Per- and polyfluoroalkyl substances (PFAS) represent one of the most challenging environmental health concerns of our time. Used in products ranging from food packaging and firefighting foams to stain- and water-resistant fabrics, these chemicals are widespread in the modern world. While PFAS have made everyday life more convenient, they have also introduced a host of health risks due to their ability to persist in the environment and accumulate in the body.
NIEHS grant recipient Abby Fleisch, M.D. M.P.H., a physician-scientist at MaineHealth, is leading critical research into how PFAS exposure affects health across the lifespan. She has linked early-life PFAS exposure to increased risk of obesity, disrupted fat distribution, and weaker bones in children. Importantly, her studies go beyond identifying health risks. Dr. Fleisch also explores how diet and lifestyle changes may mitigate these harmful effects. Based in Maine, a state that has been deeply affected by PFAS contamination, she combines rigorous research with a passion for empowering communities through education and actionable solutions.
Dr. Fleisch specializes in pediatric environmental health and endocrinology. She serves as an attending physician in pediatric endocrinology and diabetes at Maine Medical Center, a faculty scientist at the MaineHealth Institute for Research, and an associate professor of pediatrics at Tufts University School of Medicine. I recently spoke with Dr. Fleisch to learn more about her work on PFAS, their health implications, and practical steps individuals and communities can take to protect themselves. She also shared what inspired her to pursue a scientific career.
Chemicals accumulate in environment, people
Rick Woychik: For readers who might be new to this topic, can you briefly explain what PFAS are and why they are often called “forever chemicals”?
Abby Fleisch: Sure. PFAS are synthetic chemicals that have been used in consumer and industrial products since the 1950s. Their unique properties, like resistance to heat, water, and oil, make them highly effective in items such as nonstick cookware, grease-resistant food packaging, and water-repellent clothing. Unfortunately, these same properties mean PFAS don’t break down easily in the environment, so they’re often called “forever chemicals.”
In humans, PFAS can accumulate in the bloodstream, with half-lives of three to eight years, depending on the specific compound. Exposure primarily occurs through contaminated water, food, or air, and nearly everyone in the U.S. has detectable levels of PFAS in their blood.
Exposure to these substances is associated with a range of health outcomes, including increased cholesterol levels, decreased vaccine antibody effectiveness, and certain cancers, like kidney cancer. There’s also strong evidence connecting exposure to reduced birth weight. My research has largely focused on metabolic and bone health, looking at how PFAS exposure might increase risk of conditions like obesity, diabetes, and osteoporosis.
Diet, lifestyle changes hold promise
RW: One fascinating aspect of your work is the idea that diet and lifestyle changes may help to mitigate the effects of PFAS. Can you elaborate?
AF: Our team analyzed data and samples from the Diabetes Prevention Program and found that participants with higher PFAS levels at the start of the study had greater weight gain and greater risk for diabetes and high cholesterol over 15 years of follow-up. As part of that study, we discovered something interesting. Those who followed a structured lifestyle intervention that included both dietary counseling and regular physical activity saw reduced effects from PFAS.
Participants in the lifestyle intervention attended regular classes on nutrition and exercise. The program encouraged small, achievable changes like increasing physical activity and incorporating more whole grains, fruits, and vegetables into the diet. These lifestyle modifications appeared to counteract the metabolic risks associated with PFAS.
In another study, through the NIEHS-supported Project Viva, we observed that children with higher PFAS levels had reduced bone accrual from childhood through adolescence. However, teens who engaged in bone-promoting activities like regular exercise and adequate calcium consumption seemed to be able to mitigate these effects. This suggests that early interventions can make a difference, even in the face of significant exposure.
Although evidence is still emerging, there are indications that high-fiber diets and nutrient-dense foods could play a role in supporting the body’s ability to combat metabolic disruptions linked to PFAS. Going forward, my colleagues and I are going to dive deeper and assess what specific diet and lifestyle factors hold the most promise. But based on recent findings, I think it is safe to say that a great starting point, generally, is healthy food and regular exercise.
Addressing contamination in Maine
RW: You currently work in Portland, Maine. Can you talk about how your state is an important setting for studying PFAS?
AF: Maine has experienced significant PFAS contamination from biosolids, which refers to treated sewage that is spread as fertilizer. Use of biosolids isn’t unique to Maine — it has occurred across the U.S. dating back to the 1980s. Our state passed legislation in 2021 requiring the Department of Environmental Protection to conduct PFAS testing in drinking water near areas where the biosolids were spread. Many people learned that they were exposed to high levels of PFAS. In some cases, levels were thousands of times higher than what is typical.
I’ve studied PFAS for more than a decade, primarily at the national level. But when this contamination came to light in my state, the issue became deeply personal. Over the past few years, I’ve started seeing several pediatric patients with high PFAS exposure and their families in my clinic. Building relationships with them and working at MaineHealth, where there’s a strong focus on community-engaged research, positioned me to try to help this community.
Last year, we received NIEHS funding to partner with the central Maine community, which has been significantly affected by PFAS exposure from biosolids. While we know some things about PFAS exposure and potential effects, we don’t know much about exposure specifically from biosolids. Our study focuses on measuring PFAS levels in participants’ blood and drinking water, identifying exposure pathways, and examining the mental health effects of learning that your well water contains elevated levels of PFAS. Specific mental health outcomes that we are assessing are anxiety, perceptions of health risk, and stigma related to exposure.
We hope this research will generate much-needed advice on mitigating exposure and help to build resilience not just in central Maine but also in communities across the U.S. affected by PFAS-contaminated biosolids. We’re just beginning to analyze the data from this work, and I look forward to sharing our findings in the near future.
Supporting communities and patients
RW: It’s admirable that you’re working to bring solutions to people in Maine and elsewhere who have experienced PFAS exposure. As a physician-scientist, how do you advise these patients?
AF: When I see patients in my clinic who have been exposed to elevated levels of PFAS, I follow comprehensive clinical practice guidelines from the National Academies of Sciences, Engineering, and Medicine [NASEM]. The Agency for Toxic Substances and Disease Registry has user-friendly information for clinicians and the public, too, as does an NIEHS-funded project called PFAS Research, Education, and Action for Community Health.
In general, the first step is to reduce exposure. Most patients come to me knowing that they have elevated levels of PFAS in their well water, and this is an important exposure source that can be mitigated by installing a certified water filter. I also talk through with patients whether they might be consuming fish or game from areas known to have elevated PFAS levels, and I review the boundaries of the central Maine “do not fish” and “do not eat” advisories. I also talk through other potential sources of exposure, including breastfeeding for infants and young children and occupation for older teens and young adults.
Next, I talk through the option for PFAS blood testing. The NASEM guidelines provide a clinical monitoring algorithm which recommends additional screening for cholesterol, thyroid function, ulcerative colitis, and testicular and kidney cancer if the PFAS blood level is in the top 9% of the U.S. population. When I talk with patients about health effects, I always frame PFAS as a risk factor — similar to smoking or high cholesterol. I want to support patients in feeling empowered rather than becoming overwhelmed by the risks.
People have many concerns about these substances, which is why I’m honored to both study the health effects of PFAS and use the resulting knowledge to try to improve patient well-being. Communities harmed by contamination need actionable solutions, and the environmental health sciences community can play a major role in helping to deliver on that front.
(Rick Woychik, Ph.D., directs NIEHS and the National Toxicology Program.)
