







Abstract. Exposure to poly- and perfluoroalkyl substances (PFASs) has been linked to many negative health impacts in humans and wildlife. Unlike neutral hy
PFAS Exposure Pathways for Humans and Wildlife: A Synthesis of Current Knowledge and Key Gaps in Understanding
Abstract. We synthesize current understanding of the magnitudes and methods for assessing human and wildlife exposures to poly‐ and perfluoroalkyl substanc

Legacy and Novel Per- and Polyfluoroalkyl Substances in Juvenile Seabirds from the U.S. Atlantic Coast
Abstract. Per- and polyfluoroalkyl substances (PFAS) are anthropogenic, globally distributed chemicals. Legacy PFAS, including perfluorooctane sulfonate (P

A review of the pathways of human exposure to poly- and perfluoroalkyl substances (PFASs) and present understanding of health effects
Here, we review present understanding of sources and trends in human exposure to poly- and perfluoroalkyl substances (PFASs) and epidemiologic evidence for impacts on cancer, immune function, metabolic outcomes, and neurodevelopment. More than 4000 PFASs have been manufactured by humans and hundreds have been detected in environmental samples. Direct exposures due to use in products can be quickly phased out by shifts in chemical production but exposures driven by PFAS accumulation in the ocean and marine food chains and contamination of groundwater persist over long timescales. Serum concentrations of legacy PFASs in humans are declining globally but total exposures to newer PFASs and precursor compounds have not been well characterized. Human exposures to legacy PFASs from seafood and drinking water are stable or increasing in many regions, suggesting observed declines reflect phase-outs in legacy PFAS use in consumer products. Many regions globally are continuing to discover PFAS contaminated sites from aqueous film forming foam (AFFF) use, particularly next to airports and military bases. Exposures from food packaging and indoor environments are uncertain due to a rapidly changing chemical landscape where legacy PFASs have been replaced by diverse precursors and custom molecules that are difficult to detect. Multiple studies find significant associations between PFAS exposure and adverse immune outcomes in children. Dyslipidemia is the strongest metabolic outcome associated with PFAS exposure. Evidence for cancer is limited to manufacturing locations with extremely high exposures and insufficient data are available to characterize impacts of PFAS exposures on neurodevelopment. Preliminary evidence suggests significant health effects associated with exposures to emerging PFASs. Lessons learned from legacy PFASs indicate that limited data should not be used as a justification to delay risk mitigation actions for replacement PFASs.

Unbound Fractions of PFAS in Human and Rodent Tissues: Rat Liver a Suitable Proxy for Evaluating Emerging PFAS?
Abstract. Adverse health effects associated with exposures to perfluoroalkyl and polyfluoroalkyl substances (PFAS) are a concern for public health and are

PFAS and Precursor Bioaccumulation in Freshwater Recreational Fish: Implications for Fish Advisories
Abstract. Per- and polyfluoroalkyl substances (PFAS) are a diverse class of fluorinated anthropogenic chemicals that include perfluoroalkyl acids (PFAA), w

Liver and Intestinal Fatty Acid Binding Proteins Are Not Critical for Perfluorooctanesulfonate (PFOS) Tissue Distribution and Elimination in Mice
Abstract. Perfluorooctanesulfonate (PFOS) is a persistent environmental pollutant in the per- and polyfluoroalkyl substances (PFAS) class, known to accumul

Shifting Global Exposures to Poly- and Perfluoroalkyl Substances (PFASs) Evident in Longitudinal Birth Cohorts from a Seafood-Consuming Population
Abstract. Rapid declines in legacy poly- and perfluoroalkyl substances (PFASs) have been reported in human populations globally following changes in produc

Whale Baleen To Monitor Per- and Polyfluoroalkyl Substances (PFAS) in Marine Environments
Abstract. Per- and polyfluoroalkyl substances (PFAS) comprise >10 000 synthetic compounds that are globally distributed and highly persistent but remain

Passive Sampler Derived Profiles and Mass Flows of Perfluorinated Alkyl Substances (PFASs) across the Fram Strait in the North Atlantic
Abstract. Per- and polyfluorinated alkyl substances (PFAS) are a family of pollutants of high concern due to their ubiquity and negative human health impac

Large declines in organofluorine contamination indicated by subarctic marine mammal tissues
The ocean is thought to be the terminal sink for per- and polyfluoroalkyl substances (PFAS), persistent organofluorine chemicals used widely in modern commerce for decades. Industry and stewardship programs phased out the most abundantly produced legacy PFAS in the early 2000s due to toxicity concerns. However, they have since been replaced by shorter carbon chain and “novel” chemistries, and past work hypothesized likely increases in these replacement PFAS that were not previously quantifiable. To address this gap, we measured bulk extractable organofluorine (EOF) in archived liver and muscle tissues from pelagic Subarctic pilot whales over the last several decades. Results show EOF concentrations peaked in 2011 and declined by over 60% by 2023. Among a broad suite of targeted and suspect PFAS measured using high-resolution mass spectrometry, only one was consistently increasing through 2023. Tissue concentrations of four main legacy PFAS that accounted for over 75% of EOF were all decreasing by 2023. The timing of peak concentrations depended primarily on whether they were transported to the subarctic by ocean circulation or atmospheric deposition, with the latter declining much faster. Oceanic transport and bioaccumulation modeling suggests that decadal-scale lags between production and food web bioaccumulation are primarily driven by marine transport processes. Large declines in tissue concentrations in this study reinforce the effectiveness of phase-outs in chemical production. However, other work showing stable or increasing EOF in human serum suggests many emerging PFAS with more neutral physicochemical properties may be preferentially accumulating in terrestrial and nearshore environments compared to legacy PFAS.

How Do We Measure Poly- and Perfluoroalkyl Substances (PFASs) at the Surface of Consumer Products?
Abstract. Exposures to poly- and perfluoroalkyl substances (PFASs) have been linked to metabolic disruption, immunotoxicity, and cancer in humans. PFASs ar

Can profiles of poly- and Perfluoroalkyl substances (PFASs) in human serum provide information on major exposure sources?
Humans are exposed to poly- and perfluoroalkyl substances (PFASs) from diverse sources and this has been associated with negative health impacts. Advances in analytical methods have enabled routine detection of more than 15 PFASs in human sera, allowing better profiling of PFAS exposures. The composition of PFASs in human sera reflects the complexity of exposure sources but source identification can be confounded by differences in toxicokinetics affecting uptake, distribution, and elimination. Common PFASs, such as perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS) and their precursors are ubiquitous in multiple exposure sources. However, their composition varies among sources, which may impact associated adverse health effects.

Understanding Mechanisms of PFAS Absorption, Distribution, and Elimination Using a Physiologically Based Toxicokinetic Model
Abstract. Exposures to some per- and polyfluoroalkyl substances (PFAS), including perfluoroalkyl acids (PFAA), have been associated with diverse adverse he

Binding of Per- and Polyfluoroalkyl Substances (PFAS) to Serum Proteins: Implications for Toxicokinetics in Humans
Abstract. Per- and polyfluoroalkyl substances (PFAS) are a diverse class of highly persistent anthropogenic chemicals that are detectable in the serum of m

Bioconcentration of Per- and Polyfluoroalkyl Substances and Precursors in Fathead Minnow Tissues Environmentally Exposed to Aqueous Film-Forming Foam–Contaminated Waters
Abstract Exposure to per- and polyfluoroalkyl substances (PFAS) has been associated with toxicity in wildlife and negative health effects in humans. Decades of fire training activity at Joint Base Cape Cod (MA, USA) incorporated the use of aqueous film-forming foam (AFFF), which resulted in long-term PFAS contamination of sediments, groundwater, and hydrologically connected surface waters. To explore the bioconcentration potential of PFAS in complex environmental mixtures, a mobile laboratory was established to evaluate the bioconcentration of PFAS from AFFF-impacted groundwater by flow-through design. Fathead minnows (n = 24) were exposed to PFAS in groundwater over a 21-day period and tissue-specific PFAS burdens in liver, kidney, and gonad were derived at three different time points. The ∑PFAS concentrations in groundwater increased from approximately 10,000 ng/L at day 1 to 36,000 ng/L at day 21. The relative abundance of PFAS in liver, kidney, and gonad shifted temporally from majority perfluoroalkyl sulfonamides (FASAs) to perfluoroalkyl sulfonates (PFSAs). By day 21, mean ∑PFAS concentrations in tissues displayed a predominance in the order of liver > kidney > gonad. Generally, bioconcentration factors (BCFs) for FASAs, perfluoroalkyl carboxylates (PFCAs), and fluorotelomer sulfonates (FTS) increased with degree of fluorinated carbon chain length, but this was not evident for PFSAs. Perfluorooctane sulfonamide (FOSA) displayed the highest mean BCF (8700 L/kg) in day 21 kidney. Suspect screening results revealed the presence of several perfluoroalkyl sulfinate and FASA compounds present in groundwater and in liver for which pseudo-bioconcentration factors are also reported. The bioconcentration observed for precursor compounds and PFSA derivatives detected suggests alternative pathways for terminal PFAS exposure in aquatic wildlife and humans. Environ Toxicol Chem 2024;43:1795–1806. © 2024 The Author(s). Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. Flow-through dosing experiments utilizing aqueous film-forming foam (AFFF)–contaminated groundwater revealed positive linear correlations between fluorinated carbon chain length and logarithm-transformed bioconcentration factors (BCFs) for perfluoroalkyl sulfonamides identified in fathead minnow (Pimephales promelas) liver via target analysis and suspect screening using high-resolution mass spectrometry. FBSA = perfluorobutane sulfonamide; FHxSA = perfluorohexane sulfonamide; FOSA = perfluorooctane sulfonamide; FPeSA= perfluoropentane sulfonamide; FPrSA = perfluoropropane sulfonamide.

Stability of Per- and Polyfluoroalkyl Substances in Solvents Relevant to Environmental and Toxicological Analysis
Abstract. Per- and polyfluoroalkyl substances (PFASs) are widely used anthropogenic chemicals. For environmental and toxicological analysis, it is importan
