A groundbreaking new study from Boston University School of Public Health (BUSPH) sheds light on the lingering presence of per- and polyfluoroalkyl substances (PFAS) in the American diet and drinking water, underscoring both progress and persistent challenges in exposure reduction. Although concentrations of legacy PFAS—known colloquially as “forever chemicals” due to their extraordinary environmental persistence—appear to have declined in many food items over the last twenty years, the research reveals that drinking water, along with certain dietary sources such as seafood, eggs, and brown rice, remain significant contributors to adult PFAS exposure. This nuanced new understanding demands an urgent reexamination of regulatory strategies targeting both older and emerging chemical variants.
PFAS are a broad class of synthetic chemicals widely utilized in industrial applications and consumer products for their resistance to heat, water, and oil. Over decades, these compounds have seeped into the environment, contaminating soil, water supplies, and food chains. Their resistance to degradation, combined with bioaccumulative properties, has led to widespread human exposure, raising critical concerns about their long-term health impacts. This study, published in the prestigious journal Environmental Science & Technology, takes a novel approach by concurrently evaluating dietary habits and drinking water quality to parse out their relative contributions to PFAS blood burden in a Californian cohort.
The research team analyzed blood samples collected from 700 adults participating in the California Regional Exposure Study between 2018 and 2020, linking PFAS serum concentrations with detailed, self-reported dietary intake and measurements of PFAS contamination in local drinking water supplies. Unlike prior assessments that predominantly relied on European data or isolated food monitoring, this study incorporated U.S.-specific environmental exposure data, reflecting distinct lifestyle and industrial contexts pertinent to American populations. The researchers identified significant associations between legacy PFAS levels in blood and consumption of seafood, eggs, and brown rice, although the breadth of dietary PFAS sources appeared reduced compared to earlier studies.
Importantly, the study confirmed that individuals residing in communities with PFAS detected in their public drinking water had elevated serum PFAS levels relative to those in areas without detectable contamination, even though the measured water contamination levels were generally lower than those documented in heavily polluted regions across the United States. This finding corroborates long-standing concerns about drinking water as a critical pathway for human exposure to PFAS, emphasizing the necessity for vigilant regulatory frameworks and water quality monitoring.
The decline in PFAS exposure from various foods is an encouraging sign that regulatory actions and manufacturing changes are beginning to bear fruit. The Food and Drug Administration (FDA) has actively phased out certain legacy PFAS chemicals from food-contact materials such as grease-resistant papers, which may have contributed to reduced dietary exposure. This trend aligns with industry shifts to reduce reliance on long-chain PFAS compounds due to increasing scientific and public scrutiny. However, the detection of persistent PFAS in select food categories indicates that contamination pathways through agriculture, aquaculture, or food processing remain viable and require continued investigation.
Beyond the legacy chemicals, the study authors stress the urgent need to better understand exposure to newer, replacement PFAS substances, which have entered commercial use as manufacturers phase out older variants. These replacements are chemically diverse, and their toxicity profiles, environmental fate, and human exposure routes remain insufficiently characterized. Indoor sources such as dust, air, and consumer products—including cosmetics—may represent additional significant reservoirs yet to be thoroughly examined.
The health implications of PFAS exposure are profound and well documented. Scientific evidence links these compounds to a range of adverse outcomes, including multiple forms of cancer, immunotoxicity characterized by reduced vaccine efficacy, liver dysfunction, thyroid disruption, and developmental and reproductive harm. Given their omnipresence and persistence, even low-level chronic exposure poses a public health challenge, especially for vulnerable populations such as pregnant women and children.
Environmental epidemiologist Dr. Emily Pennoyer, the study’s lead author and recent BUSPH PhD graduate, notes that the research bridges a critical gap by simultaneously analyzing dietary and drinking water contributions to PFAS body burden under contemporary U.S. conditions. This integrated approach enhances our understanding of exposure dynamics and supports targeted intervention strategies. The study coauthors from the California Department of Public Health reinforce the commitment to ongoing biomonitoring efforts aimed at elucidating chemical exposures across demographically and environmentally diverse populations in the state.
The persistence of PFAS in water supplies demands sustained regulatory vigilance. California’s state agencies have prioritized evaluating and remediating detected PFAS contamination, bolstered by recent federal actions setting enforceable drinking water standards. Experts highlight the necessity of harmonizing these policies with continuing research to capture the evolving landscape of PFAS chemistries and exposure routes. Coordinated efforts among researchers, public health officials, regulators, and industry stakeholders are essential to reduce the human and ecological burden of these hazardous chemicals.
In parallel, public health messaging encourages consumers to limit exposure where possible, including choosing products labeled “fluoro-free” and advocating for greater transparency in product chemical contents. While such individual actions have a role, systemic regulatory reform targeting the entire lifecycle of PFAS—from production and use through disposal—remains paramount to meaningful risk reduction.
This study exemplifies the critical role of contemporary, population-specific research in informing science-based policy making. By delineating current exposure patterns and identifying persistent sources, it lays the groundwork for more effective intervention strategies that encompass both legacy and emerging PFAS compounds. Such contributions are vital to protecting public health amid the complex challenge of managing chemically diverse and environmentally persistent pollutants on a national scale.
Looking forward, the scientific community continues to call for expansive research on PFAS toxicology, environmental fate, human biomonitoring, and exposure mitigation technologies. As regulatory frameworks adapt, integrating novel data streams and advancing analytical techniques will be key to addressing this multifaceted environmental health crisis comprehensively.
Subject of Research: People
Article Title: (Not explicitly stated in the source content)
News Publication Date: 14-May-2025
Web References:
- Environmental Science & Technology Journal Article DOI
- PFAS Action Plan by EPA
- ATSDR Health Effects of PFAS
- FDA PFAS Market Phase-Out
- EPA Drinking Water Regulations
References:
- Pennoyer E., Wu N., Attfield K., Webster T., Heiger-Bernays W. (2025). Environmental Science & Technology. DOI: 10.1021/acs.est.4c11872
Keywords:
Water pollution, Water quality control, Water supply, Pollution, Environmental policy, Environmental health, Public health, Toxins, Food policy, Food safety, Public policy, Environmental sciences
