PFAS Exposure & Cancer

Per- and polyfluoroalkyl substances (PFAS) is a class of compounds that includes two industrial solvents: perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS). PFAS chemicals have been used in consumer products worldwide since the 1950s.

Because the carbon-fluoride bond in the chemicals is among the strongest chemical bonds in nature, these chemicals do not break down in the environment. They are thus among the substances known as “forever chemicals.”¹

What Products Contain PFAS?

PFAS chemicals appear in:

• Non-stick cookware
• Stain-resistant fabrics
• Firefighting foams

“How does PFAS cause cancer?” remains a question under investigation. One exploratory study of PFOA and breast cancer, however, suggests that exposure to the chemical may increase the levels of certain cellular messengers while decreasing the levels of compounds that protect cells from becoming cancerous.⁴

In particular, the study focuses on how PFAS chemicals interact with hormone-sensitive cells. Further study may help to explain PFAS chemicals’ effects on other hormone-sensitive cells, such as those in the testicles, liver, and pancreas.

Medical Consensus on PFAS

Studies of PFAS have found the substances to be “linked to many harmful health effects, including cancer,” and thus to rank as a “serious global health threat.”²

Medical studies of PFAS chemicals indicate that exposure to one or more chemicals in the class is connected to an increased risk of cancer. A medical panel convened in a PFOA-related class-action lawsuit determined that the most likely outcomes of PFOA exposure included:

• Kidney cancer
• Testicular cancer
• Ulcerative colitis
• Thyroid disease
• Hypercholesterolemia
• Pregnancy-induced hypertension³

These findings are consistent with multiple independent medical studies connecting PFOA exposure to the listed medical conditions.

AFFFs are used to fight liquid fuel fires. They work by forming a barrier over the liquid fuel, containing flammable vapors to prevent the spread of the fire and extinguish it.⁷

The US Fire Administration (USFA) states that while foams that contain PFAS are more effective at extinguishing liquid-fuel fires, they are also linked to “harmful effects on humans and animals” and do not degrade in the environment.

In January 2023, the Department of Defense issued new guidelines for firefighting foams used on military bases. These foams must effectively fight liquid-fuel fires without containing PFAS chemicals.⁸

Firefighting is associated with higher risks of several types of cancer, as well as higher cancer risks from non-PFAS sources like smoke.⁶

Determining whether exposure to AFFFs is the primary cause of a firefighter’s cancer requires careful attention on a case-by-case basis and poses an ongoing medical-legal challenge.

Specific Risks Firefighters Face

PFAS chemicals have various uses. One is as an ingredient in aqueous film-forming foams (AFFFs), which are used in firefighting. Because firefighters come into contact with PFAS as part of their job, they may face higher risks of forming PFAS-related cancers than members of the general population.

The risk is heightened by the fact that many firefighters aren’t aware of the potentially dangerous outcomes of AFFFs exposure. One study found that over 80 percent of surveyed Florida fire departments used AFFFs - and that most of the firefighters surveyed did not know PFAS chemicals are linked to cancer.⁵

In one study of female firefighters in San Francisco, researchers found elevated carcinogen levels in the firefighters’ blood samples - an early warning sign of a heightened risk of developing future cancers.⁶

As awareness of PFAS and its effects expands, so do lawsuits and legislative actions intended to address PFAS contamination and exposure.

Lawsuits

• November 2023: The city of Wausau, Wisconsin files a complaint against 15 PFAS manufacturers and 61 insurers, alleging the city’s water supply has been contaminated by PFAS from the manufacturers.⁹ The lawsuit follows filings by other Wisconsin localities, including Eau Claire, Campbell, and Rhinelander, according to Wisconsin Public Radio.¹⁰
• August 2023: Manufacturer DuPont agrees to pay $1.185 billion. The settlements affected the trajectory of the PFAS MDL filed in South Carolina.¹¹
• June 2023: PFAS manufacturer 3M agrees to pay at least $10.3 billion to settle PFAS water contamination lawsuits.¹²
• December 2018: Multidistrict litigation commenced in the District of South Carolina on a transfer order from the Judicial Panel on Multidistrict Litigation. The cases generally alleged that AFFFs containing PFAS chemicals contaminated groundwater on or near various military bases, airports, and industrial sites, causing injuries to plaintiffs. The cases were consolidated as MDL 2873.¹³

Legislation

Legislative steps related to PFAS include:

• November 2023: The EPA announces changes to TRI reporting requirements for PFAS chemicals and to supplier notifications for chemicals of special concern. ¹⁴
• October 2023: The EPA proposes adding PFAS chemicals to the list of substances that qualify an area for Superfund designation under CERCLA. ¹⁵
• February 2020: The EPA announces a proposed decision to regulate levels of PFOA and PFOS in drinking water.¹⁶