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Zheng G, Eick SM, Salamova A. Elevated Levels of Ultrashort- and Short-Chain Perfluoroalkyl Acids in US Homes and People. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:15782-15793. [PMID: 37818968 PMCID: PMC10603771 DOI: 10.1021/acs.est.2c06715] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 09/06/2023] [Accepted: 09/07/2023] [Indexed: 10/13/2023]
Abstract
Per- and polyfluoroalkyl substances (PFAS) make up a large group of fluorinated organic compounds extensively used in consumer products and industrial applications. Perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), the two perfluoroalkyl acids (PFAAs) with 8 carbons in their structure, have been phased out on a global scale because of their high environmental persistence and toxicity. As a result, shorter-chain PFAAs with less than 8 carbons in their structure are being used as their replacements and are now widely detected in the environment, raising concerns about their effects on human health. In this study, 47 PFAAs and their precursors were measured in paired samples of dust and drinking water collected from residential homes in Indiana, United States, and in blood and urine samples collected from the residents of these homes. Ultrashort- (with 2 or 3 carbons [C2-C3]) and short-chain (with 4-7 carbons [C4-C7]) PFAAs were the most abundant in all four matrices and constituted on average 69-100% of the total PFAA concentrations. Specifically, trifluoroacetic acid (TFA, C2) and perfluoropropanoic acid (PFPrA, C3) were the predominant PFAAs in most of the samples. Significant positive correlations (n = 81; r = 0.23-0.42; p < 0.05) were found between TFA, perfluorobutanoic acid (PFBA, C4), and perfluoroheptanoic acid (PFHpA, C7) concentrations in dust or water and those in serum, suggesting dust ingestion and/or drinking water consumption as important exposure pathways for these compounds. This study demonstrates that ultrashort- and short-chain PFAAs are now abundant in the indoor environment and in humans and warrants further research on potential adverse health effects of these exposures.
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Affiliation(s)
- Guomao Zheng
- School
of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Stephanie M. Eick
- Gangarosa
Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia 30322, United States
- Department
of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, Georgia 30322, United States
| | - Amina Salamova
- Gangarosa
Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia 30322, United States
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2
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Smeltz M, Wambaugh JF, Wetmore BA. Plasma Protein Binding Evaluations of Per- and Polyfluoroalkyl Substances for Category-Based Toxicokinetic Assessment. Chem Res Toxicol 2023; 36:870-881. [PMID: 37184865 PMCID: PMC10506455 DOI: 10.1021/acs.chemrestox.3c00003] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
New approach methodologies (NAMs) that make use of in vitro screening and in silico approaches to inform chemical evaluations rely on in vitro toxicokinetic (TK) data to translate in vitro bioactive concentrations to exposure metrics reflective of administered dose. With 1364 per- and polyfluoroalkyl substances (PFAS) identified as of interest under Section 8 of the U.S. Toxic Substances Control Act (TSCA) and concern over the lack of knowledge regarding environmental persistence, human health, and ecological effects, the utility of NAMs to understand potential toxicities and toxicokinetics across these data-poor compounds is being evaluated. To address the TK data deficiency, 71 PFAS selected to span a wide range of functional groups and physico-chemical properties were evaluated for in vitro human plasma protein binding (PPB) by ultracentrifugation with liquid chromatography-mass spectrometry analysis. For the 67 PFAS successfully evaluated by ultracentrifugation, fraction unbound in plasma (fup) ranged from less than 0.0001 (pentadecafluorooctanoyl chloride) to 0.7302 (tetrafluorosuccinic acid), with over half of the PFAS showing PPB exceeding 99.5% (fup < 0.005). Category-based evaluations revealed that perfluoroalkanoyl chlorides and perfluorinated carboxylates (PFCAs) with 6-10 carbons were the highest bound, with similar median values for alkyl, ether, and polyether PFCAs. Interestingly, binding was lower for the PFCAs with a carbon chain length of ≥11. Lower binding also was noted for fluorotelomer carboxylic acids when compared to their carbon-equivalent perfluoroalkyl acids. Comparisons of the fup value derived using two PPB methods, ultracentrifugation or rapid equilibrium dialysis (RED), revealed RED failure for a subset of PFAS of high mass and/or predicted octanol-water partition coefficients exceeding 4 due to failure to achieve equilibrium. Bayesian modeling was used to provide uncertainty bounds around fup point estimates for incorporation into TK modeling. This PFAS PPB evaluation and grouping exercise across 67 structures greatly expand our current knowledge and will aid in PFAS NAM development.
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Affiliation(s)
- Marci Smeltz
- Center for Computational Toxicology and Exposure, US EPA Office of Research and Development, Research Triangle Park, NC 27711, USA
- Current Affiliation: Center for Environmental Measurement and Modeling; Research Triangle Park, NC, 27711, USA
| | - John F. Wambaugh
- Center for Computational Toxicology and Exposure, US EPA Office of Research and Development, Research Triangle Park, NC 27711, USA
| | - Barbara A. Wetmore
- Center for Computational Toxicology and Exposure, US EPA Office of Research and Development, Research Triangle Park, NC 27711, USA
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Kissel JC, Titaley IA, Muensterman DJ, Field JA. Evaluating Neutral PFAS for Potential Dermal Absorption from the Gas Phase. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:4951-4958. [PMID: 36917694 DOI: 10.1021/acs.est.2c08835] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Exposures to per- and polyfluoroalkyl substances (PFAS) are of increasing concern. Assessments typically focus only on ingestion and inhalation exposure due to a lack of generally accepted approaches for estimating dermal absorption. Prior work indicates limited dermal absorption of ionic PFAS, but absorption of neutral PFAS has not been examined from the liquid vehicle or from vapor. Partitioning of semivolatile organic compounds from the gas phase to the skin surface (i.e., stratum corneum) is well known, but the potential for partitioning of neutral PFAS from the gas phase to the stratum corneum has yet to be estimated. The SPARC-estimated physicochemical properties were used to calculate transdermal permeability coefficients (kp_g) and dermal-to-inhalation (D/I) exposure ratios for two groups of neutral PFAS, including those on a U.S. Environmental Protection Agency PFAS list. 11 neutral PFAS gave calculated D/I ratios >5, indicating that direct transdermal absorption may be an important exposure pathway compared to inhalation. Data on consumer products or indoor air is needed for the 11 neutral PFAS, followed by possible biomonitoring to experimentally verify dermal absorption from air. Additional PFAS should be estimated by the protocol used here as they are identified in commercial products.
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Affiliation(s)
- John C Kissel
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington 98105, United States
| | - Ivan A Titaley
- Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, Oregon 97331, United States
| | - Derek J Muensterman
- Department of Chemistry, Oregon State University, Corvallis, Oregon 97331, United States
| | - Jennifer A Field
- Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, Oregon 97331, United States
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Yi S, Yang D, Zhu L, Mabury SA. Significant Reductive Transformation of 6:2 Chlorinated Polyfluorooctane Ether Sulfonate to Form Hydrogen-Substituted Polyfluorooctane Ether Sulfonate and Their Toxicokinetics in Male Sprague-Dawley Rats. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:6123-6132. [PMID: 33947185 DOI: 10.1021/acs.est.1c00616] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
6:2 chlorinated polyfluorooctane ether sulfonate (6:2 Cl-PFESA) was previously shown to undergo limited dechlorination in rainbow trout to yield 6:2 hydrogen-substituted polyfluorooctane ether sulfonate (6:2 H-PFESA) as the sole metabolite. However, the biotransformation susceptibility of 6:2 Cl-PFESA has not been investigated in mammals and the biological behavior of 6:2 H-PFESA has not been defined in any species. We investigated the respective transformation products of 6:2 Cl-PFESA and 6:2 H-PFESA and their toxicokinetic properties in male Sprague-Dawley rats as a mammalian model. 6:2 H-PFESA was the sole detectable metabolite of 6:2 Cl-PFESA, with a transformation percentage of 13.6% in rat liver, but it resisted further degradation. 6:2 Cl-PFESA also transformed to 6:2 H-PFESA in reductive rat liver S9 incubations but remained stable under oxidative conditions, suggesting a reductive enzyme-dependent transformation pathway. 6:2 Cl-PFESA was more enriched in lipid-rich tissues, while 6:2 H-PFESA was more prone to cumulative urinary excretion. From this perspective, it may suggest a detoxification mechanism for organisms to form the less hydrophobic 6:2 H-PFESA to alleviate total burdens. To date, 6:2 Cl-PFESA was the second perfluoroalkyl acid reported to undergo biotransformation in mammals. The toxicokinetic properties determined for 6:2 Cl-PFESA and 6:2 H-PFESA in blood and urine were found to be structure and dose dependent.
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Affiliation(s)
- Shujun Yi
- State Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
- Department of Chemistry, University of Toronto, Toronto M5S 3H6, Canada
| | - Diwen Yang
- Department of Chemistry, University of Toronto, Toronto M5S 3H6, Canada
| | - Lingyan Zhu
- State Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Scott A Mabury
- Department of Chemistry, University of Toronto, Toronto M5S 3H6, Canada
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McDonough CA, Li W, Bischel HN, De Silva AO, DeWitt JC. Widening the Lens on PFASs: Direct Human Exposure to Perfluoroalkyl Acid Precursors (pre-PFAAs). ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:6004-6013. [PMID: 35324171 PMCID: PMC10782884 DOI: 10.1021/acs.est.2c00254] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Determining health risks associated with per-/polyfluoroalkyl substances (PFASs) is a highly complex problem requiring massive efforts for scientists, risk assessors, and regulators. Among the most poorly understood pressing questions is the relative importance of pre-PFAAs, which are PFASs that degrade to highly persistent perfluoroalkyl acids. How many of the vast number of existing pre-PFAAs are relevant for direct human exposure, and what are the predominant exposure pathways? What evidence of direct exposure to pre-PFAAs is provided by human biomonitoring studies? How important are pre-PFAAs and their biotransformation products for human health risk assessment? This article outlines recent progress and recommendations toward widening the lens on human PFAS exposure to include the pre-PFAA subclass.
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Affiliation(s)
- Carrie A. McDonough
- Department of Civil Engineering, Stony Brook University, Stony Brook, NY 11794, USA
| | - Wenting Li
- Department of Civil & Environmental Engineering, University of California Davis, Davis, CA 95616 USA
| | - Heather N. Bischel
- Department of Civil & Environmental Engineering, University of California Davis, Davis, CA 95616 USA
| | - Amila O. De Silva
- Aquatic Contaminants Research Division, Water Science Technology Directorate, Environment and Climate Change Canada, Burlington, Ontario L7S 1A1, Canada
| | - Jamie C. DeWitt
- Department of Pharmacology & Toxicology, Brody School of Medicine, East Carolina University, Greenville, NC 27834, USA
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PFAS Molecules: A Major Concern for the Human Health and the Environment. TOXICS 2022; 10:toxics10020044. [PMID: 35202231 PMCID: PMC8878656 DOI: 10.3390/toxics10020044] [Citation(s) in RCA: 75] [Impact Index Per Article: 37.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 01/05/2022] [Accepted: 01/11/2022] [Indexed: 01/09/2023]
Abstract
Per- and polyfluoroalkyl substances (PFAS) are a group of over 4700 heterogeneous compounds with amphipathic properties and exceptional stability to chemical and thermal degradation. The unique properties of PFAS compounds has been exploited for almost 60 years and has largely contributed to their wide applicability over a vast range of industrial, professional and non-professional uses. However, increasing evidence indicate that these compounds represent also a serious concern for both wildlife and human health as a result of their ubiquitous distribution, their extreme persistence and their bioaccumulative potential. In light of the adverse effects that have been already documented in biota and human populations or that might occur in absence of prompt interventions, the competent authorities in matter of health and environment protection, the industries as well as scientists are cooperating to identify the most appropriate regulatory measures, substitution plans and remediation technologies to mitigate PFAS impacts. In this review, starting from PFAS chemistry, uses and environmental fate, we summarize the current knowledge on PFAS occurrence in different environmental media and their effects on living organisms, with a particular emphasis on humans. Also, we describe present and provisional legislative measures in the European Union framework strategy to regulate PFAS manufacture, import and use as well as some of the most promising treatment technologies designed to remediate PFAS contamination in different environmental compartments.
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Herkert NJ, Kassotis CD, Zhang S, Han Y, Pulikkal VF, Sun M, Ferguson PL, Stapleton HM. Characterization of Per- and Polyfluorinated Alkyl Substances Present in Commercial Anti-fog Products and Their In Vitro Adipogenic Activity. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:1162-1173. [PMID: 34985261 PMCID: PMC8908479 DOI: 10.1021/acs.est.1c06990] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Anti-fog sprays and solutions are used on eyeglasses to minimize the condensation of water vapor, particularly while wearing a mask. Given their water-repellent properties, we sought to characterize per- and polyfluorinated alkyl substance (PFAS) compounds in four anti-fog spray products, five anti-fog cloth products, and two commercial fluorosurfactant formulations suspected to be used in preparing anti-fog products. Fluorotelomer alcohols (FTOHs) and fluorotelomer ethoxylates (FTEOs) were detected in all products and formulations. While 6:2 FTOH and the 6:2 FTEO polymeric series were predominant, one anti-fog cloth and one formulation contained 8:2, 10:2, 12:2, 14:2, and 16:2 FTOH and FTEO polymeric series. PFAS concentrations varied in samples and were detected at levels up to 25,000 μg/mL in anti-fog sprays and 185,000 μg (g cloth)-1 in anti-fog cloth products. The total organic fluorine (TOF) measurements of anti-fog products ranged from 190 to 20,700 μg/mL in sprays and 44,200 to 131,500 μg (g cloth)-1 in cloths. Quantified FTOHs and FTEOs accounted for 1-99% of TOF mass. In addition, all four anti-fog sprays and both commercial formulations exhibited significant cytotoxicity and adipogenic activity (either triglyceride accumulation and/or pre-adipocyte proliferation) in murine 3T3-L1 cells. Results suggest that FTEOs are a significant contributor to the adipogenic activity exhibited by the anti-fog sprays. Altogether, these results suggest that FTEOs are present in commercial products at toxicologically relevant levels, and more research is needed to fully understand the health risks from using these PFAS-containing products.
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Affiliation(s)
- Nicholas J Herkert
- Nicholas School of the Environment, Duke University, Box 90328, Durham, North Carolina 27708, United States
| | - Christopher D Kassotis
- Institute of Environmental Health Sciences and Department of Pharmacology, Wayne State University, Detroit, Michigan 48202, United States
| | - Sharon Zhang
- Nicholas School of the Environment, Duke University, Box 90328, Durham, North Carolina 27708, United States
| | - Yuling Han
- Department of Civil and Environmental Engineering, University of North Carolina at Charlotte, Charlotte, North Carolina 28223, United States
| | - Vivek Francis Pulikkal
- Department of Civil and Environmental Engineering, University of North Carolina at Charlotte, Charlotte, North Carolina 28223, United States
| | - Mei Sun
- Department of Civil and Environmental Engineering, University of North Carolina at Charlotte, Charlotte, North Carolina 28223, United States
| | - P Lee Ferguson
- Nicholas School of the Environment, Duke University, Box 90328, Durham, North Carolina 27708, United States
- Department of Civil and Environmental Engineering, Duke University, Durham, North Carolina 27708, United States
| | - Heather M Stapleton
- Nicholas School of the Environment, Duke University, Box 90328, Durham, North Carolina 27708, United States
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Bălan SA, Mathrani VC, Guo DF, Algazi AM. Regulating PFAS as a Chemical Class under the California Safer Consumer Products Program. ENVIRONMENTAL HEALTH PERSPECTIVES 2021; 129:25001. [PMID: 33595352 PMCID: PMC7888260 DOI: 10.1289/ehp7431] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 12/14/2020] [Accepted: 01/13/2021] [Indexed: 05/17/2023]
Abstract
BACKGROUND Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are a group of manmade chemicals containing at least one fully fluorinated carbon atom. The widespread use, large number, and diverse chemical structures of PFAS pose challenges to any sufficiently protective regulation, emissions reduction, and remediation at contaminated sites. Regulating only a subset of PFAS has led to their replacement with other members of the class with similar hazards, that is, regrettable substitutions. Regulations that focus solely on perfluoroalkyl acids (PFAAs) are ineffective, given that nearly all other PFAS can generate PFAAs in the environment. OBJECTIVES In this commentary, we present the rationale adopted by the State of California's Department of Toxic Substances Control (DTSC) for regulating PFAS as a class in certain consumer products. DISCUSSION We at the California DTSC propose regulating certain consumer products if they contain any member of the class of PFAS because: a) all PFAS, or their degradation, reaction, or metabolism products, display at least one common hazard trait according to the California Code of Regulations, namely environmental persistence; and b) certain key PFAS that are the degradation, reaction or metabolism products, or impurities of nearly all other PFAS display additional hazard traits, including toxicity; are widespread in the environment, humans, and biota; and will continue to cause adverse impacts for as long as any PFAS continue to be used. Regulating PFAS as a class is thus logical, necessary, and forward-thinking. This technical position may be helpful to other regulatory agencies in comprehensively addressing this large class of chemicals with common hazard traits. https://doi.org/10.1289/EHP7431.
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Affiliation(s)
- Simona Andreea Bălan
- Safer Consumer Products Program, California Department of Toxic Substances Control, Sacramento, California, USA
| | - Vivek Chander Mathrani
- Safer Consumer Products Program, California Department of Toxic Substances Control, Sacramento, California, USA
| | - Dennis Fengmao Guo
- Safer Consumer Products Program, California Department of Toxic Substances Control, Sacramento, California, USA
| | - André Maurice Algazi
- Safer Consumer Products Program, California Department of Toxic Substances Control, Sacramento, California, USA
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Yi S, Zhu L, Mabury SA. First Report on In Vivo Pharmacokinetics and Biotransformation of Chlorinated Polyfluoroalkyl Ether Sulfonates in Rainbow Trout. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:345-354. [PMID: 31774655 DOI: 10.1021/acs.est.9b05258] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
This study provides the first in vivo pharmacokinetic data for chlorinated perfluorooctanesulfonate (Cl-PFOS), 6:2 and 8:2 chlorinated polyfluoroalkyl ether sulfonates (Cl-PFESAs), upon a 30 day dietary exposure and 34 day depuration phase in rainbow trout (Oncorhynchus mykiss). Biological handling of these three novel molecules and legacy PFOS were investigated via cross-comparison. PFOS and Cl-PFOS displayed comparable bioaccumulative potencies and similar distribution tendencies in tissues (blood > liver > kidneys), despite the presence of a terminal chlorine atom in Cl-PFOS molecule. The Cl-PFESAs, especially 8:2 Cl-PFESA, were predominantly assimilated from the bloodstream by liver and kidneys and resisted elimination, leading to higher bioaccumulation factors in liver than in blood (0.576 and 0.254, respectively, for 8:2 Cl-PFESA) and longer half-lives in liver and kidneys than PFOS, suggesting these alternatives may pose greater risks in terms of the great accumulation potentials in fish tissues. The present study provides the first report of the in vivo transformation of 6:2 and 8:2 Cl-PFESAs and identifies 6:2 and 8:2 H-PFESAs as their respective sole metabolites. This provides the first line of evidence suggesting that the transformation susceptibility of Cl-PFESAs in organisms is distinct from their environmental persistence.
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Affiliation(s)
- Shujun Yi
- State Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, P. R. China
- Department of Chemistry, University of Toronto, Toronto M5S 3H6, Canada
| | - Lingyan Zhu
- State Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, P. R. China
| | - Scott A Mabury
- Department of Chemistry, University of Toronto, Toronto M5S 3H6, Canada
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Huang MC, Robinson VG, Waidyanatha S, Dzierlenga AL, DeVito MJ, Eifrid MA, Gibbs ST, Blystone CR. Toxicokinetics of 8:2 fluorotelomer alcohol (8:2-FTOH) in male and female Hsd:Sprague Dawley SD rats after intravenous and gavage administration. Toxicol Rep 2019; 6:924-932. [PMID: 31516843 PMCID: PMC6728797 DOI: 10.1016/j.toxrep.2019.08.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 08/13/2019] [Accepted: 08/20/2019] [Indexed: 12/28/2022] Open
Abstract
8:2 fluorotelomer is rapidly distributed and eliminated in rats. Perfluorooctanoic acid and 7:3-fluorotelomer acid are detectable metabolites. Sex differences in kinetics were seen only in perfluorooctanoic acid.
Fluorotelomer alcohols (FTOHs) are used in the production of persistent per- and polyfluorinated alkyl substances (PFAS). Rodents and humans metabolize FTOHs to perfluoralkyl carboxylic acids which have several associated toxicities. Thus, understanding the toxicokinetics of these FTOHs and their metabolites will be useful for interpreting their toxicity for humans. Here, male and female Hsd:Sprague-Dawley SD rats were administered a single dose of 8:2-FTOH via gavage (males: 12, 24, 48 mg/kg; females: 40, 80, 160 mg/kg) or IV (males: 12 mg/kg; females: 40 mg/kg). Toxicokinetics of 8:2-FTOH and two primary metabolites, perfluorooctanoic acid (PFOA) and 7:3-fluorotelomer acid (7:3-FTA) were determined in plasma. Concentrations (total) of these chemicals were determined in the liver, kidney, and brain. There was rapid absorption and distribution of 8:2-FTOH after gavage administration in male rats. The plasma elimination half-life ranged from 1.1 to 1.7 hours. Kinetic parameters of 8:2-FTOH in females were similar to that in males. Bioavailability of 8:2-FTOH ranged from 22 to 41% for both sexes with no dose-dependent trends. 8:2-FTOH metabolites, PFOA and 7:3-FTA were detected in plasma following administration of the parent FTOH. Consistent with existing literature, the plasma half-life of PFOA was longer in males than in females (198–353 hours and 4.47–6.9 hours, respectively). The plasma half-life of 7:3-FTA was around 2–3 days in both sexes. 8:2-FTOH and 7:3-FTA were detected in all tissues; PFOA was found in the liver and kidney but not the brain. Detectable concentrations of metabolites persisted longer than the parent FTOH. These data demonstrate that in rats given a single gavage dose, 8:2-FTOH is rapidly absorbed, metabolized to form PFOA and 7:3-FTA, distributed to tissues, and eliminated faster than its metabolites. Sex differences were observed in the tissue distribution and elimination of PFOA, but not 8:2-FTOH and 7:3-FTA.
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Affiliation(s)
- M C Huang
- Division of the National Toxicology Program, National Institutes of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, NC 27709, United States
| | - V G Robinson
- Division of the National Toxicology Program, National Institutes of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, NC 27709, United States
| | - S Waidyanatha
- Division of the National Toxicology Program, National Institutes of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, NC 27709, United States
| | - A L Dzierlenga
- Division of the National Toxicology Program, National Institutes of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, NC 27709, United States
| | - M J DeVito
- Division of the National Toxicology Program, National Institutes of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, NC 27709, United States
| | - M A Eifrid
- Battelle, Columbus, OH, United States.,Charles River Laboratories, Ashland, OH, United States
| | - S T Gibbs
- Battelle, Columbus, OH, United States
| | - C R Blystone
- Division of the National Toxicology Program, National Institutes of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, NC 27709, United States
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11
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Poothong S, Thomsen C, Padilla-Sanchez JA, Papadopoulou E, Haug LS. Distribution of Novel and Well-Known Poly- and Perfluoroalkyl Substances (PFASs) in Human Serum, Plasma, and Whole Blood. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:13388-13396. [PMID: 29056041 DOI: 10.1021/acs.est.7b03299] [Citation(s) in RCA: 112] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Currently, there is limited knowledge on the distribution of poly- and perfluoroalkyl substances (PFASs) in different blood matrices, particularly for novel PFASs such as polyfluoroalkyl phosphate esters (PAPs) and perfluoroalkyl phosphonates (PFPAs). To explore this, serum, plasma, and whole blood from 61 adults in Oslo, Norway were collected. The largest number of PFASs were detected in whole blood. For PAPs and PFPAs, the highest frequencies of detection and concentrations were observed in plasma. PAPs contributed to 8% of total PFASs in plasma (median, 0.81 ng mL-1). Perfluorohexylphosphonate (PFHxPA) was the dominant PFPA, regardless of blood matrix. The relative composition profiles of PFASs in blood matrices differed. For some specific PFASs such as perfluorooctanesulfonamide (PFOSA) and perfluorohexanoate (PFHxA), the highest concentrations were observed in whole blood. The PFAS concentration ratios varied between blood matrices, depending on the compounds. However, similar ratios were observed for 6:2 polyfluoroalkyl phosphate diester (6:2diPAP) as well as well-known PFASs such as perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA). Besides the determination of 25 PFASs in human blood, this study also lead to better understanding of biomonitoring data from different blood matrices, which is key knowledge for performing both exposure assessments and epidemiological studies.
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Affiliation(s)
- Somrutai Poothong
- Department of Environmental Exposure and Epidemiology, Norwegian Institute of Public Health , P.O. Box 4404, Nydalen NO-0403 Oslo, Norway
| | - Cathrine Thomsen
- Department of Environmental Exposure and Epidemiology, Norwegian Institute of Public Health , P.O. Box 4404, Nydalen NO-0403 Oslo, Norway
| | - Juan Antonio Padilla-Sanchez
- Department of Environmental Exposure and Epidemiology, Norwegian Institute of Public Health , P.O. Box 4404, Nydalen NO-0403 Oslo, Norway
| | - Eleni Papadopoulou
- Department of Environmental Exposure and Epidemiology, Norwegian Institute of Public Health , P.O. Box 4404, Nydalen NO-0403 Oslo, Norway
| | - Line Småstuen Haug
- Department of Environmental Exposure and Epidemiology, Norwegian Institute of Public Health , P.O. Box 4404, Nydalen NO-0403 Oslo, Norway
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Joudan S, Yeung LWY, Mabury SA. Biological Cleavage of the C–P Bond in Perfluoroalkyl Phosphinic Acids in Male Sprague-Dawley Rats and the Formation of Persistent and Reactive Metabolites. ENVIRONMENTAL HEALTH PERSPECTIVES 2017; 125:117001. [PMID: 29135439 PMCID: PMC5947941 DOI: 10.1289/ehp1841] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 09/20/2017] [Accepted: 09/21/2017] [Indexed: 05/27/2023]
Abstract
BACKGROUND Perfluoroalkyl phosphinic acids (PFPiAs) have been detected in humans, wildlife, and various environmental matrices. These compounds have been used with perfluoroalkyl phosphonic acids (PFPAs) as surfactants in consumer products and as nonfoaming additives in pesticide formulations. Unlike the structurally related perfluoroalkyl sulfonic and carboxylic acids, little is known about the biological fate of PFPiAs. OBJECTIVES We determined the biotransformation products of PFPiAs and some pharmacokinetic parameters in a rat model. METHODS Male Sprague-Dawley rats received an oral gavage dose of either C6/C8PFPiA, C8/C8PFPiA, or C8PFPA. Blood was sampled over time, and livers were harvested upon sacrifice. Analytes were quantified using ultra-high-performance liquid chromatography-tandem mass spectrometry or gas chromatography-mass spectrometry. RESULTS PFPiAs were metabolized to the corresponding PFPAs and 1H-perfluoroalkanes (1H-PFAs), with 70% and 75% biotransformation 2 wk after a single bolus dose for C6/C8PFPiA and C8/C8PFPiA, respectively. This is the first reported cleavage of a C-P bond in mammals, and the first attempt, with a single-dose exposure, to characterize the degradation of any perfluoroalkyl acid. Elimination half-lives were 1.9±0.5 and 2.8±0.8 days for C6/C8PFPiA and C8/C8PFPiA, respectively, and 0.95±0.17 days for C8PFPA. Although elimination half-lives were not determined for 1H-PFAs, concentrations were higher than the corresponding PFPAs 48 h after rats were dosed with PFPiAs, suggestive of slower elimination. CONCLUSIONS PFPiAs were metabolized in Sprague-Dawley rats to form persistent PFPAs as well as 1H-PFAs, which contain a labile hydrogen that may undergo further metabolism. These results in rats produced preliminary findings of the pharmacokinetics and metabolism of PFPiAs, which should be further investigated in humans. If there is a parallel between the disposition of these chemicals in humans and rats, then humans with detectable amounts of PFPiAs in their blood may be undergoing continuous exposure. https://doi.org/10.1289/EHP1841.
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Affiliation(s)
- Shira Joudan
- Department of Chemistry, University of Toronto, Toronto, Ontario, Canada
| | - Leo W Y Yeung
- Department of Chemistry, University of Toronto, Toronto, Ontario, Canada
| | - Scott A Mabury
- Department of Chemistry, University of Toronto, Toronto, Ontario, Canada
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De Silva AO, Spencer C, Ho KCD, Al Tarhuni M, Go C, Houde M, de Solla SR, Lavoie RA, King LE, Muir DCG, Fair PA, Wells RS, Bossart GD. Perfluoroalkylphosphinic Acids in Northern Pike (Esox lucius), Double-Crested Cormorants (Phalacrocorax auritus), and Bottlenose Dolphins (Tursiops truncatus) in Relation to Other Perfluoroalkyl Acids. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:10903-10913. [PMID: 27677975 DOI: 10.1021/acs.est.6b03515] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Perfluoroalkyl phosphinic acids (PFPIAs) are perfluoroalkyl acids (PFAAs) that are used for their surfactant properties in a variety of applications, resulting in their presence in environmental waters; however, they have not been widely studied in biota. A survey of PFPIAs was conducted in fish, dolphins, and birds from various locations in North America. Northern pike (Esox lucius) were collected at two locations in 2011 near Montréal Island in the St. Lawrence River, Canada, double-crested cormorants (Phalacrocorax auritus) were collected from bird colonies in the Great Lakes in 2010-2012, and bottlenose dolphins (Tursiops truncatus) from Sarasota Bay, FL and Charleston Harbor, SC were sampled in 2004-2009. PFPIAs had a detection frequency of 100% in all animals. This is the first report of PFPIAs in fish, dolphin, and bird plasma. Total PFPIA levels (mean ± standard deviation, 1.87 ± 2.17 ng/g wet weight (ww), range of 0.112-15.3 ng/g ww) were 1-2 orders of magnitude lower than those of perfluoroalkyl carboxylates (PFCA) and perfluoroalkanesulfonates (PFSA) in the same samples. The predominant congeners were 6:8 PFPIA (cormorants and pike) and 6:6 PFPIA (dolphins). Total PFPIAs in cormorants from Hamilton Harbour (5.02 ± 2.80 ng/g ww) were statistically higher than in other areas and taxonomic groups. The ubiquity of PFPIAs warrants further research on sources and effects of these unique compounds.
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Affiliation(s)
- Amila O De Silva
- Environment and Climate Change Canada, Canada Centre for Inland Waters , Burlington, Ontario, L7S 1A1, Canada
| | - Christine Spencer
- Environment and Climate Change Canada, Canada Centre for Inland Waters , Burlington, Ontario, L7S 1A1, Canada
| | - Ki Chung D Ho
- Environment and Climate Change Canada, Canada Centre for Inland Waters , Burlington, Ontario, L7S 1A1, Canada
| | - Mohammed Al Tarhuni
- Environment and Climate Change Canada, Canada Centre for Inland Waters , Burlington, Ontario, L7S 1A1, Canada
| | - Christopher Go
- Environment and Climate Change Canada, Canada Centre for Inland Waters , Burlington, Ontario, L7S 1A1, Canada
| | - Magali Houde
- Environment and Climate Change Canada, Centre Saint-Laurent , Montréal, Quebec H2Y 2E7, Canada
| | - Shane R de Solla
- Environment and Climate Change Canada, Canada Centre for Inland Waters , Burlington, Ontario, L7S 1A1, Canada
| | - Raphael A Lavoie
- Biology Department, Queen's University , 116 Barrie Street, Kingston, Ontario K7L3N6 Canada
| | - Laura E King
- Environment and Climate Change Canada, Canada Centre for Inland Waters , Burlington, Ontario, L7S 1A1, Canada
| | - Derek C G Muir
- Environment and Climate Change Canada, Canada Centre for Inland Waters , Burlington, Ontario, L7S 1A1, Canada
| | - Patricia A Fair
- Center for Coastal Environmental Health and Biomolecular Research, NOS, NOAA , 219 Fort Johnson Road, Charleston, South Carolina 29142, United States
| | - Randall S Wells
- Chicago Zoological Society's Sarasota Dolphin Research Program, Mote Marine Laboratory , 1600 Ken Thompson Parkway, Sarasota, Florida 34236, United States
- Georgia Aquarium , 225 Baker Street, Atlanta, Georgia 30313, United States
| | - Gregory D Bossart
- Georgia Aquarium , 225 Baker Street, Atlanta, Georgia 30313, United States
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