroid cancer. If you have been working as a firefighter, used AFFF regularly, and worry that you might have developed thyroid cancer, the following are the symptoms you should look out for and for which you should seek medical attention immediately:

• a lump that can be felt through the skin on the neck
• changes to the voice, including hoarseness
• difficulty swallowing
• swollen lymph nodes in the neck

PFAS can have several detrimental effects on endocrine function, including the thyroid. In animal studies, PFAS were found to cause hypertrophy and hyperplasia of thyroid follicular cells in rats and showed a strong association with low total and free thyroxine concentrations. If these changes occur in the thyroid gland, the risk of developing cancer increases. If you are a civilian or military firefighter who used AFFF on the job and now struggle with thyroid cancer, we advise you to contact our AFFF attorneys, as you might be entitled to financial compensation.

How PFAS from AFFF causes thyroid cancer

Scientific research has identified several mechanisms through which PFAS exposure leads to thyroid cancer development. The International Agency for Research on Cancer classifies PFOA as carcinogenic to humans and PFOS as possibly carcinogenic, based on evidence including mechanistic data.

PFAS are recognized as endocrine-disrupting chemicals, meaning they interfere with hormone systems in ways that promote cancer development:

• PFAS disrupt thyroid hormone production by interfering with enzymes like thyroid peroxidase, which affects thyroxine (T4) and triiodothyronine (T3) levels
• PFOA and PFOS accumulate in thyroid cells, and a cytotoxic effect was noted following exposure to extremely high concentrations
• PFOS and PFOA inhibit the activity of thyroperoxidase, the enzyme involved in thyroid hormone synthesis
• Chronic perturbation of thyroid hormone pathways promotes abnormal cell proliferation, a hallmark of cancer, especially in a tissue reliant on precise hormonal signaling, like the thyroid

PFAS-induced hormonal dysregulation contributes to carcinogenic processes in hormone-sensitive tissues by disrupting gene expression within thyroid tissue, altering signaling pathways involved in cell growth and apoptosis (programmed cell death), and influencing other endocrine axes such as estrogen that interplay with thyroid biology.

PFAS like PFOS and PFOA remain in the body for years, with half-lives of several years, amplifying the opportunity for long-term biological impact. Chronic internal exposure promotes cancer development through multiple pathways:

• Promoting oxidative stress and inflammation
• Triggering epigenetic changes that alter gene regulation without DNA mutation
• Enhancing cellular environments conducive to tumor development

Studies conducted before 2017 on the interference of PFAS with thyroid function in humans mostly found a higher occurrence of hypothyroidism due to exposure to PFOA, both in the general population and in exposed communities. In 2018, researchers studying the Korean adult general population found a positive correlation between PFAS and abnormal thyroid hormone levels, confirming the results of the previous studies. PFAS exposure has been associated with changes in thyroid hormone levels and indicators of thyroid dysfunction in population studies, and these disruptions create conditions that can lead to cancer development over time.

Why military firefighters face elevated thyroid cancer risk

The U.S. Navy and 3M developed AFFF in 1966 specifically for military use. Since then, military firefighters have depended on this foam to combat jet fuel and petroleum fires at bases across the country. This regular use has led to significant exposure pathways that raise thyroid cancer risk for service members who worked in firefighting roles.

Military bases used AFFF most intensively in three key locations:

• Firefighting training facilities where new firefighters ran through foam application exercises over and over, saturating the soil with PFAS each time
• Active crash sites where aircraft emergencies required immediate foam deployment to control volatile fuel fires
• Maintenance hangars with installed AFFF systems that released foam during routine checks, accidental discharges, and emergency preparedness drills

The military has declared it will phase out PFAS containing foams, but this transition arrives too late for the thousands of military firefighters who spent entire careers handling these toxic substances. Civilian firefighters encounter comparable risks, though generally with less frequent exposure than their military counterparts. Both groups experience thyroid cancer rates higher than what's seen in the general population.

Firefighters absorb PFAS from their own protective gear as well. Their turnout equipment contains PFAS for heat resistance, so they're wearing a chemical exposure source directly against their skin throughout every shift and training exercise.

Misdiagnosis challenges for firefighters with thyroid cancer

Firefighters seeking medical care for thyroid cancer symptoms often receive incorrect initial diagnoses. The misdiagnosis rate runs higher among people exposed to toxic chemicals, making it necessary for firefighters to obtain second and even third medical opinions before pursuing legal claims.

Thyroid cancer symptoms can look like other conditions, causing doctors to diagnose the wrong illness. Common misdiagnoses that firefighters receive instead of thyroid cancer include:

• Heart disease
• Sleep disorders
• Liver disease
• Vitamin deficiencies
• Kidney disease
• Blood disorders
• Depression
• Neurologic disorders

Research indicates that 40% to 60% of people with thyroid disease remain unaware of their condition. Even skilled physicians can overlook thyroid cancer, particularly in early stages when symptoms stay mild or resemble other health issues.

Obtaining an accurate diagnosis matters both for treatment and legal eligibility. Firefighters need complete testing, including blood work to evaluate thyroid hormone levels, imaging studies like ultrasound or CT scans to identify thyroid abnormalities, and biopsy results to confirm cancer when suspicious nodules are found. Only a confirmed thyroid cancer diagnosis makes you eligible for AFFF exposure claims.

If your doctor diagnosed you with one of the conditions listed above but you have a history of AFFF exposure, consult another medical specialist for a thorough thyroid evaluation.