'Safe' forever chemicals may impair brain development

Everyday life is filled with conveniences that many people take for granted. Stain-resistant fabrics, non-stick cookware, and water-repellent items are all around. These products owe their useful properties to a group of synthetic chemicals called per- and polyfluoroalkyl substances, known as PFAS.

While these chemicals make modern life easier, they carry a hidden cost. PFAS are often called “forever chemicals” because they do not break down naturally in the environment.

Once released, they linger in soil, water, and living organisms. Scientists have been studying their effects on human health for decades.

Chemicals and the male brain

One particular chemical, perfluorohexanoic acid (PFHxA), has recently gained attention. Many believed PFHxA, due to its shorter chemical chain, was safer than other PFAS.

However, new research from the Del Monte Institute for Neuroscience at the University of Rochester presents a different story.

In the latest study, scientists uncovered that early life exposure to PFHxA may trigger anxiety-related behaviors and memory issues in male mice.

“Although these effects were mild, finding behavioral effects only in males was reminiscent of the many neurodevelopmental disorders that are male-biased,” said Ania Majewska, PhD, professor of Neuroscience and senior author of the study.

The researchers noted that males are more frequently diagnosed with disorders such as autism and ADHD. “This finding suggests that the male brain might be more vulnerable to environmental insults during neurodevelopment,” Majewska added.

Chemical exposure and brain development

The research team exposed pregnant and nursing mice to PFHxA through mealworm treats. The chemical affected their offspring, particularly the brains of male mice.

The male offspring who received higher doses showed several changes. These included reduced activity, increased anxiety-like behavior, and memory problems. Interestingly, female mice exposed similarly showed no such changes.

“Finding that developmental exposure to PFHxA has long-term behavioral consequences in a mammalian model is concerning when considering short-chain PFAS are thought to be safer alternatives to the legacy PFAS that have been phased-out of production,” said Elizabeth Plunk, first author of the study.

Long-term effects of PFHxA exposure

The team monitored the mice into adulthood. They discovered that male mice exposed to PFHxA retained behavioral changes well beyond their early life stages.

“This work points to the need for more research in short-chain PFAS. To our knowledge, PFHxA has not been evaluated for developmental neurobehavioral toxicity in a rodent model,” said Majewska.

“Future studies should evaluate the cellular and molecular effects of PFHxA, including cell-type specific effects, in regions associated with motor, emotional/fear, and memory domains to elucidate mechanistic underpinnings.”

Regulatory actions and concerns

PFHxA’s shorter chain did not prevent it from persisting in water. The European Union restricted its use in 2024, following earlier restrictions on longer chain PFAS.

Scientists remain concerned because PFHxA can easily spread through water systems, posing a threat to ecosystems and drinking water supplies.

In the United States, the Environmental Protection Agency recently set a national drinking water standard for PFAS. This action aims to reduce exposure for millions of people and prevent potential long-term health risks.

PFAS chemicals are found in food, water, animals, and humans. They resist stains, oil, and water but are linked to various health issues, including developmental problems in babies, certain cancers, immune system disruption, and hormonal imbalances.

The ability of forever chemicals to build up in the body makes their health effects difficult to avoid over time.

Further research is needed

The findings highlight the importance of examining chemicals considered “safe.” They reveal that even short-chain PFAS like PFHxA may pose hidden risks, especially to the developing brain.

According to the study authors, further research is needed. “These preliminary findings indicate that PFHxA exposure may cause long-lasting changes in many behavioral domains in a mammalian model, and more research is needed to expand these evaluations to other cognitive domains,” they wrote.

The research received funding from the National Institutes of Health, the University of Rochester Intellectual and Developmental Disabilities Research Center, and the University of Rochester Environmental Health Sciences Center.

The study is published in the European Journal of Neuroscience.

—–

Like what you read? Subscribe to our newsletter for engaging articles, exclusive content, and the latest updates. 

Check us out on EarthSnap, a free app brought to you by Eric Ralls and Earth.com.

—–