PFAS Exposure Linked to Weakened Immune Response in Adults, Study Warns

New research has uncovered a troubling link between exposure to PFAS—a class of persistent, human-made chemicals—and weakened immune function in adults. The findings raise serious concerns about the long-term health impacts of these so-called “forever chemicals,” which are widely used in everyday products and environmental settings.

What Are PFAS and Why Are They a Concern?

Per- and polyfluoroalkyl substances (PFAS) are a group of over 4,700 synthetic chemicals designed to resist heat, water, and grease. Commonly found in nonstick cookware, stain-resistant fabrics, food packaging, and firefighting foams, PFAS are notorious for their environmental persistence. Because they do not easily break down, these chemicals accumulate in the human body over time, with some compounds—such as perfluorohexanesulfonic acid (PFHxS)—remaining for nearly a decade.

Study Reveals PFAS Exposure Impairs Antibody Production

A recent study examined individuals previously exposed to PFAS through contaminated drinking water. Researchers discovered that those with higher blood levels of these chemicals produced significantly fewer protective antibodies when their immune systems encountered a new virus. This reduction in antibody production is a critical measure of how effectively the body can respond to and fight infections.

“Antibodies act like tiny soldiers, helping the body recognize and fight off viruses,” says Courtney Carignan, senior author of the study and an environmental health researcher at Michigan State University. “When fewer of these ‘soldiers’ are produced, the immune system may be less effective at fighting infection.”

“These results raise important concerns about how long-term exposure to PFAS reduces the body’s ability to respond to infections, even in adulthood,” she adds.

Who Is Most Affected?

The study found that the impact of PFAS exposure on immune function was most pronounced among:

• Older adults
• Men
• Individuals who are overweight

These groups often have higher levels of PFAS in their bodies, which may exacerbate the immune-suppressing effects of these chemicals.

Real-Life Impact: Families Speak Out

For some families, the consequences of PFAS exposure are already a harsh reality. Tobyn McNaughton, a mother from Belmont, Michigan, whose family was affected by contaminated drinking water, shares her story:

“When you find out your family has been exposed, it changes everything—especially how you think about your children’s health. We’re poisoned people. We learned that some of my son’s childhood vaccines weren’t fully effective due to his compromised immune system, and that’s something no parent expects to face.”

McNaughton connected with Carignan in 2018 after high levels of PFAS were detected in her family’s drinking water. Since then, she has become a vocal clean water advocate with the Great Lakes PFAS Action Network, a group cofounded by her neighbor Sandy Wynn-Stelt that is led by individuals directly impacted by PFAS pollution.

Why This Study Matters

Previous research on PFAS and immune function in adults has yielded mixed results, partly due to the challenges of isolating the effects of prior exposures and existing immunity. However, the COVID-19 pandemic provided a unique opportunity to observe how the immune system responds to a new virus, allowing researchers to more clearly detect the influence of PFAS exposure on antibody production.

“The pandemic provided a rare opportunity to observe how the immune system responds to a new virus, allowing us to more clearly detect how PFAS exposure may influence antibody production and helping resolve long-standing uncertainty about its effects in adults,” Carignan explains. “Our findings make clear that PFAS exposure can affect immune response in adults in addition to the known effects in children.”

Regulatory Response and Ongoing Concerns

The findings arrive as the United States continues to debate and implement new drinking water standards for PFAS. The U.S. Environmental Protection Agency (EPA) recently finalized its first enforceable limits on these chemicals in drinking water, a move aimed at reducing public exposure. However, critics argue that the standards may not go far enough to address the widespread contamination and long-term health risks associated with PFAS.

As the scientific community and policymakers grapple with the implications of these findings, the study underscores the urgent need for further research and stronger regulatory measures to protect public health from the pervasive threat of PFAS exposure.