PFAS in animal by-products in Lanzhou, China, and health risk assessment

Purpose: Per- and polyfluoroalkyl substances (PFAS) comprise a class of man-made compounds widely utilized in manufacturing everyday consumer products. Experimental studies indicate that PFAS may interfere with iron regulation by hindering absorption or inducing oxidative stress. Nonetheless, epidemiological studies examining the association between PFAS exposure and a broad spectrum of iron-related biomarkers remain scarce. Approach and Results: In this study, data from the 2013–2018 National Health and Nutrition Examination Survey (NHANES) were analyzed, which included 5050 adults aged 18 and older. The relationships between six PFAS compounds, oral iron intake, and a comprehensive set of markers of iron homeostasis, including serum iron, unsaturated iron-binding capacity (UIBC), total iron-binding capacity (TIBC), transferrin saturation, ferritin, and transferrin receptor levels, were examined. Our findings revealed a negative association between both individual and total PFAS (sum of six PFAS) levels and oral iron intake. Additionally, serum iron and transferrin saturation levels exhibited significant positive correlations with all PFAS compounds, whereas ferritin was positively correlated with all PFAS compounds except n-perfluorooctanoic acid (n-PFOA). UIBC and transferrin receptor showed significant negative correlations with all PFAS compounds, while TIBC was significantly negatively correlated with n-perfluorooctane sulfonic acid (n-PFOS), perfluoromethylheptane sulfonic acid isomers (sm-PFOS), perfluorohexane sulfonic acid (PFHxS), and the total PFAS. Conclusions: Higher PFAS exposure was associated with altered iron status biomarkers While this cross-sectional study cannot establish causality, the observed associations raise the possibility that PFAS exposure may influence iron absorption. These findings emphasize the need for additional research into the potential impact of PFAS exposure on iron homeostasis.

Dietary intake, especially foods of animal-origin, is an important source of per- and polyfluoroalkyl substances (PFAS) exposure to the general population. However, the distribution of legacy and emerging PFAS in different food categories is unclear, as well as their potential health risk for children. To investigate dietary sources of PFAS and evaluate the risk for 7-year-old children in Laizhou Wan, a region with high PFAS exposure in Shandong, China. We sampled participants from the Laizhou Wan Birth Cohort study. We administered a dietary questionnaire to the parents of 7-year-old children and measured PFAS compounds in the serum of the children (n = 154) and meat and seafood samples (n = 45). We calculated the Mann-Whitney U test to compare serum PFAS levels between children who frequently consumed a specific type of marine fish or shrimp/shellfish and those who did not. Children's dietary PFAS intake was calculated through multiplying food consumption and PFAS concentrations, and health risks were assessed by comparing the intake of PFAS with health-based guideline values. In seafood, perfluorooctanic acid (PFOA) (0.52 ng/g wet weight (ww)), perfluoro-6-methylheptanesulfonic acid (iso-PFOS) (0.02 ng/g ww), and 6:2 chlorinated polyfluoroethersulfonic acid (0.06 ng/g ww) had the highest median concentrations among 10 linear PFAS, 8 branched isomers of PFOA and perfluorooctanesulfonic acid (PFOS), and 3 alternatives, respectively. Particularly, PFOA levels (median, 87.80 ng/g) in Zoarces slongatus (one type of marine fish), were approximately 10-100 times of those in other seafood species. Children who frequently consumed Zoarces slongatus had higher serum PFAS levels, especially PFOA, than those who did not. Seafood intake accounted for more than 80% of the total estimated daily intake of PFAS. The dietary estimated weekly intake values of four PFAS (PFOA, PFOS, perfluorononanoic acid, and perfluorohexanesulfonic acid) for children (7.4 ng/kg of body weight (bw)/week) exceeded the tolerable weekly intake (4.4 ng/kg bw/week) as recommended by the European Food Safety Authority. Seafood was widely contaminated by both legacy PFAS and their alternatives in Laizhou Wan area. Intake of seafood, especially Zoarces slongatus, may contribute greatly to PFAS exposure in 7-year-old children. Avoiding intake of high PFAS polluted seafood may be an important strategy to protect local children. https://doi.org/10.1289/EHP15157.

Per- and polyfluoroalkyl substances (PFAS) have become a significant global environmental issue due to their widespread presence in the environment and their potential to have detrimental effects on human health. This study provides a comprehensive overview of PFAS, including the physicochemical properties of different PFAS compounds and their sources in various environments. Human biomonitoring (HBM) studies are also examined to assess the extent of exposure to and accumulation of these contaminants in human tissues and biological media. HBM of PFAS typically involves analyzing blood (serum and plasma), as well as human milk and urine. Studies have frequently detected PFAS in human serum, with varying concentrations. Serum PFOA and PFOS levels differ significantly across regions, with China reporting concentrations as high as 191 ng/mL for PFOA and 14 ng/mL for PFOS in some populations, while African countries report much lower levels, with medians of 0.12 ng/mL for PFOA and 0.53 ng/mL for PFOS. These regional disparities highlight variations in PFAS exposure and usage. Human milk is also a valuable matrix for assessing human exposure to PFAS, with studies showing that PFOA (Perfluorooctanoic Acid) and PFOS (Perfluorooctane Sulfonate) remain the two predominant PFAS in human milk. Furthermore, this review assesses the health effects of PFAS exposure on vulnerable populations, including fetuses, infants, children, and adolescents. Results identified that PFAS are environmental contributors to adverse fetal growth and birth outcomes. Exposure during pregnancy and early childhood is associated with various adverse outcomes, including Low birth weight (LBW), fetal growth restriction, and developmental problems. Some studies have also found links between exposure to PFAS and cognitive and behavioral development in children, including attention-deficit hyperactivity disorder (ADHD), lower IQ, and anxiety. While scientific evidence is not yet definitive, further research is required to determine the full extent of the health impacts of PFAS exposure during these sensitive developmental periods. Research has established a link between PFAS exposure and various health risks in children and adolescents, including ADHD, behavioral difficulties, precocious puberty, kidney disease, thyroid hormone disruption, and changes in reproductive hormone. Therefore, continuous actions should be conducted to mitigate PFAS contamination and minimize its impact on human health. This comprehensive review highlights the intricate nature of PFAS contamination and emphasizes the necessity for ongoing research to inform risk assessment, policy development, and public health interventions. The insights garnered from this review will be invaluable to researchers, policymakers, and regulatory agencies seeking to grasp the extent of PFAS contamination and its consequences for environmental sustainability and human health.

The sources and bioaccumulation of per- and polyfluoroalkyl substances in animal-derived foods and the potential risk of dietary intake

The occurrence and distributions of per- and polyfluoroalkyl substances (PFAS) in groundwater after a PFAS leakage incident in 2018.

Per- and polyfluoroalkyl substances (PFAS) are extensively used in urban environments and are, thus, found in urban stormwater. However, the relevance of stormwater as a pathway for PFAS to urban streams is largely unknown. This study evaluated the impact of urban stormwater runoff on PFAS concentrations and spatial distribution in three urban streams affected by stormwater discharges from separate sewer systems. River water was sampled during dry (DW) and wet weather (WW) upstream, immediately downstream, and further downstream of three urbanized areas with separate sewer systems and with and without point sources (i.e. waste water treatment plant, airports). Water samples were analyzed for 34 targeted PFAS compounds and sediment samples for 35 targeted PFAS and 30 PFAS compounds using a total oxidizable precursor assay. The sum of the quantified PFAS concentrations ranged from the reporting limit (RL) to 84.7 ng/L during DW and increased as the streams were affected by WW discharges (0.87 to 102.3 ng/L). The highest PFAS concentrations were found downstream of urban areas and/or point sources (i.e. airports) during WW, indicating a clear contribution from stormwater discharges. A consistent PFAS contribution from the WWTP was observed under both DW and WW conditions. During WW events, concentrations of perfluorooctanesulfonic acid (PFOS) and total PFAS (PFOA equivalents) exceeded the annual average environmental quality standards, which are an established limit of 0.65 ng/L for PFOS and a proposed limit of 4.4 ng/L for total PFAS. Notably, except for the legacy PFAS, PFOS and perfluorooctanoic acid (PFOA), the most frequently quantified PFAS during DW were short-chain. For WW, long-chain perfluorocarboxylic acids (PFCAs) and a precursor, 6:2 Fluorotelomer sulfonic acid (6:2 FTS), were more frequently quantified, suggesting stormwater is a source of these longer-chain and particle-associated PFAS. The detection of unregulated fluorotelomer sulfonates (FTSs) such as 6:2 and 8:2 FTS during WW suggests a need for regulatory action, as these compounds can degrade into more stable PFAS. In sediment, higher concentrations, and a greater variety of PFAS were found at sites with known point sources i.e. airports. Long-chain PFCAs (C7-C13), perfluoroalkyl sulfonates (PFSAs) (C6), and precursors (i.e. N-Ethyl perfluorooctane sulfonamidoacetic acid), were more prevalent in sediments than in the water. Notably, PFOS concentrations in sediment exceeded the lowest Predicted No-Effect Concentration (PNEC) across sites, posing a potential long-term environmental risk, though current PNECs for other PFAS may underestimate such risks. The findings of the study highlight urban stormwater as a source of PFAS to urban streams indicating the need to minimize PFAS sources in the urban environment and to effectively treat stormwater to protect receiving water bodies.

The current article reviews the state of art of the perfluoroalkyl and polyfluoroalkyl substances (PFASs) compounds and provides an overview of PFASs occurrence in the environment, wildlife, and humans. This study reviews the issues concerning PFASs exposure and potential risks generated with a focus on PFAS occurrence and transformation in various media, discusses their physicochemical characterization and treatment technologies, before discussing the potential human exposure routes. The various toxicological impacts to human health are also discussed. The article pays particular attention to the complexity and challenging issue of regulating PFAS compounds due to the arising uncertainty and lack of epidemiological evidence encountered. The variation in PFAS regulatory values across the globe can be easily addressed due to the influence of multiple scientific, technical, and social factors. The varied toxicology and the insufficient definition of PFAS exposure rate are among the main factors contributing to this discrepancy. The lack of proven standard approaches for examining PFAS in surface water, groundwater, wastewater, or solids adds more technical complexity. Although it is agreed that PFASs pose potential health risks in various media, the link between the extent of PFAS exposure and the significance of PFAS risk remain among the evolving research areas. There is a growing need to address the correlation between the frequency and the likelihood of human exposure to PFAS and the possible health risks encountered. Although USEPA (United States Environmental Protection Agency) recommends the 70 ng/L lifetime health advisory in drinking water for both perfluorooctane sulfonate (PFO) perfluorooctanoic acid (PFOA), which is similar to the Australian regulations, the German Ministry of Health proposed a health-based guidance of maximum of 300 ng/L for the combination of PFOA and PFOS. Moreover, there are significant discrepancies among the US states where the water guideline levels for the different states ranged from 13 to 1000 ng L−1 for PFOA and/or PFOS. The current review highlighted the significance of the future research required to fill in the knowledge gap in PFAS toxicology and to better understand this through real field data and long-term monitoring programs.

Incidence of per- and polyfluoroalkyl substances (PFAS) in private drinking water supplies in Southwest Virginia, USA

Per- and polyfluoroalkyl substances (PFAS) involve multiple per- and polyfluorinated compounds that are widely used globally. Legacy PFAS, including PFOA, PFOS, and PFHxS, were manufactured before 2000 in various industrialized nations, then gradually phased out in accordance with the Stockholm Convention. Due to the substantial accumulation of these legacy PFAS compounds, their concentrations in drinking water are regulated in some countries. This review first summarizes the historical background of PFAS, followed by a description of their chemical properties. The clinical manifestations of legacy PFAS in humans, such as dyslipidemia, attenuated immune function, and chronic kidney disorders, are also summarized. Emerging PFAS involve Gen-X and F-53B as well as numerous newly developed chemicals with their associated precursors/metabolites, including volatile PFAS. Research on these emerging PFAS compounds in the environment continues to grow, building a substantial body of evidence about their effects. The chemical structure of emerging PFAS shows a wide variety: they could contain ether, ester, sulfoneamide, and other halogen atoms rather than fluorine. Volatile PFAS involve the fluorotelomer 6:2 FTOH and other short-chain PFAS compounds, which are best measured by GC-MS. This review also briefly summarizes the assay for total oxidizable precursors of PFAS, an LC-MS-based assay for an emerging assay that will be used for a quantitative estimation of total PFAS, including emerging PFAS.

BackgroundNear Antwerp a 3M factory has been active since 1971 emitting PFAS, mainly PFOS, in the local environment. Production of C8 compounds was stopped in 2002, production of other PFAS continued until 2024. This study aimed to examine the association between internal PFAS concentrations and thyroid hormones, sexual hormones, and pubertal development in adolescents living in the neighborhood of the factory.MethodsWe measured PFAS in serum of 146 female and 139 male adolescents. For males sex hormones (LH, testosterone, estradiol, progesterone, inhibin B, FSH) and SHBG were measured in serum. For males and females we assessed serum thyroid hormone levels (TSH, T3, T4 and T3/T4) and pubertal development parameters self-assessed through a standardized questionnaire. Associations between PFAS concentrations and effect biomarkers/health effects were assessed through Generalized Estimating Equations (GEE), using linear models for continuous outcomes, logistic models for binary outcomes, and proportional odds models for ordinal outcomes.ResultsFor males LH, total and bioavailable testosterone showed significant negative associations with PFHxS and PFOA. LH and bioavailable testosterone also showed significant negative associations with other PFAS compounds. SHBG showed significant positive associations with PFDA, PFNA, PFHxS, PFOS and the sum of the linear forms of PFOS, PFOA, PFNA and PFHxS. Males’ length and growth spurt showed significant negative associations with PFOS, PFOA and PFAS sum parameters and length and growth spurt separately also with other PFAS compounds. For females growth spurt showed significant negative association with PFOA and a significant positive association with PFOS(branched). For both males and females body hair development showed significant negative associations with PFHxS, and, for males and females separately also with other PFAS compounds. For females, breast development showed significant negative associations with PFOA, pubertal development scale showed significant negative associations with PFOA, PFHxS, PFOS(linear) and the sum of 4 PFAS. For males, TSH showed a significant negative association with PFDA and FT3 showed significant positive associations with PFOA, PFOA and PFNA. For females, FT3 showed a significant negative association with PFOS(branched).ConclusionWe observed significant, consistent and biologically relevant associations of PFAS serum concentrations with sex hormone and SHBG levels in male adolescents. Moreover, a significant delay in physiological processes occurring in puberty was observed in females and males. Associations with thyroid hormones differed significantly by sex

SUMMARY Regulatory authorities in the field of environmental health often grapple with decision-making in the face of scientific uncertainty and rapidly emerging data. The identification of per- and polyfluoroalkyl substances (PFAS) contamination in drinking water sources in Israel, and the need for rapid decision-making on PFAS drinking water standards, is one such example. The Water Authority, which is responsible for management of the water sector in Israel, first discovered PFAS contamination in groundwater in 2019. The Ministry of Health (MOH), which is responsible for drinking water quality, began measuring PFAS compounds in 2020. As of the end of 2024, the MOH has measured nine PFAS compounds in over 375 drinking water wells, 14.7% of which have at least one detected PFAS compound. This manuscript reviews four considerations taken into account in the decision on guideline values for PFAS: toxicological threshold, consideration of current worldwide regulatory standards, practical achievability, and analytical capacity. Based on these considerations, the MOH adopted Health Canada’s 2018 maximum acceptable concentrations in drinking water for perfluorooctanoate (PFOA) and perfluorooctane sulfonic acid (PFOS) as an interim guideline value. Subsequently, the MOH decided to adopt the EU Drinking Water Directive standards on PFAS, which include 20 PFAS compounds, and which will enter into force in 2026. To date, drinking water supply has been discontinued from four wells, and another 10 drinking water wells will be discontinued or will require treatment once the stricter standard enters force. Quarterly or annual monitoring for tens of wells is required, depending on measured PFAS concentrations. In addition to ongoing monitoring of PFAS in drinking water wells, the MOH is conducting a human biomonitoring (HBM) study to measure PFAS in blood in an adult population and is involved in work developing HBM guideline values, as part of the Partnership for Chemical Risk Assessment (PARC).

BackgroundPer- and polyfluoroalkyl substances (PFAS), particularly perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), are synthetic chemicals known for their widespread use and environmental persistence. These compounds have been increasingly linked to hepatotoxicity and the development of hepatocellular carcinoma (HCC). However, the molecular mechanisms by which PFAS contribute to HCC remain underexplored.MethodsThis study employs a multi-omics approach that combines network toxicology, integrated machine learning, single-cell RNA sequencing, spatial transcriptomics, experimental validation, and molecular docking simulations to uncover the mechanisms through which PFAS exposure drives HCC. We analyzed publicly available transcriptomic data from several HCC cohorts and used differential gene expression analysis to identify targets associated with both PFAS exposure and HCC. We constructed a protein–protein interaction (PPI) network and a survival risk model, the PFAS-related HCC signature (PFASRHSig), based on integrated machine learning to identify prognostic biomarkers, with the goal of identifying core targets of PFAS in HCC progression and prognosis. RT-qPCR and immunohistochemical (IHC) staining were used to validate the expression levels of the targets in both tumor and normal tissues. Molecular docking simulations were conducted to assess the binding affinities between PFAS compounds and selected target proteins.ResultsFunctional enrichment studies revealed that PFAS targets were associated with metabolic signaling pathways, which are actively involved in lipid, glucose, drug metabolism, etc. Through integrated machine learning and PPI network analysis, we identified six genes, APOA1, ESR1, IGF1, PPARGC1A, SERPINE1, and PON1, that serve as core targets of PFAS in both HCC progression and prognosis. These targets were further validated via bulk RNA-seq, single-cell RNA-seq, and spatial transcriptomics, which revealed differential expression patterns across various cell types in the HCC tumor microenvironment. The results of RT-qPCR and IHC staining were consistent with the in silico findings. Molecular docking simulations revealed strong binding affinities between PFAS compounds and these core targets, supporting their potential roles in PFAS-induced hepatocarcinogenesis.ConclusionsOur study highlights key molecular targets and pathways involved in PFAS-induced liver carcinogenesis and proposes a robust survival risk model (PFASRHSig) for HCC. These findings provide new insights into PFAS toxicity mechanisms and offer potential therapeutic targets for mitigating the health risks associated with PFAS exposure. Collectively, our findings help in advancing clinical applications by providing insights into disease mechanisms and potential therapeutic interventions.

Maternal exposure to per- and polyfluoroalkyl substances and epitope level antibody response to vaccines against measles and rubella in children from the Boston birth cohort.

Perfluoroalkyl and polyfluoroalkyl substances contamination in dairy: A global perspective.

Levels of per- and polyfluoroalkyl substances (PFAS) in foodstuffs: a review of dietary exposure, health risks, and regulatory challenges.