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George AJ, Birnbaum LS. Dioxins vs. PFAS: Science and Policy Challenges. ENVIRONMENTAL HEALTH PERSPECTIVES 2024; 132:85003. [PMID: 39133093 DOI: 10.1289/ehp14449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/13/2024]
Abstract
BACKGROUND Dioxin-like chemicals are a group of ubiquitous environmental toxicants that received intense attention in the last two decades of the 20th century. Through extensive mechanistic research and validation, the global community has agreed upon a regulatory strategy for these chemicals that centers on their common additive activation of a single receptor. Applying these regulations has led to decreased exposure in most populations studied. As dioxin-like chemicals moved out of the limelight, research and media attention has turned to other concerning contaminants, including per- and polyfluoroalkyl substances (PFAS). During the 20th century, PFAS were also being quietly emitted into the environment, but only in the last 20 years have we realized the serious threat they pose to health. There is active debate about how to appropriately classify and regulate the thousands of known PFAS and finding a solution for these "forever chemicals" is of the utmost urgency. OBJECTIVES Here, we compare important features of dioxin-like chemicals and PFAS, including the history, mechanism of action, and effective upstream regulatory strategies, with the objective of gleaning insight from the past to improve strategies for addressing PFAS. DISCUSSION The differences between these two chemical classes means that regulatory strategies for dioxin-like chemicals will not be appropriate for PFAS. PFAS exert toxicity by both receptor-based and nonreceptor-based mechanisms, which complicates mixtures evaluation and stymies efforts to develop inexpensive assays that accurately capture toxicity. Furthermore, dioxin-like chemicals were unwanted byproducts, but PFAS are useful and valuable, which has led to intense resistance against efforts to restrict their production. Nonetheless, useful lessons can be drawn from dioxin-like chemicals and applied to PFAS, including eliminating nonessential production of new PFAS and proactive investment in environmental remediation to address their extraordinarily long environmental persistence. https://doi.org/10.1289/EHP14449.
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Affiliation(s)
- Alex J George
- Integrated Toxicology and Environmental Health Program, Duke University, Durham, North Carolina, USA
- Nicholas School of the Environment, Duke University, Durham, North Carolina, USA
| | - Linda S Birnbaum
- Nicholas School of the Environment, Duke University, Durham, North Carolina, USA
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2
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Rericha Y, St. Mary L, Truong L, McClure R, Martin JK, Leonard SW, Thunga P, Simonich MT, Waters KM, Field JA, Tanguay RL. Diverse PFAS produce unique transcriptomic changes linked to developmental toxicity in zebrafish. FRONTIERS IN TOXICOLOGY 2024; 6:1425537. [PMID: 39104825 PMCID: PMC11298493 DOI: 10.3389/ftox.2024.1425537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Accepted: 06/21/2024] [Indexed: 08/07/2024] Open
Abstract
Per- and polyfluoroalkyl substances (PFAS) are a widespread and persistent class of contaminants posing significant environmental and human health concerns. Comprehensive understanding of the modes of action underlying toxicity among structurally diverse PFAS is mostly lacking. To address this need, we recently reported on our application of developing zebrafish to evaluate a large library of PFAS for developmental toxicity. In the present study, we prioritized 15 bioactive PFAS that induced significant morphological effects and performed RNA-sequencing to characterize early transcriptional responses at a single timepoint (48 h post fertilization) after early developmental exposures (8 h post fertilization). Internal concentrations of 5 of the 15 PFAS were measured from pooled whole fish samples across multiple timepoints between 24-120 h post fertilization, and additional temporal transcriptomics at several timepoints (48-96 h post fertilization) were conducted for Nafion byproduct 2. A broad range of differentially expressed gene counts were identified across the PFAS exposures. Most PFAS that elicited robust transcriptomic changes affected biological processes of the brain and nervous system development. While PFAS disrupted unique processes, we also found that similarities in some functional head groups of PFAS were associated with the disruption in expression of similar gene sets. Body burdens after early developmental exposures to select sulfonic acid PFAS, including Nafion byproduct 2, increased from the 24-96 h post fertilization sampling timepoints and were greater than those of sulfonamide PFAS of similar chain lengths. In parallel, the Nafion byproduct 2-induced transcriptional responses increased between 48 and 96 h post fertilization. PFAS characteristics based on toxicity, transcriptomic effects, and modes of action will contribute to further prioritization of PFAS structures for testing and informed hazard assessment.
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Affiliation(s)
- Yvonne Rericha
- Environmental and Molecular Toxicology Department, College of Agricultural Sciences, Oregon State University, Corvallis, OR, United States
- Sinnhuber Aquatic Research Laboratory, Oregon State University, Corvallis, OR, United States
| | - Lindsey St. Mary
- Environmental and Molecular Toxicology Department, College of Agricultural Sciences, Oregon State University, Corvallis, OR, United States
- Sinnhuber Aquatic Research Laboratory, Oregon State University, Corvallis, OR, United States
| | - Lisa Truong
- Environmental and Molecular Toxicology Department, College of Agricultural Sciences, Oregon State University, Corvallis, OR, United States
- Sinnhuber Aquatic Research Laboratory, Oregon State University, Corvallis, OR, United States
| | - Ryan McClure
- Pacific Northwest National Laboratory, Biological Sciences Division, Richland, WA, United States
| | - J. Kainalu Martin
- Environmental and Molecular Toxicology Department, College of Agricultural Sciences, Oregon State University, Corvallis, OR, United States
| | - Scott W. Leonard
- Environmental and Molecular Toxicology Department, College of Agricultural Sciences, Oregon State University, Corvallis, OR, United States
| | - Preethi Thunga
- Biological Sciences Department, College of Sciences, North Carolina State University, Raleigh, NC, United States
| | - Michael T. Simonich
- Sinnhuber Aquatic Research Laboratory, Oregon State University, Corvallis, OR, United States
| | - Katrina M. Waters
- Environmental and Molecular Toxicology Department, College of Agricultural Sciences, Oregon State University, Corvallis, OR, United States
- Pacific Northwest National Laboratory, Biological Sciences Division, Richland, WA, United States
| | - Jennifer A. Field
- Environmental and Molecular Toxicology Department, College of Agricultural Sciences, Oregon State University, Corvallis, OR, United States
| | - Robyn L. Tanguay
- Environmental and Molecular Toxicology Department, College of Agricultural Sciences, Oregon State University, Corvallis, OR, United States
- Sinnhuber Aquatic Research Laboratory, Oregon State University, Corvallis, OR, United States
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3
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Ooka M, Sakamuru S, Zhao J, Qu Y, Fang Y, Tao D, Huang R, Ferguson S, Reif D, Simeonov A, Xia M. Use of Tox21 screening data to profile PFAS bioactivities on nuclear receptors, cellular stress pathways, and cytochrome p450 enzymes. JOURNAL OF HAZARDOUS MATERIALS 2024; 473:134642. [PMID: 38776814 PMCID: PMC11181952 DOI: 10.1016/j.jhazmat.2024.134642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 05/14/2024] [Accepted: 05/16/2024] [Indexed: 05/25/2024]
Abstract
Per- and poly-fluoroalkyl substances (PFAS) are synthetic chemicals widely used in commercial products. PFAS are a global concern due to their persistence in the environment and extensive associations with adverse health outcomes. While legacy PFAS have been extensively studied, many non-legacy PFAS lack sufficient toxicity information. In this study, we first analyzed the bioactivity of PFAS using Tox21 screening data surveying more than 75 assay endpoints (e.g., nuclear receptors, stress response, and metabolism) to understand the toxicity of non-legacy PFAS and investigate potential new targets of PFAS. From the Tox21 screening data analysis, we confirmed several known PFAS targets/pathways and identified several potential novel targets/pathways of PFAS. To confirm the effect of PFAS on these novel targets/pathways, we conducted several cell- and enzyme-based assays in the follow-up studies. We found PFAS inhibited cytochromes P450s (CYPs), especially CYP2C9 with IC50 values of < 1 µM. Considering PFAS affected other targets/pathways at > 10 µM, PFAS have a higher affinity to CYP2C9. This PFAS-CYP2C9 interaction was further investigated using molecular docking analysis. The result suggested that PFAS directly bind to the active sites of CYP2C9. These findings have important implications to understand the mechanism of PFAS action and toxicity.
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Affiliation(s)
- Masato Ooka
- National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD, USA
| | - Srilatha Sakamuru
- National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD, USA
| | - Jinghua Zhao
- National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD, USA
| | - Yanyan Qu
- National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD, USA
| | - Yuhong Fang
- National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD, USA
| | - Dingyin Tao
- National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD, USA
| | - Ruili Huang
- National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD, USA
| | - Stephen Ferguson
- Division of Translational Toxicology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, USA
| | - David Reif
- Division of Translational Toxicology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, USA
| | - Anton Simeonov
- National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD, USA
| | - Menghang Xia
- National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD, USA.
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4
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Britton KN, Judson RS, Hill BN, Jarema KA, Olin JK, Knapp BR, Lowery M, Feshuk M, Brown J, Padilla S. Using Zebrafish to Screen Developmental Toxicity of Per- and Polyfluoroalkyl Substances (PFAS). TOXICS 2024; 12:501. [PMID: 39058153 PMCID: PMC11281043 DOI: 10.3390/toxics12070501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2024] [Revised: 07/01/2024] [Accepted: 07/02/2024] [Indexed: 07/28/2024]
Abstract
Per- and polyfluoroalkyl substances (PFAS) are found in many consumer and industrial products. While some PFAS, notably perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), are developmentally toxic in mammals, the vast majority of PFAS have not been evaluated for developmental toxicity potential. A concentration-response study of 182 unique PFAS chemicals using the zebrafish medium-throughput, developmental vertebrate toxicity assay was conducted to investigate chemical structural identifiers for toxicity. Embryos were exposed to each PFAS compound (≤100 μM) beginning on the day of fertilization. At 6 days post-fertilization (dpf), two independent observers graded developmental landmarks for each larva (e.g., mortality, hatching, swim bladder inflation, edema, abnormal spine/tail, or craniofacial structure). Thirty percent of the PFAS were developmentally toxic, but there was no enrichment of any OECD structural category. PFOS was developmentally toxic (benchmark concentration [BMC] = 7.48 μM); however, other chemicals were more potent: perfluorooctanesulfonamide (PFOSA), N-methylperfluorooctane sulfonamide (N-MeFOSA), ((perfluorooctyl)ethyl)phosphonic acid, perfluoro-3,6,9-trioxatridecanoic acid, and perfluorohexane sulfonamide. The developmental toxicity profile for these more potent PFAS is largely unexplored in mammals and other species. Based on these zebrafish developmental toxicity results, additional screening may be warranted to understand the toxicity profile of these chemicals in other species.
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Affiliation(s)
- Katy N. Britton
- Oak Ridge Associated Universities Research Participation Program Hosted by EPA, Center for Computational Toxicology and Exposure, Biomolecular and Computational Toxicology Division, Rapid Assay Development Branch, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, USA
| | - Richard S. Judson
- Center for Computational Toxicology and Exposure, Computational Toxicology and Bioinformatics Branch, Research Triangle Park, NC 27711, USA;
| | - Bridgett N. Hill
- Oak Ridge Institute for Science and Education Research Participation Program Hosted by EPA, Center for Computational Toxicology and Exposure, Biomolecular and Computational Toxicology Division, Rapid Assay Development Branch, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, USA; (B.N.H.); (B.R.K.)
| | - Kimberly A. Jarema
- Center for Public Health and Environmental Assessment, Immediate Office, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, USA;
| | - Jeanene K. Olin
- Center for Computational Toxicology and Exposure, Biomolecular and Computational Toxicology Division, Rapid Assay Development Branch, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, USA; (J.K.O.); (M.L.)
| | - Bridget R. Knapp
- Oak Ridge Institute for Science and Education Research Participation Program Hosted by EPA, Center for Computational Toxicology and Exposure, Biomolecular and Computational Toxicology Division, Rapid Assay Development Branch, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, USA; (B.N.H.); (B.R.K.)
| | - Morgan Lowery
- Center for Computational Toxicology and Exposure, Biomolecular and Computational Toxicology Division, Rapid Assay Development Branch, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, USA; (J.K.O.); (M.L.)
| | - Madison Feshuk
- Center for Computational Toxicology and Exposure, Scientific Computing and Data Curation Division, Data Extraction and Quality Evaluation Branch, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, USA;
| | - Jason Brown
- Center for Computational Toxicology and Exposure, Scientific Computing and Data Curation Division, Application Development Branch, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, USA;
| | - Stephanie Padilla
- Center for Computational Toxicology and Exposure, Biomolecular and Computational Toxicology Division, Rapid Assay Development Branch, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, USA; (J.K.O.); (M.L.)
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5
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Santana Rodriguez KJ, Villeneuve DL, Cavallin JE, Blackwell BR, Hoang J, Hofer RN, Jensen KM, Kahl MD, Kutsi RN, Stacy E, Morshead ML, Ankley GT. Examining effects of a novel estrogenic perfluoro-alcohol, 1H,1H,8H,8H-Perfluorooctane-1,8-diol (FC8-diol), using the fathead minnow EcoToxChip. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2024. [PMID: 38961679 DOI: 10.1002/etc.5937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Revised: 04/20/2024] [Accepted: 05/27/2024] [Indexed: 07/05/2024]
Abstract
In a previous in vivo study, adult male fathead minnows (Pimephales promelas) were exposed via water for 4 days to 1H,1H,8H,8H-perfluorooctane-1,8-diol (FC8-diol). The present study expands on the evaluation of molecular responses to this perfluoro-alcohol by analyzing 26 male fathead minnow liver RNA samples from that study (five from each test concentration: 0, 0.018, 0.051, 0.171, and 0.463 mg FC8-diol/L) using fathead minnow EcoToxChips Ver. 1.0. EcoToxChips are a quantitative polymerase chain reaction array that allows for simultaneous measurement of >375 species-specific genes of toxicological interest. Data were analyzed with the online tool EcoToxXplorer. Among the genes analyzed, 62 and 96 were significantly up- and downregulated, respectively, by one or more FC8-diol treatments. Gene expression results from the previous study were validated, showing an upregulation of vitellogenin mRNA (vtg) and downregulation of insulin-like growth factor 1 mRNA (igf1). Additional genes related to estrogen receptor activation including esr2a (estrogen receptor 2a) and esrrb (estrogen related receptor beta) were also affected, providing further confirmation of the estrogenic nature of FC8-diol. Furthermore, genes involved in biological pathways related to lipid and carbohydrate metabolism, innate immune response, endocrine reproduction, and endocrine thyroid were significantly affected. These results both add confidence in the use of the EcoToxChip tool for inferring chemical mode(s) of action and provide further insights into the possible biological effects of FC8-diol. Environ Toxicol Chem 2024;00:1-9. © 2024 SETAC. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.
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Affiliation(s)
- Kelvin J Santana Rodriguez
- Great Lakes Toxicology and Ecology Division, Oak Ridge Institute for Science and Education, US Environmental Protection Agency, Duluth, Minnesota
| | - Daniel L Villeneuve
- Great Lakes Toxicology and Ecology Division, US Environmental Protection Agency, Duluth, Minnesota
| | - Jenna E Cavallin
- Great Lakes Toxicology and Ecology Division, US Environmental Protection Agency, Duluth, Minnesota
| | - Brett R Blackwell
- Great Lakes Toxicology and Ecology Division, US Environmental Protection Agency, Duluth, Minnesota
| | - John Hoang
- Great Lakes Toxicology and Ecology Division, Oak Ridge Institute for Science and Education, US Environmental Protection Agency, Duluth, Minnesota
| | - Rachel N Hofer
- Great Lakes Toxicology and Ecology Division, US Environmental Protection Agency, Duluth, Minnesota
| | - Kathleen M Jensen
- Great Lakes Toxicology and Ecology Division, US Environmental Protection Agency, Duluth, Minnesota
| | - Michael D Kahl
- Great Lakes Toxicology and Ecology Division, US Environmental Protection Agency, Duluth, Minnesota
| | - Robin N Kutsi
- Great Lakes Toxicology and Ecology Division, Oak Ridge Institute for Science and Education, US Environmental Protection Agency, Duluth, Minnesota
| | - Emma Stacy
- Great Lakes Toxicology and Ecology Division, US Environmental Protection Agency, Duluth, Minnesota
| | - Mackenzie L Morshead
- Great Lakes Toxicology and Ecology Division, Oak Ridge Institute for Science and Education, US Environmental Protection Agency, Duluth, Minnesota
| | - Gerald T Ankley
- Great Lakes Toxicology and Ecology Division, US Environmental Protection Agency, Duluth, Minnesota
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6
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Gutsfeld S, Wehmas L, Omoyeni I, Schweiger N, Leuthold D, Michaelis P, Howey XM, Gaballah S, Herold N, Vogs C, Wood C, Bertotto L, Wu GM, Klüver N, Busch W, Scholz S, Schor J, Tal T. Investigation of Peroxisome Proliferator-Activated Receptor Genes as Requirements for Visual Startle Response Hyperactivity in Larval Zebrafish Exposed to Structurally Similar Per- and Polyfluoroalkyl Substances (PFAS). ENVIRONMENTAL HEALTH PERSPECTIVES 2024; 132:77007. [PMID: 39046251 PMCID: PMC11268134 DOI: 10.1289/ehp13667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 05/31/2024] [Accepted: 06/04/2024] [Indexed: 07/25/2024]
Abstract
BACKGROUND Per- and polyfluoroalkyl Substances (PFAS) are synthetic chemicals widely detected in humans and the environment. Exposure to perfluorooctanesulfonic acid (PFOS) or perfluorohexanesulfonic acid (PFHxS) was previously shown to cause dark-phase hyperactivity in larval zebrafish. OBJECTIVES The objective of this study was to elucidate the mechanism by which PFOS or PFHxS exposure caused hyperactivity in larval zebrafish. METHODS Swimming behavior was assessed in 5-d postfertilization (dpf) larvae following developmental (1-4 dpf) or acute (5 dpf) exposure to 0.43 - 7.86 μ M PFOS, 7.87 - 120 μ M PFHxS, or 0.4% dimethyl sulfoxide (DMSO). After developmental exposure and chemical washout at 4 dpf, behavior was also assessed at 5-8 dpf. RNA sequencing was used to identify differences in global gene expression to perform transcriptomic benchmark concentration-response (BMC T ) modeling, and predict upstream regulators in PFOS- or PFHxS-exposed larvae. CRISPR/Cas9-based gene editing was used to knockdown peroxisome proliferator-activated receptors (ppars) pparaa/ab, pparda/db, or pparg at day 0. Knockdown crispants were exposed to 7.86 μ M PFOS or 0.4% DMSO from 1-4 dpf and behavior was assessed at 5 dpf. Coexposure with the ppard antagonist GSK3787 and PFOS was also performed. RESULTS Transient dark-phase hyperactivity occurred following developmental or acute exposure to PFOS or PFHxS, relative to the DMSO control. In contrast, visual startle response (VSR) hyperactivity only occurred following developmental exposure and was irreversible up to 8 dpf. Similar global transcriptomic profiles, BMC T estimates, and enriched functions were observed in PFOS- and PFHxS-exposed larvae, and ppars were identified as putative upstream regulators. Knockdown of pparda/db, but not pparaa/ab or pparg, blunted PFOS-dependent VSR hyperactivity to control levels. This finding was confirmed via antagonism of ppard in PFOS-exposed larvae. DISCUSSION This work identifies a novel adverse outcome pathway for VSR hyperactivity in larval zebrafish. We demonstrate that developmental, but not acute, exposure to PFOS triggered persistent VSR hyperactivity that required ppard function. https://doi.org/10.1289/EHP13667.
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Affiliation(s)
- Sebastian Gutsfeld
- Department of Bioanalytical Ecotoxicology, Chemicals in the Environment Research Section, Helmholtz-Centre for Environmental Research–UFZ, Leipzig, Germany
| | - Leah Wehmas
- Center for Computational Toxicology and Exposure, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, North Carolina, USA
| | - Ifeoluwa Omoyeni
- Department of Bioanalytical Ecotoxicology, Chemicals in the Environment Research Section, Helmholtz-Centre for Environmental Research–UFZ, Leipzig, Germany
| | - Nicole Schweiger
- Department of Bioanalytical Ecotoxicology, Chemicals in the Environment Research Section, Helmholtz-Centre for Environmental Research–UFZ, Leipzig, Germany
| | - David Leuthold
- Department of Bioanalytical Ecotoxicology, Chemicals in the Environment Research Section, Helmholtz-Centre for Environmental Research–UFZ, Leipzig, Germany
| | - Paul Michaelis
- Department of Bioanalytical Ecotoxicology, Chemicals in the Environment Research Section, Helmholtz-Centre for Environmental Research–UFZ, Leipzig, Germany
| | - Xia Meng Howey
- Center for Computational Toxicology and Exposure, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, North Carolina, USA
| | - Shaza Gaballah
- Center for Computational Toxicology and Exposure, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, North Carolina, USA
| | - Nadia Herold
- Department of Bioanalytical Ecotoxicology, Chemicals in the Environment Research Section, Helmholtz-Centre for Environmental Research–UFZ, Leipzig, Germany
| | - Carolina Vogs
- Department of Biomedical Science and Veterinary Public Health, Swedish University of Agricultural Sciences, Uppsala, Sweden
- Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Carmen Wood
- Center for Computational Toxicology and Exposure, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, North Carolina, USA
| | - Luísa Bertotto
- Center for Computational Toxicology and Exposure, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, North Carolina, USA
| | - Gi-Mick Wu
- Research and Development Institute for the Agri-Environment, Quebec, Quebec, Canada
| | - Nils Klüver
- Department of Bioanalytical Ecotoxicology, Chemicals in the Environment Research Section, Helmholtz-Centre for Environmental Research–UFZ, Leipzig, Germany
| | - Wibke Busch
- Department of Bioanalytical Ecotoxicology, Chemicals in the Environment Research Section, Helmholtz-Centre for Environmental Research–UFZ, Leipzig, Germany
| | - Stefan Scholz
- Department of Bioanalytical Ecotoxicology, Chemicals in the Environment Research Section, Helmholtz-Centre for Environmental Research–UFZ, Leipzig, Germany
| | - Jana Schor
- Department of Computational Biology and Chemistry, Chemicals in the Environment Research Section, Helmholtz-Centre for Environmental Research–UFZ, Leipzig, Germany
| | - Tamara Tal
- Department of Bioanalytical Ecotoxicology, Chemicals in the Environment Research Section, Helmholtz-Centre for Environmental Research–UFZ, Leipzig, Germany
- Medical Faculty, University Leipzig, Leipzig, Germany
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7
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Judson RS, Smith D, DeVito M, Wambaugh JF, Wetmore BA, Paul Friedman K, Patlewicz G, Thomas RS, Sayre RR, Olker JH, Degitz S, Padilla S, Harrill JA, Shafer T, Carstens KE. A Comparison of In Vitro Points of Departure with Human Blood Levels for Per- and Polyfluoroalkyl Substances (PFAS). TOXICS 2024; 12:271. [PMID: 38668494 PMCID: PMC11053643 DOI: 10.3390/toxics12040271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Revised: 03/29/2024] [Accepted: 03/30/2024] [Indexed: 04/29/2024]
Abstract
Per- and polyfluoroalkyl substances (PFAS) are widely used, and their fluorinated state contributes to unique uses and stability but also long half-lives in the environment and humans. PFAS have been shown to be toxic, leading to immunosuppression, cancer, and other adverse health outcomes. Only a small fraction of the PFAS in commerce have been evaluated for toxicity using in vivo tests, which leads to a need to prioritize which compounds to examine further. Here, we demonstrate a prioritization approach that combines human biomonitoring data (blood concentrations) with bioactivity data (concentrations at which bioactivity is observed in vitro) for 31 PFAS. The in vitro data are taken from a battery of cell-based assays, mostly run on human cells. The result is a Bioactive Concentration to Blood Concentration Ratio (BCBCR), similar to a margin of exposure (MoE). Chemicals with low BCBCR values could then be prioritized for further risk assessment. Using this method, two of the PFAS, PFOA (Perfluorooctanoic Acid) and PFOS (Perfluorooctane Sulfonic Acid), have BCBCR values < 1 for some populations. An additional 9 PFAS have BCBCR values < 100 for some populations. This study shows a promising approach to screening level risk assessments of compounds such as PFAS that are long-lived in humans and other species.
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Affiliation(s)
- Richard S. Judson
- US Environmental Protection Agency, Research Triangle Park, NC 27711, USA; (D.S.); (M.D.); (J.F.W.); (B.A.W.); (K.P.F.); (G.P.); (R.S.T.); (R.R.S.); (J.H.O.); (S.D.); (S.P.); (J.A.H.); (T.S.); (K.E.C.)
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8
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Qin W, Henneberger L, Glüge J, König M, Escher BI. Baseline Toxicity Model to Identify the Specific and Nonspecific Effects of Per- and Polyfluoroalkyl Substances in Cell-Based Bioassays. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:5727-5738. [PMID: 38394616 PMCID: PMC10993398 DOI: 10.1021/acs.est.3c09950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 02/11/2024] [Accepted: 02/12/2024] [Indexed: 02/25/2024]
Abstract
High-throughput screening is a strategy to identify potential adverse outcome pathways (AOP) for thousands of per- and polyfluoroalkyl substances (PFAS) if the specific effects can be distinguished from nonspecific effects. We hypothesize that baseline toxicity may serve as a reference to determine the specificity of the cell responses. Baseline toxicity is the minimum (cyto)toxicity caused by the accumulation of chemicals in cell membranes, which disturbs their structure and function. A mass balance model linking the critical membrane concentration for baseline toxicity to nominal (i.e., dosed) concentrations of PFAS in cell-based bioassays yielded separate baseline toxicity prediction models for anionic and neutral PFAS, which were based on liposome-water distribution ratios as the sole model descriptors. The specificity of cell responses to 30 PFAS on six target effects (activation of peroxisome proliferator-activated receptor (PPAR) gamma, aryl hydrocarbon receptor, oxidative stress response, and neurotoxicity in own experiments, and literature data for activation of several PPARs and the estrogen receptor) were assessed by comparing effective concentrations to predicted baseline toxic concentrations. HFPO-DA, HFPO-DA-AS, and PFMOAA showed high specificity on PPARs, which provides information on key events in AOPs relevant to PFAS. However, PFAS were of low specificity in the other experimentally evaluated assays and others from the literature. Even if PFAS are not highly specific for certain defined targets but disturb many toxicity pathways with low potency, such effects are toxicologically relevant, especially for hydrophobic PFAS and because PFAS are highly persistent and cause chronic effects. This implicates a heightened need for the risk assessment of PFAS mixtures because nonspecific effects behave concentration-additive in mixtures.
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Affiliation(s)
- Weiping Qin
- Department
of Cell Toxicology, UFZ−Helmholtz
Centre for Environmental Research, Leipzig 04318, Germany
- Environmental
Toxicology, Department of Geosciences, Eberhard
Karls University Tübingen, Schnarrenbergstr. 94-96, Tübingen DE-72076, Germany
| | - Luise Henneberger
- Department
of Cell Toxicology, UFZ−Helmholtz
Centre for Environmental Research, Leipzig 04318, Germany
| | - Juliane Glüge
- Department
of Cell Toxicology, UFZ−Helmholtz
Centre for Environmental Research, Leipzig 04318, Germany
- Institute
of Biogeochemistry and Pollutant Dynamics, ETH Zürich, Zürich 8092, Switzerland
| | - Maria König
- Department
of Cell Toxicology, UFZ−Helmholtz
Centre for Environmental Research, Leipzig 04318, Germany
| | - Beate I. Escher
- Department
of Cell Toxicology, UFZ−Helmholtz
Centre for Environmental Research, Leipzig 04318, Germany
- Environmental
Toxicology, Department of Geosciences, Eberhard
Karls University Tübingen, Schnarrenbergstr. 94-96, Tübingen DE-72076, Germany
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9
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Feng C, Lin Y, Le S, Ji J, Chen Y, Wang G, Xiao P, Zhao Y, Lu D. Suspect, Nontarget Screening, and Toxicity Prediction of Per- and Polyfluoroalkyl Substances in the Landfill Leachate. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:4737-4750. [PMID: 38408453 DOI: 10.1021/acs.est.3c07533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/28/2024]
Abstract
Landfills are the final stage of urban wastes containing perfluoroalkyl and polyfluoroalkyl substances (PFASs). PFASs in the landfill leachate may contaminate the surrounding groundwater. As major environmental pollutants, emerging PFASs have raised global concern. Besides the widely reported legacy PFASs, the distribution and potential toxic effects of numerous emerging PFASs remain unclear, and unknown PFASs still need discovery and characterization. This study proposed a comprehensive method for PFAS screening in leachate samples using suspect and nontarget analysis. A total of 48 PFASs from 10 classes were identified; nine novel PFASs including eight chloroperfluoropolyether carboxylates (Cl-PFPECAs) and bistriflimide (HNTf2) were reported for the first time in the leachate, where Cl-PFPECA-3,1 and Cl-PFPECA-2,2 were first reported in environmental media. Optimized molecular docking models were established for prioritizing the PFASs with potential activity against peroxisome proliferator-activated receptor α and estrogen receptor α. Our results indicated that several emerging PFASs of N-methyl perfluoroalkyl sulfonamido acetic acids (N-MeFASAAs), n:3 fluorotelomer carboxylic acid (n:3 FTCA), and n:2 fluorotelomer sulfonate (n:2 FTSA) have potential health risks that cannot be ignored.
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Affiliation(s)
- Chao Feng
- Shanghai Municipal Center for Disease Control and Prevention, Shanghai 200336, China
- State Environmental Protection Key Laboratory of Environmental Health Impact Assessment of Emerging Contaminants, Shanghai 200336, China
| | - Yuanjie Lin
- Shanghai Municipal Center for Disease Control and Prevention, Shanghai 200336, China
- State Environmental Protection Key Laboratory of Environmental Health Impact Assessment of Emerging Contaminants, Shanghai 200336, China
| | - Sunyang Le
- Shanghai Municipal Center for Disease Control and Prevention, Shanghai 200336, China
- State Environmental Protection Key Laboratory of Environmental Health Impact Assessment of Emerging Contaminants, Shanghai 200336, China
| | - Jieyun Ji
- Shanghai Changning Center for Disease Control and Prevention, Shanghai 200051, China
| | - Yuhang Chen
- Shanghai Municipal Center for Disease Control and Prevention, Shanghai 200336, China
- State Environmental Protection Key Laboratory of Environmental Health Impact Assessment of Emerging Contaminants, Shanghai 200336, China
| | - Guoquan Wang
- Shanghai Municipal Center for Disease Control and Prevention, Shanghai 200336, China
- State Environmental Protection Key Laboratory of Environmental Health Impact Assessment of Emerging Contaminants, Shanghai 200336, China
| | - Ping Xiao
- Shanghai Municipal Center for Disease Control and Prevention, Shanghai 200336, China
- State Environmental Protection Key Laboratory of Environmental Health Impact Assessment of Emerging Contaminants, Shanghai 200336, China
| | - Yunfeng Zhao
- China National Center for Food Safety Risk Assessment, Beijing 100021, China
- NHC Key Laboratory of Food Safety Risk Assessment, Beijing 100021, China
| | - Dasheng Lu
- Shanghai Municipal Center for Disease Control and Prevention, Shanghai 200336, China
- State Environmental Protection Key Laboratory of Environmental Health Impact Assessment of Emerging Contaminants, Shanghai 200336, China
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10
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Azhagiya Singam E, Durkin KA, La Merrill MA, Furlow JD, Wang JC, Smith MT. Prediction of the Interactions of a Large Number of Per- and Poly-Fluoroalkyl Substances with Ten Nuclear Receptors. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:4487-4499. [PMID: 38422483 PMCID: PMC10938639 DOI: 10.1021/acs.est.3c05974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 02/01/2024] [Accepted: 02/02/2024] [Indexed: 03/02/2024]
Abstract
Per- and poly-fluoroalkyl substances (PFASs) are persistent, toxic chemicals that pose significant hazards to human health and the environment. Screening large numbers of chemicals for their ability to act as endocrine disruptors by modulating the activity of nuclear receptors (NRs) is challenging because of the time and cost of in vitro and in vivo experiments. For this reason, we need computational approaches to screen these chemicals and quickly prioritize them for further testing. Here, we utilized molecular modeling and machine-learning predictions to identify potential interactions between 4545 PFASs with ten different NRs. The results show that some PFASs can bind strongly to several receptors. Further, PFASs that bind to different receptors can have very different structures spread throughout the chemical space. Biological validation of these in silico findings should be a high priority.
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Affiliation(s)
| | - Kathleen A. Durkin
- Molecular
Graphics and Computation Facility, College of Chemistry, University of California, Berkeley, California 94720, United States
| | - Michele A. La Merrill
- Department
of Environmental Toxicology, University
of California, Davis, California 95616, United States
| | - J. David Furlow
- Department
of Neurobiology, Physiology and Behavior, University of California, Davis California 95616, United States
| | - Jen-Chywan Wang
- Department
of Nutritional Sciences and Toxicology, University of California, Berkeley, California 94720, United States
| | - Martyn T. Smith
- Division
of Environmental Health Sciences, School of Public Health, University of California Berkeley, Berkeley, California 94720, United States
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11
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Villeneuve DL, Blackwell BR, Bush K, Harrill J, Harris F, Hazemi M, Le M, Stacy E, Flynn KM. Transcriptomics-Based Points of Departure for Daphnia magna Exposed to 18 Per- and Polyfluoroalkyl Substances. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2024. [PMID: 38450772 DOI: 10.1002/etc.5838] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 01/08/2024] [Accepted: 01/27/2024] [Indexed: 03/08/2024]
Abstract
Per- and polyfluoroalkyl substances (PFAS) represent a large group of contaminants of concern based on their widespread use, environmental persistence, and potential toxicity. Many traditional models for estimating toxicity, bioaccumulation, and other toxicological properties are not well suited for PFAS. Consequently, there is a need to generate hazard information for PFAS in an efficient and cost-effective manner. In the present study, Daphnia magna were exposed to multiple concentrations of 22 different PFAS for 24 h in a 96-well plate format. Following exposure, whole-body RNA was extracted and extracts, each representing five exposed individuals, were subjected to RNA sequencing. Following analytical measurements to verify PFAS exposure concentrations and quality control on processed cDNA libraries for sequencing, concentration-response modeling was applied to the data sets for 18 of the tested compounds, and the concentration at which a concerted molecular response occurred (transcriptomic point of departure; tPOD) was calculated. The tPODs, based on measured concentrations of PFAS, generally ranged from 0.03 to 0.58 µM (9.9-350 µg/L; interquartile range). In most cases, these concentrations were two orders of magnitude lower than similarly calculated tPODs for human cell lines exposed to PFAS. They were also lower than apical effect concentrations reported for seven PFAS for which some crustacean or invertebrate toxicity data were available, although there were a few exceptions. Despite being lower than most other available hazard benchmarks, D. magna tPODs were, on average, four orders of magnitude greater than the maximum aqueous concentrations of PFAS measured in Great Lakes tributaries. Overall, this high-throughput transcriptomics assay with D. magna holds promise as a component of a tiered hazard evaluation strategy employing new approach methodologies. Environ Toxicol Chem 2024;00:1-16. © 2024 SETAC. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.
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Affiliation(s)
- Daniel L Villeneuve
- Great Lakes Toxicology and Ecology Division, US Environmental Protection Agency, Duluth, MN, USA
| | - Brett R Blackwell
- Great Lakes Toxicology and Ecology Division, US Environmental Protection Agency, Duluth, MN, USA
- Bioscience Division, Biochemistry and Biotechnology Group, Los Alamos National Laboratory, Los Alamos, NM, USA
| | - Kendra Bush
- Oak Ridge Institute for Science and Education Research Participant at US EPA, Great Lakes Toxicology and Ecology Division, Duluth, MN, USA
| | - Joshua Harrill
- Biomolecular and Computational Toxicology Division, United States Environmental Protection Agency, NC, USA
| | - Felix Harris
- Oak Ridge Institute for Science and Education Research Participant at US EPA, Biomolecular and Computational Toxicology Division, Oak Ridge, NC, USA
| | - Monique Hazemi
- Oak Ridge Institute for Science and Education Research Participant at US EPA, Great Lakes Toxicology and Ecology Division, Duluth, MN, USA
| | - Michelle Le
- Oak Ridge Institute for Science and Education Research Participant at US EPA, Great Lakes Toxicology and Ecology Division, Duluth, MN, USA
| | - Emma Stacy
- Great Lakes Toxicology and Ecology Division, US Environmental Protection Agency, Duluth, MN, USA
| | - Kevin M Flynn
- Great Lakes Toxicology and Ecology Division, US Environmental Protection Agency, Duluth, MN, USA
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12
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Degitz SJ, Olker JH, Denny JS, Degoey PP, Hartig PC, Cardon MC, Eytcheson SA, Haselman JT, Mayasich SA, Hornung MW. In vitro screening of per- and polyfluorinated substances (PFAS) for interference with seven thyroid hormone system targets across nine assays. Toxicol In Vitro 2024; 95:105762. [PMID: 38072180 PMCID: PMC11081714 DOI: 10.1016/j.tiv.2023.105762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 10/31/2023] [Accepted: 12/05/2023] [Indexed: 12/30/2023]
Abstract
The US Environmental Protection Agency is evaluating the ecological and toxicological effects of per- and polyfluorinated chemicals. A number of perfluorinated chemicals have been shown to impact the thyroid axis in vivo suggesting that the thyroid hormone system is a target of these chemicals. The objective of this study was to evaluate the activity of 136 perfluorinated chemicals at seven key molecular initiating events (MIE) within the thyroid axis using nine in vitro assays. The potential MIE targets investigated are Human Iodothyronine Deiodinase 1 (hDIO1), Human Iodothyronine Deiodinase 2 (hDIO2), Human Iodothyronine Deiodinase 3 (hDIO3), Xenopus Iodothyronine Deiodinase (xDIO3); Human Iodotyrosine Deiodinase (hIYD), Xenopus Iodotyrosine Deiodinase (xIYD), Human Thyroid Peroxidase (hTPO); and the serum binding proteins Human Transthyretin (hTTR) and Human Thyroxine Binding Globulin (hTBG). Of the 136 PFAS chemicals tested, 85 had sufficient activity to produce a half-maximal effect concentration (EC50) in at least one of the nine assays. In general, most of these PFAS chemicals did not have strong potency towards the seven MIEs examined, apart from transthyretin binding, for which several PFAS had potency similar to the respective model inhibitor. These data sets identify potentially active PFAS chemicals to prioritize for further testing in orthogonal in vitro assays and at higher levels of biological organization to evaluate their capacity for altering the thyroid hormone system and causing potential adverse health and ecological effects.
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Affiliation(s)
- Sigmund J Degitz
- US Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure (CCTE), Great Lakes Toxicology and Ecology Division (GLTED), Duluth, MN 55804, USA.
| | - Jennifer H Olker
- US Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure (CCTE), Great Lakes Toxicology and Ecology Division (GLTED), Duluth, MN 55804, USA
| | - Jeffery S Denny
- US Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure (CCTE), Great Lakes Toxicology and Ecology Division (GLTED), Duluth, MN 55804, USA
| | - Philip P Degoey
- US Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure (CCTE), Great Lakes Toxicology and Ecology Division (GLTED), Duluth, MN 55804, USA
| | - Phillip C Hartig
- US Environmental Protection Agency, Office of Research and Development Center for Public Health and Environmental Assessment, Public Health and Integrated Toxicology Division, Research Triangle Park, NC 27709, USA
| | - Mary C Cardon
- US Environmental Protection Agency, Office of Research and Development Center for Public Health and Environmental Assessment, Public Health and Integrated Toxicology Division, Research Triangle Park, NC 27709, USA
| | - Stephanie A Eytcheson
- US Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure (CCTE), Great Lakes Toxicology and Ecology Division (GLTED), Duluth, MN 55804, USA; Oak Ridge Institute for Science and Education, Oak Ridge, TN, USA
| | - Jonathan T Haselman
- US Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure (CCTE), Great Lakes Toxicology and Ecology Division (GLTED), Duluth, MN 55804, USA
| | - Sally A Mayasich
- US Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure (CCTE), Great Lakes Toxicology and Ecology Division (GLTED), Duluth, MN 55804, USA; Oak Ridge Institute for Science and Education, Oak Ridge, TN, USA
| | - Michael W Hornung
- US Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure (CCTE), Great Lakes Toxicology and Ecology Division (GLTED), Duluth, MN 55804, USA
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13
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Ford LC, Lin HC, Tsai HHD, Zhou YH, Wright FA, Sedykh A, Shah RR, Chiu WA, Rusyn I. Hazard and risk characterization of 56 structurally diverse PFAS using a targeted battery of broad coverage assays using six human cell types. Toxicology 2024; 503:153763. [PMID: 38423244 PMCID: PMC11214689 DOI: 10.1016/j.tox.2024.153763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Revised: 02/13/2024] [Accepted: 02/23/2024] [Indexed: 03/02/2024]
Abstract
Per- and poly-fluoroalkyl substances (PFAS) are extensively used in commerce leading to their prevalence in the environment. Due to their chemical stability, PFAS are considered to be persistent and bioaccumulative; they are frequently detected in both the environment and humans. Because of this, PFAS as a class (composed of hundreds to thousands of chemicals) are contaminants of very high concern. Little information is available for the vast majority of PFAS, and regulatory agencies lack safety data to determine whether exposure limits or restrictions are needed. Cell-based assays are a pragmatic approach to inform decision-makers on potential health hazards; therefore, we hypothesized that a targeted battery of human in vitro assays can be used to determine whether there are structure-bioactivity relationships for PFAS, and to characterize potential risks by comparing bioactivity (points of departure) to exposure estimates. We tested 56 PFAS from 8 structure-based subclasses in concentration response (0.1-100 μM) using six human cell types selected from target organs with suggested adverse effects of PFAS - human induced pluripotent stem cell (iPSC)-derived hepatocytes, neurons, and cardiomyocytes, primary human hepatocytes, endothelial and HepG2 cells. While many compounds were without effect; certain PFAS demonstrated cell-specific activity highlighting the necessity of using a compendium of in vitro models to identify potential hazards. No class-specific groupings were evident except for some chain length- and structure-related trends. In addition, margins of exposure (MOE) were derived using empirical and predicted exposure data. Conservative MOE calculations showed that most tested PFAS had a MOE in the 1-100 range; ∼20% of PFAS had MOE<1, providing tiered priorities for further studies. Overall, we show that a compendium of human cell-based models can be used to derive bioactivity estimates for a range of PFAS, enabling comparisons with human biomonitoring data. Furthermore, we emphasize that establishing structure-bioactivity relationships may be challenging for the tested PFAS.
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Affiliation(s)
- Lucie C Ford
- Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, TX 77843, USA
| | - Hsing-Chieh Lin
- Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, TX 77843, USA
| | - Han-Hsuan D Tsai
- Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, TX 77843, USA
| | - Yi-Hui Zhou
- Department of Biological Sciences and Statistics, North Carolina State University, Raleigh, NC 27695, USA; Bioinformatics Research Center, North Carolina State University, Raleigh, NC 27695, USA
| | - Fred A Wright
- Department of Biological Sciences and Statistics, North Carolina State University, Raleigh, NC 27695, USA; Bioinformatics Research Center, North Carolina State University, Raleigh, NC 27695, USA
| | | | | | - Weihsueh A Chiu
- Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, TX 77843, USA
| | - Ivan Rusyn
- Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, TX 77843, USA.
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14
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Yi S, Wang J, Wang R, Liu M, Zhong W, Zhu L, Jiang G. Structure-Related Thyroid Disrupting Effect of Perfluorooctanesulfonate-like Substances in Zebrafish Larvae. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:182-193. [PMID: 38156633 DOI: 10.1021/acs.est.3c07003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2024]
Abstract
Chlorinated polyfluorooctane ether sulfonate (6:2 Cl-PFESA), hydrogenated polyfluorooctane ether sulfonate (6:2 H-PFESA), and chlorinated polyfluorooctanesulfonate (Cl-PFOS) share structural similarities with the regulated perfluorooctanesulfonate (PFOS), but their toxic potential is rarely known. Here, the thyroid disrupting potential of these four compounds in zebrafish larvae has been comparably investigated. PFOS, Cl-PFOS, and 6:2 Cl-PFESA were accumulated in the larvae at similar levels, approximately 1.3-1.6 times higher than 6:2 H-PFESA. Additionally, PFOS, Cl-PFOS, and 6:2 Cl-PFESA exhibited stronger disruption than 6:2 H-PFESA on genetic regulation, particularly concerning thyroid hormone (TH) activation and action and on TH homeostasis in both free and total forms of thyroxine (T4) and 3,5,3'-triiodothyronine (T3). These results indicate that chlorination or oxygen insertion does not substantially alter the thyrotoxicity of PFOS, but hydrogenation mitigates it. Molecular docking analysis and the luciferase reporter gene assay provided mechanistic perspectives that the PFOS-like substances could competitively replace THs to bind with TH plasma and membrane transporters, thereby disrupting TH transport and action, respectively. Moreover, they are also potent to disrupt TH synthesis and activation through Na+/K+-dependent transport of I- or competitive binding to the sites of deiodinases.
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Affiliation(s)
- Shujun Yi
- Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Jingwen Wang
- Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Rouyi Wang
- Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Menglin Liu
- Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Wenjue Zhong
- Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Lingyan Zhu
- Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Guibin Jiang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
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15
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Almeida NMS, Bali SK, James D, Wang C, Wilson AK. Binding of Per- and Polyfluoroalkyl Substances (PFAS) to the PPARγ/RXRα-DNA Complex. J Chem Inf Model 2023; 63:7423-7443. [PMID: 37990410 DOI: 10.1021/acs.jcim.3c01384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2023]
Abstract
Nuclear receptors are the fundamental building blocks of gene expression regulation and the focus of many drug targets. While binding to DNA, nuclear receptors act as transcription factors, governing a multitude of functions in the human body. Peroxisome proliferator-activator receptor γ (PPARγ) and the retinoid X receptor α (RXRα) form heterodimers with unique properties and have a primordial role in insulin sensitization. This PPARγ/RXRα heterodimer has been shown to be impacted by per- and polyfluoroalkyl substances (PFAS) and linked to a variety of significant health conditions in humans. Herein, a selection of the most common PFAS (legacy and emerging) was studied utilizing molecular dynamics simulations for PPARγ/RXRα. The local and global structural effects of PFAS binding on the known ligand binding pockets of PPARγ and RXRα as well as the DNA binding domain (DBD) of RXRα were inspected. The binding free energies were predicted computationally and were compared between the different binding pockets. In addition, two electronic structure approaches were utilized to model the interaction of PFAS within the DNA binding domain, density functional theory (DFT) and domain-based pair natural orbital coupled cluster with perturbative triples (DLPNO-CCSD(T)) approaches, with implicit solvation. Residue decomposition and hydrogen-bonding analysis were also performed, detailing the role of prominent residues in molecular recognition. The role of l-carnitine is explored as a potential in vivo remediation strategy for PFAS interaction with the PPARγ/RXRα heterodimer. In this work, it was found that PFAS can bind and act as agonists for all of the investigated pockets. For the first time in the literature, PFAS are postulated to bind to the DNA binding domain in a nonspecific manner. In addition, for the PPARγ ligand binding domain, l-carnitine shows promise in replacing smaller PFAS from the pocket.
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Affiliation(s)
- Nuno M S Almeida
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48864, United States
| | - Semiha Kevser Bali
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48864, United States
| | - Deepak James
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48864, United States
| | - Cong Wang
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48864, United States
| | - Angela K Wilson
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48864, United States
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16
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Robarts DR, Dai J, Lau C, Apte U, Corton JC. Hepatic Transcriptome Comparative In Silico Analysis Reveals Similar Pathways and Targets Altered by Legacy and Alternative Per- and Polyfluoroalkyl Substances in Mice. TOXICS 2023; 11:963. [PMID: 38133364 PMCID: PMC10748317 DOI: 10.3390/toxics11120963] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 11/20/2023] [Accepted: 11/25/2023] [Indexed: 12/23/2023]
Abstract
Per- and poly-fluoroalkyl substances (PFAS) are a large class of fluorinated carbon chains that include legacy PFAS, such as perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), and perfluorohexane sulfonate (PFHxS). These compounds induce adverse health effects, including hepatotoxicity. Potential alternatives to the legacy PFAS (HFPO-DA (GenX), HFPO4, HFPO-TA, F-53B, 6:2 FTSA, and 6:2 FTCA), as well as a byproduct of PFAS manufacturing (Nafion BP2), are increasingly being found in the environment. The potential hazards of these new alternatives are less well known. To better understand the diversity of molecular targets of the PFAS, we performed a comparative toxicogenomics analysis of the gene expression changes in the livers of mice exposed to these PFAS, and compared these to five activators of PPARα, a common target of many PFAS. Using hierarchical clustering, pathway analysis, and predictive biomarkers, we found that most of the alternative PFAS modulate molecular targets that overlap with legacy PFAS. Only three of the 11 PFAS tested did not appreciably activate PPARα (Nafion BP2, 6:2 FTSA, and 6:2 FTCA). Predictive biomarkers showed that most PFAS (PFHxS, PFOA, PFOS, PFNA, HFPO-TA, F-53B, HFPO4, Nafion BP2) activated CAR. PFNA, PFHxS, PFOA, PFOS, HFPO4, HFPO-TA, F-53B, Nafion BP2, and 6:2 FTSA suppressed STAT5b, activated NRF2, and activated SREBP. There was no apparent relationship between the length of the carbon chain, type of head group, or number of ether linkages and the transcriptomic changes. This work highlights the similarities in molecular targets between the legacy and alternative PFAS.
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Affiliation(s)
- Dakota R. Robarts
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160, USA
- Center for Computational Toxicology and Exposure, US Environmental Protection Agency, Research Triangle Park, NC 27711, USA
| | - Jiayin Dai
- State Environmental Protection Key Laboratory of Environmental Health Impact Assessment of Emerging Contaminants, School of Environmental Sciences and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Christopher Lau
- Center for Public Health and Environmental Assessment, US Environmental Protection Agency, Research Triangle Park, NC 27711, USA
| | - Udayan Apte
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - J. Christopher Corton
- Center for Computational Toxicology and Exposure, US Environmental Protection Agency, Research Triangle Park, NC 27711, USA
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17
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Conley JM, Lambright CS, Evans N, Farraj AK, Smoot J, Grindstaff RD, Hill D, McCord J, Medlock-Kakaley E, Dixon A, Hines E, Gray LE. Dose additive maternal and offspring effects of oral maternal exposure to a mixture of three PFAS (HFPO-DA, NBP2, PFOS) during pregnancy in the Sprague-Dawley rat. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 892:164609. [PMID: 37271399 PMCID: PMC10681034 DOI: 10.1016/j.scitotenv.2023.164609] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 05/30/2023] [Accepted: 05/30/2023] [Indexed: 06/06/2023]
Abstract
Simultaneous exposure to multiple per- and polyfluoroalkyl substances (PFAS) is common in humans across the globe. Individual PFAS are associated with adverse health effects, yet the nature of mixture effects after exposure to two or more PFAS remains unclear. Previously we reported that oral administration of hexafluoropropylene oxide-dimer acid (HFPO-DA, or GenX), Nafion byproduct 2 (NBP2), or perfluorooctane sulfonate (PFOS) individually during pregnancy produced maternal and F1 effects. Here, we hypothesized that responses to the combined exposure to these three PFAS would be dose additive. Pregnant Sprague-Dawley rats were exposed to a fixed-ratio equipotent mixture where the top dose contained each PFAS at their ED50 for neonatal mortality (100 % dose = PFOS 3 mg/kg; NBP2 10 mg/kg; HFPO-DA 110 mg/kg), followed by a dilution series (33.3, 10, 3.3, and 1 %) and vehicle controls (0 % dose). Consistent with the single chemical studies, dams were exposed from gestation day (GD)14-18 or from GD8-postnatal day (PND2). Fetal and maternal livers on GD18 displayed multiple significantly upregulated genes associated with lipid and carbohydrate metabolism at all dose levels, while dams displayed significantly increased liver weight (≥3.3 % dose) and reduced serum thyroid hormones (≥33.3 % dose). Maternal exposure from GD8-PND2 significantly reduced pup bodyweights at birth (≥33.3 % dose) and PND2 (all doses), increased neonatal liver weights (≥3.3 % dose), increased pup mortality (≥3.3 % dose), and reduced maternal bodyweights and weight gain at the top dose. Echocardiography of adult F1 males and females identified significantly increased left ventricular anterior wall thickness (~10 % increase), whereas other cardiac morphological, functional, and transcriptomic measures were unaffected. Mixture effects in maternal and neonatal animals conformed to dose addition using a relative potency factor (RPF) analysis. Results support dose addition-based cumulative assessment approaches for estimating combined effects of PFAS co-exposure.
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Affiliation(s)
- Justin M Conley
- U.S. Environmental Protection Agency, Office of Research & Development, Center for Public Health and Environmental Assessment, Research Triangle Park, NC, USA.
| | - Christy S Lambright
- U.S. Environmental Protection Agency, Office of Research & Development, Center for Public Health and Environmental Assessment, Research Triangle Park, NC, USA.
| | - Nicola Evans
- U.S. Environmental Protection Agency, Office of Research & Development, Center for Public Health and Environmental Assessment, Research Triangle Park, NC, USA.
| | - Aimen K Farraj
- U.S. Environmental Protection Agency, Office of Research & Development, Center for Public Health and Environmental Assessment, Research Triangle Park, NC, USA.
| | - Jacob Smoot
- ORISE Participant, U.S. Environmental Protection Agency, Office of Research & Development, Center for Public Health and Environmental Assessment, Research Triangle Park, NC, USA.
| | - Rachel D Grindstaff
- U.S. Environmental Protection Agency, Office of Research & Development, Center for Public Health and Environmental Assessment, Research Triangle Park, NC, USA
| | - Donna Hill
- U.S. Environmental Protection Agency, Office of Research & Development, Center for Public Health and Environmental Assessment, Research Triangle Park, NC, USA.
| | - James McCord
- U.S. Environmental Protection Agency, Office of Research & Development, Center for Environmental Measurement and Modeling, Research Triangle Park, NC, USA.
| | - Elizabeth Medlock-Kakaley
- U.S. Environmental Protection Agency, Office of Research & Development, Center for Public Health and Environmental Assessment, Research Triangle Park, NC, USA.
| | - Aaron Dixon
- U.S. Environmental Protection Agency, Office of Research & Development, Center for Public Health and Environmental Assessment, Research Triangle Park, NC, USA.
| | - Erin Hines
- U.S. Environmental Protection Agency, Office of Research & Development, Center for Public Health and Environmental Assessment, Research Triangle Park, NC, USA.
| | - L Earl Gray
- U.S. Environmental Protection Agency, Office of Research & Development, Center for Public Health and Environmental Assessment, Research Triangle Park, NC, USA.
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Cathey AL, Nguyen VK, Colacino JA, Woodruff TJ, Reynolds P, Aung MT. Exploratory profiles of phenols, parabens, and per- and poly-fluoroalkyl substances among NHANES study participants in association with previous cancer diagnoses. JOURNAL OF EXPOSURE SCIENCE & ENVIRONMENTAL EPIDEMIOLOGY 2023; 33:687-698. [PMID: 37718377 PMCID: PMC10541322 DOI: 10.1038/s41370-023-00601-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 08/22/2023] [Accepted: 08/23/2023] [Indexed: 09/19/2023]
Abstract
BACKGROUND Some hormonally active cancers have low survival rates, but a large proportion of their incidence remains unexplained. Endocrine disrupting chemicals may affect hormone pathways in the pathology of these cancers. OBJECTIVE To evaluate cross-sectional associations between per- and polyfluoroalkyl substances (PFAS), phenols, and parabens and self-reported previous cancer diagnoses in the National Health and Nutrition Examination Survey (NHANES). METHODS We extracted concentrations of 7 PFAS and 12 phenols/parabens and self-reported diagnoses of melanoma and cancers of the thyroid, breast, ovary, uterus, and prostate in men and women (≥20 years). Associations between previous cancer diagnoses and an interquartile range increase in exposure biomarkers were evaluated using logistic regression models adjusted for key covariates. We conceptualized race as social construct proxy of structural social factors and examined associations in non-Hispanic Black, Mexican American, and other Hispanic participants separately compared to White participants. RESULTS Previous melanoma in women was associated with higher PFDE (OR:2.07, 95% CI: 1.25, 3.43), PFNA (OR:1.72, 95% CI: 1.09, 2.73), PFUA (OR:1.76, 95% CI: 1.07, 2.89), BP3 (OR: 1.81, 95% CI: 1.10, 2.96), DCP25 (OR: 2.41, 95% CI: 1.22, 4.76), and DCP24 (OR: 1.85, 95% CI: 1.05, 3.26). Previous ovarian cancer was associated with higher DCP25 (OR: 2.80, 95% CI: 1.08, 7.27), BPA (OR: 1.93, 95% CI: 1.11, 3.35) and BP3 (OR: 1.76, 95% CI: 1.00, 3.09). Previous uterine cancer was associated with increased PFNA (OR: 1.55, 95% CI: 1.03, 2.34), while higher ethyl paraben was inversely associated (OR: 0.31, 95% CI: 0.12, 0.85). Various PFAS were associated with previous ovarian and uterine cancers in White women, while MPAH or BPF was associated with previous breast cancer among non-White women. IMPACT STATEMENT Biomarkers across all exposure categories (phenols, parabens, and per- and poly- fluoroalkyl substances) were cross-sectionally associated with increased odds of previous melanoma diagnoses in women, and increased odds of previous ovarian cancer was associated with several phenols and parabens. Some associations differed by racial group, which is particularly impactful given the established racial disparities in distributions of exposure to these chemicals. This is the first epidemiological study to investigate exposure to phenols in relation to previous cancer diagnoses, and the first NHANES study to explore racial/ethnic disparities in associations between environmental phenol, paraben, and PFAS exposures and historical cancer diagnosis.
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Affiliation(s)
- Amber L Cathey
- Department of Environmental Health Sciences, University of Michigan, School of Public Health, Ann Arbor, MI, USA
| | - Vy K Nguyen
- Department of Environmental Health Sciences, University of Michigan, School of Public Health, Ann Arbor, MI, USA
- Department of Biomedical Informatics, Harvard Medical School, Boston, MA, USA
| | - Justin A Colacino
- Department of Environmental Health Sciences, University of Michigan, School of Public Health, Ann Arbor, MI, USA
| | - Tracey J Woodruff
- Program on Reproductive Health and the Environment, Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California, San Francisco, San Francisco, CA, USA
| | - Peggy Reynolds
- Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, CA, USA
| | - Max T Aung
- Department of Population and Public Health Sciences, University of Southern California, Keck School of Medicine, Los Angeles, CA, USA.
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Spyrakis F, Dragani TA. The EU's Per- and Polyfluoroalkyl Substances (PFAS) Ban: A Case of Policy over Science. TOXICS 2023; 11:721. [PMID: 37755732 PMCID: PMC10536631 DOI: 10.3390/toxics11090721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2023] [Revised: 08/16/2023] [Accepted: 08/19/2023] [Indexed: 09/28/2023]
Abstract
The proposal by the European Chemicals Agency (ECHA) to ban over 12,000 per- and polyfluoroalkyl substances (PFAS) has sparked a debate about potential consequences for the economy, industry, and the environment. Although some PFAS are known to be harmful, a blanket ban may lead to significant problems in attempting to replace PFAS-based materials for environmental transition, as well as in medical devices and everyday products. Alternative materials may potentially be less safe, as a rush to replace PFAS would reduce the time needed for toxicological analyses. Studies have shown that PFAS exhibit a diverse range of mechanisms of action, biopersistence, and bioaccumulation potential, and should thus not be treated as a single group. This is particularly true for the class of fluoropolymers. A targeted approach that considers the specific risks and benefits of each chemical may be more effective. Moreover, the proposed ban may also have unintended consequences for the environment as PFAS use is also associated with benefits such as reducing greenhouse-gas emissions and improving energy efficiency. Policymakers must carefully weigh up the potential consequences before making a final decision on the ban.
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Affiliation(s)
- Francesca Spyrakis
- Department of Drug Science and Technology, University of Turin, 10125 Turin, Italy;
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20
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Gong Y, Yang D, Liu J, Barrett H, Sun J, Peng H. Disclosing Environmental Ligands of L-FABP and PPARγ: Should We Re-evaluate the Chemical Safety of Hydrocarbon Surfactants? ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:11913-11925. [PMID: 37527448 DOI: 10.1021/acs.est.3c02898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/03/2023]
Abstract
Chemical contaminants can cause adverse effects by binding to the liver-fatty acid binding protein (L-FABP) and peroxisome proliferator-activated nuclear receptor γ (PPARγ), which are vital in lipid metabolism. However, the presence of numerous compounds in the environment has hindered the identification of their ligands, and thus only a small portion have been discovered to date. In this study, protein Affinity Purification with Nontargeted Analysis (APNA) was employed to identify the ligands of L-FABP and PPARγ in indoor dust and sewage sludge. A total of 83 nonredundant features were pulled-out by His-tagged L-FABP as putative ligands, among which 13 were assigned as fatty acids and hydrocarbon surfactants. In contrast, only six features were isolated when His-tagged PPARγ LBD was used as the protein bait. The binding of hydrocarbon surfactants to L-FABP and PPARγ was confirmed using both recombinant proteins and reporter cells. These hydrocarbon surfactants, along with >50 homologues and isomers, were detected in dust and sludge at high concentrations. Fatty acids and hydrocarbon surfactants explained the majority of L-FABP (57.7 ± 32.9%) and PPARγ (66.0 ± 27.1%) activities in the sludge. This study revealed hydrocarbon surfactants as the predominant synthetic ligands of L-FABP and PPARγ, highlighting the importance of re-evaluating their chemical safety.
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Affiliation(s)
- Yufeng Gong
- Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada
| | - Diwen Yang
- Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada
| | - Jiabao Liu
- Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada
- The Donnelly Centre, University of Toronto, Toronto, Ontario M5S 3H6, Canada
| | - Holly Barrett
- Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada
| | - Jianxian Sun
- Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada
| | - Hui Peng
- Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada
- School of the Environment, University of Toronto, Toronto, Ontario M5S 3H6, Canada
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21
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Ateia M, Sigmund G, Bentel MJ, Washington JW, Lai A, Merrill NH, Wang Z. Integrated data-driven cross-disciplinary framework to prevent chemical water pollution. ONE EARTH (CAMBRIDGE, MASS.) 2023; 6:10.1016/j.oneear.2023.07.001. [PMID: 38264630 PMCID: PMC10802893 DOI: 10.1016/j.oneear.2023.07.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2024]
Abstract
Access to a clean and healthy environment is a human right and a prerequisite for maintaining a sustainable ecosystem. Experts across domains along the chemical life cycle have traditionally operated in isolation, leading to limited connectivity between upstream chemical innovation to downstream development of water-treatment technologies. This fragmented and historically reactive approach to managing emerging contaminants has resulted in significant externalized societal costs. Herein, we propose an integrated data-driven framework to foster proactive action across domains to effectively address chemical water pollution. By implementing this integrated framework, it will not only enhance the capabilities of experts in their respective fields but also create opportunities for novel approaches that yield co-benefits across multiple domains. To successfully operationalize the integrated framework, several concerted efforts are warranted, including adopting open and FAIR (findable, accessible, interoperable, and reusable) data practices, developing common knowledge bases/platforms, and staying vigilant against new substance "properties" of concern.
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Affiliation(s)
- Mohamed Ateia
- United States Environmental Protection Agency, Center for Environmental Solutions & Emergency Response, Cincinnati, OH 45220, USA
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX, USA
| | - Gabriel Sigmund
- Environmental Geosciences, Centre for Microbiology and Environmental Systems Science, University of Vienna, Josef-Holaubeck-Platz 2, 1090 Vienna, Austria
- Environmental Technology, Wageningen University & Research, P.O. Box 17, 6700 AA Wageningen, the Netherlands
| | - Michael J. Bentel
- Department of Environmental Engineering and Earth Sciences, Clemson University, Clemson, SC 29634, USA
| | - John W. Washington
- United States Environmental Protection Agency, Center for Environmental Measurement and Modeling, Athens, GA 30605, USA
| | - Adelene Lai
- Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, 6 Avenue du Swing, 4367 Belvaux, Luxembourg
- Institute for Inorganic and Analytical Chemistry, Friedrich-Schiller-University, 07743 Jena, Germany
| | - Nathaniel H. Merrill
- United States Environmental Protection Agency, Center for Environmental Measurement and Modeling, Narragansett, RI, USA
| | - Zhanyun Wang
- Empa Swiss – Federal Laboratories for Materials Science and Technology, Technology and Society Laboratory, 9014 St. Gallen, Switzerland
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Solan ME, Lavado R. Effects of short-chain per- and polyfluoroalkyl substances (PFAS) on human cytochrome P450 (CYP450) enzymes and human hepatocytes: An in vitro study. Curr Res Toxicol 2023; 5:100116. [PMID: 37575337 PMCID: PMC10412865 DOI: 10.1016/j.crtox.2023.100116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 07/14/2023] [Accepted: 07/18/2023] [Indexed: 08/15/2023] Open
Abstract
Short-chain per- and polyfluoroalkyl substances (PFAS) have been developed as alternatives to legacy long-chain PFAS, but they may still pose risks due to their potential to interact with biomolecules. Cytochrome P450 (CYP450) enzymes are essential for xenobiotic metabolism, and disruptions of these enzymes by PFAS can have significant human health implications. The inhibitory potential of two legacy long-chain (PFOA and PFOS) and five short-chain alternative PFAS (PFBS, PFHxA, HFPO-DA, PFHxS, and 6:2 FTOH) were assessed in recombinant CYP1A2, - 2B6, -2C19, -2E1, and -3A4 enzymes. Most of the short-chain PFAS, except for PFHxS, tested did not result in significant inhibition up to 100 μM. PFOS inhibited recombinant CYP1A2, -2B6, -2C19, and -3A4 enzymes. However, concentrations where inhibition occurred, were all higher than the averages reported in population biomonitoring studies, with IC50 values higher than 10 µM. We also evaluated the activities of CYP1A2 and CYP3A4 in HepaRG monolayers following 48 h exposures of the short-chain PFAS at two concentrations (1 nM or 1 µM) and with or without an inducer (benzo[a]pyrene, BaP, for CYP1A2 and rifampicin for CYP3A4). Our findings suggest that both 1 nM and 1 µM exposures to short-chain PFAS can modulate the CYP1A2 activity induced by BaP. Except for PFHxS, the short-chain PFAS appear to have little effect on CYP3A4 activity. Understanding the effects of PFAS exposure on biotransformation can shed light on the mechanisms of PFAS toxicity and aid in developing effective strategies for managing chemical risks, enabling regulators to make more informed decisions.
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Affiliation(s)
- Megan E. Solan
- Department of Environmental Science, Baylor University, Waco, TX 76798, United States
| | - Ramon Lavado
- Department of Environmental Science, Baylor University, Waco, TX 76798, United States
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23
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Beccacece L, Costa F, Pascali JP, Giorgi FM. Cross-Species Transcriptomics Analysis Highlights Conserved Molecular Responses to Per- and Polyfluoroalkyl Substances. TOXICS 2023; 11:567. [PMID: 37505532 PMCID: PMC10385990 DOI: 10.3390/toxics11070567] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 06/25/2023] [Accepted: 06/28/2023] [Indexed: 07/29/2023]
Abstract
In recent decades, per- and polyfluoroalkyl substances (PFASs) have garnered widespread public attention due to their persistence in the environment and detrimental effects on the health of living organisms, spurring the generation of several transcriptome-centered investigations to understand the biological basis of their mechanism. In this study, we collected 2144 publicly available samples from seven distinct animal species to examine the molecular responses to PFAS exposure and to determine if there are conserved responses. Our comparative transcriptional analysis revealed that exposure to PFAS is conserved across different tissues, molecules and species. We identified and reported several genes exhibiting consistent and evolutionarily conserved transcriptional response to PFASs, such as ESR1, HADHA and ID1, as well as several pathways including lipid metabolism, immune response and hormone pathways. This study provides the first evidence that distinct PFAS molecules induce comparable transcriptional changes and affect the same metabolic processes across inter-species borders. Our findings have significant implications for understanding the impact of PFAS exposure on living organisms and the environment. We believe that this study offers a novel perspective on the molecular responses to PFAS exposure and provides a foundation for future research into developing strategies for mitigating the detrimental effects of these substances in the ecosystem.
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Affiliation(s)
- Livia Beccacece
- Department of Pharmacy and Biotechnology, University of Bologna, 40126 Bologna, Italy
| | - Filippo Costa
- Department of Pharmacy and Biotechnology, University of Bologna, 40126 Bologna, Italy
| | - Jennifer Paola Pascali
- Department of Cardiac, Thoracic, Vascular Sciences and Public Health, University of Padua, 35121 Padua, Italy
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24
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Chaney C, Wiley KS. The variable associations between PFASs and biological aging by sex and reproductive stage in NHANES 1999-2018. ENVIRONMENTAL RESEARCH 2023; 227:115714. [PMID: 36965790 DOI: 10.1016/j.envres.2023.115714] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 01/31/2023] [Accepted: 03/16/2023] [Indexed: 05/08/2023]
Abstract
BACKGROUND Per- and polyfluoroalkyl substances (PFASs) are endocrine disrupting chemicals that have myriad effects on human physiology. Estrogenic PFASs may influence biological aging by mimicking the activity of endogenous estrogens, which can decrease inflammation and oxidative stress and enhance telomerase activity. We hypothesized that PFAS exposure would be differentially associated with measures of biological aging based on biological sex and reproductive stage. METHODS We analyzed associations between serum PFAS levels and measures of biological aging for pre- and postmenopausal women and men (n = 3193) using data from the 2003 to 2018 waves of the National Health and Nutrition Examination Survey. Examining PFASs both individually and in mixture models, we investigated four measures of clinical aging (Homeostatic Dysregulation, the Klemera-Doubal Method, Phenotypic Age Acceleration, and Allostatic Load), oxidative stress, and telomere length. RESULTS PFOA and PFOS were negatively associated with Phenotypic Age Acceleration (e.g. decelerated aging) for men B = -0.22, 95% CI: -0.32, -0.12; B = -0.04, 95% CI: -0.06, -0.03) , premenopausal women (B = -0.58, 95% CI: -0.83, -0.32; B = -0.15, 95% CI: -0.20, -0.09), and postmenopausal women (B= -0.22, 95% CI: -0.43, -0.01; B = -0.05, 95% CI: -0.08, -0.02). In mixture models, we found net negative effects for Phenotypic Age Acceleration and Allostatic Load for men, premenopausal women, and postmenopausal women. We also found significant mixture effects for the antioxidants bilirubin and albumin among the three sample groups. We found no evidence to support effects on telomere length. DISCUSSION Our findings suggest that PFAS exposure may be inversely associated with some measures of biological aging at the relatively low levels of exposure in this sample, regardless of reproductive stage and sex, which does not support our hypothesis. This research provides insights into how PFAS exposure may variably influence aging measures depending on the physiological process investigated.
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Affiliation(s)
- C Chaney
- Department of Anthropology, Yale University, New Haven, CT, USA.
| | - K S Wiley
- Department of Anthropology, University of California, Los Angeles, CA, USA; Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, CA, USA
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25
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Xu Y, Jakobsson K, Harari F, Andersson EM, Li Y. Exposure to high levels of PFAS through drinking water is associated with increased risk of type 2 diabetes-findings from a register-based study in Ronneby, Sweden. ENVIRONMENTAL RESEARCH 2023; 225:115525. [PMID: 36813069 DOI: 10.1016/j.envres.2023.115525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Revised: 02/03/2023] [Accepted: 02/18/2023] [Indexed: 06/18/2023]
Abstract
BACKGROUND Epidemiological studies linking type 2 diabetes (T2D) and exposure to per- and polyfluoroalkyl substances (PFAS), are limited and have yielded conflicting results. This register-based study aimed to investigate the risk of T2D among Swedish adults who had been exposed to PFAS from highly contaminated drinking water for decades. METHODS The study included 55,032 adults (aged ≥18 years) from the Ronneby Register Cohort, who ever lived in Ronneby during 1985-2013. Exposure was assessed using the yearly residential address and the absence ("never-high") or presence ("ever-high") of high PFAS contamination in the municipal drinking water supply; the latter was subdivided into "early-high" and "late-high" exposure with cut-off at 2005. Incident T2D cases were retrieved from the National Patient Register and the Prescription Register. Cox proportional hazard models with time-varying exposure were used to estimate hazard ratios (HRs). Stratified analyses were performed based on age (18-45 vs > 45). RESULTS Elevated HRs for T2D were observed when comparing "ever-high" to "never-high" exposure (HR 1.18, 95% CI 1.03-1.35), as well as when comparing "early-high" (HR 1.12, 95% CI 0.98-1.50) or "late-high" (HR 1.17, 95% CI 1.00-1.37) to "never-high", after adjusting for age and sex. Individuals aged 18-45 years had even higher HRs. Adjusting for the highest-achieved education level attenuated the estimates, but the directions of associations remained. Elevated HRs were also found among those who had lived in areas with a heavily contaminated water supply for 1-5 years (HR 1.26, 95% CI 0.97-1.63) and 6-10 years (HR 1.25, 95% CI 0.80-1.94). CONCLUSION This study suggests an increased risk of T2D after long-term high PFAS exposure through drinking water. In particular, a higher risk of early onset diabetes was found, indicating increased susceptibility to PFAS-related health effects at younger ages.
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Affiliation(s)
- Yiyi Xu
- School of Public Health and Community Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Kristina Jakobsson
- School of Public Health and Community Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; Occupational and Environmental Medicine, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Florencia Harari
- School of Public Health and Community Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; Occupational and Environmental Medicine, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Eva M Andersson
- School of Public Health and Community Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; Occupational and Environmental Medicine, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Ying Li
- School of Public Health and Community Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; SSORG-Scandinavian Surgical Outcomes Research Group, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
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26
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Wang Y, Howe C, Gallagher LG, Botelho JC, Calafat AM, Karagas MR, Romano ME. Per- and Polyfluoroalkyl Substances (PFAS) Mixture during Pregnancy and Postpartum Weight Retention in the New Hampshire Birth Cohort Study (NHBCS). TOXICS 2023; 11:450. [PMID: 37235264 PMCID: PMC10223499 DOI: 10.3390/toxics11050450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2023] [Revised: 05/01/2023] [Accepted: 05/04/2023] [Indexed: 05/28/2023]
Abstract
Per- and polyfluoroalkyl substances (PFAS), widely used in industrial and consumer products, are suspected metabolic disruptors. We examined the association between a PFAS mixture during pregnancy and postpartum weight retention in 482 participants from the New Hampshire Birth Cohort Study. PFAS concentrations, including perfluorohexane sulfonate, perfluorooctane sulfonate (PFOS), perfluorooctanoate (PFOA), perfluorononanoate (PFNA), and perfluorodecanoate, were quantified in maternal plasma collected at ~28 gestational weeks. Postpartum weight change was calculated as the difference between self-reported weight from a postpartum survey administered in 2020 and pre-pregnancy weight abstracted from medical records. Associations between PFAS and postpartum weight change were examined using Bayesian kernel machine regression and multivariable linear regression, adjusting for demographic, reproductive, dietary, and physical activity factors; gestational week of blood sample collection; and enrollment year. PFOS, PFOA, and PFNA were positively associated with postpartum weight retention, and associations were stronger among participants with a higher pre-pregnancy body mass index. A doubling of PFOS, PFOA, and PFNA concentrations was associated with a 1.76 kg (95%CI: 0.31, 3.22), 1.39 kg (-0.27, 3.04), and 1.04 kg (-0.19, 2.28) greater postpartum weight retention, respectively, among participants who had obesity/overweight prior to pregnancy. Prenatal PFAS exposure may be associated with increased postpartum weight retention.
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Affiliation(s)
- Yuting Wang
- Department of Epidemiology, The Geisel School of Medicine at Dartmouth, Lebanon, NH 03755, USA
| | - Caitlin Howe
- Department of Epidemiology, The Geisel School of Medicine at Dartmouth, Lebanon, NH 03755, USA
| | - Lisa G. Gallagher
- Department of Epidemiology, The Geisel School of Medicine at Dartmouth, Lebanon, NH 03755, USA
| | - Julianne Cook Botelho
- Division of Laboratory Sciences, Centers for Disease Control and Prevention, Atlanta, GA 30341, USA
| | - Antonia M. Calafat
- Division of Laboratory Sciences, Centers for Disease Control and Prevention, Atlanta, GA 30341, USA
| | - Margaret R. Karagas
- Department of Epidemiology, The Geisel School of Medicine at Dartmouth, Lebanon, NH 03755, USA
| | - Megan E. Romano
- Department of Epidemiology, The Geisel School of Medicine at Dartmouth, Lebanon, NH 03755, USA
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27
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Mitro SD, Sundaram R, Buck Louis GM, Peddada S, Chen Z, Kannan K, Gleason JL, Zhang C, Grantz KL. Associations of Pregnancy Per- and Polyfluoroalkyl Substance Concentrations and Uterine Fibroid Changes across Pregnancy: NICHD Fetal Growth Studies - Singletons Cohort. ENVIRONMENTAL HEALTH PERSPECTIVES 2023; 131:57007. [PMID: 37224071 PMCID: PMC10208432 DOI: 10.1289/ehp11606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 04/30/2023] [Accepted: 05/04/2023] [Indexed: 05/26/2023]
Abstract
BACKGROUND Fibroids (hormonally responsive benign tumors) often undergo volume changes in pregnancy. Because per- and polyfluoroalkyl substances (PFAS) disrupt hormonal signaling, they might affect fibroid growth. We assessed associations between PFAS and fibroid changes in pregnancy. METHODS We analyzed seven PFAS, including perfluorohexanesulfonic acid (PFHxS), perfluorooctanesulfonic acid (PFOS), perfluorodecanoic acid (PFDA), and perfluoroundecanoic acid (PFUnDA), in plasma collected at 10-13 wk gestation from 2,621 women in the NICHD Fetal Growth Studies - Singletons cohort (2009-2013). Sonographers recorded fibroid number and volume of the three largest fibroids during up to six timed ultrasounds. Generalized linear models assessed associations of baseline log 2 - transformed PFAS and fibroid number, volume, and presence, and weighted quantile sum regression evaluated the PFAS mixture. Generalized linear mixed models with random intercepts assessed associations of PFAS and longitudinal fibroid number and total volume. Volume analyses were stratified by total volume at first visualization [equivalent to a fibroid < 1 cm (small), 1 to < 3 cm (medium), or ≥ 3 cm (large) in diameter]. RESULTS Fibroid prevalence was 9.4% (n = 245 women). PFAS were not associated with changes in fibroid number, but were associated with volume trajectory, depending on baseline volume. Among women with small volume, PFAS were associated with fibroid growth: Each doubling in PFHxS and PFOS concentrations was associated with 3.6% [95% confidence interval (CI): 0.2, 7.0 and 5.2% (95% CI: - 0.4 , 11.1)] greater weekly fibroid growth, respectively. Among women with medium volume, PFAS were associated with shrinking: Doublings in PFOS, PFDA, and PFUnDA concentrations were associated with 1.9% (95% CI: 0.4, 3.3), 1.2% (95% CI: 0.1, 2.4), and 1.6% (95% CI: 0.4, 2.8) greater weekly fibroid volume reduction, respectively. DISCUSSION Certain PFAS were associated with fibroid growth among women with small fibroids and decreases among women with medium fibroids. PFAS were not associated with fibroid prevalence or number; therefore, PFAS may influence prevalent fibroids rather than initiating fibroid development. https://doi.org/10.1289/EHP11606.
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Affiliation(s)
- Susanna D Mitro
- Division of Population Health Research, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Maryland, USA
| | - Rajeshwari Sundaram
- Division of Population Health Research, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Maryland, USA
| | - Germaine M Buck Louis
- College of Health and Human Services, George Mason University, Fairfax, Virginia, USA
| | - Shyamal Peddada
- Division of Population Health Research, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Maryland, USA
| | - Zhen Chen
- Division of Population Health Research, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Maryland, USA
| | - Kurunthachalam Kannan
- Department of Pediatrics and Department of Environmental Medicine, New York University School of Medicine, New York, New York, USA
| | - Jessica L Gleason
- Division of Population Health Research, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Maryland, USA
| | - Cuilin Zhang
- Division of Population Health Research, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Maryland, USA
- Department of Obstetrics and Gynecology, National University of Singapore Yong Loo Lin School of Medicine, Singapore
| | - Katherine L Grantz
- Division of Population Health Research, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Maryland, USA
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Zhao L, Teng M, Zhao X, Li Y, Sun J, Zhao W, Ruan Y, Leung KMY, Wu F. Insight into the binding model of per- and polyfluoroalkyl substances to proteins and membranes. ENVIRONMENT INTERNATIONAL 2023; 175:107951. [PMID: 37126916 DOI: 10.1016/j.envint.2023.107951] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 04/18/2023] [Accepted: 04/24/2023] [Indexed: 05/03/2023]
Abstract
Legacy per- and polyfluoroalkyl substances (PFASs) have elicited much concern because of their ubiquitous distribution in the environment and the potential hazards they pose to wildlife and human health. Although an increasing number of effective PFAS alternatives are available in the market, these alternatives bring new challenges. This paper comprehensively reviews how PFASs bind to transport proteins (e.g., serum albumin, liver fatty acid transport proteins and organic acid transporters), nuclear receptors (e.g., peroxisome proliferator activated receptors, thyroid hormone receptors and reproductive hormone receptors) and membranes (e.g., cell membrane and mitochondrial membrane). Briefly, the hydrophobic fluorinated carbon chains of PFASs occupy the binding cavities of the target proteins, and the acid groups of PFASs form hydrogen bonds with amino acid residues. Various structural features of PFAS alternatives such as chlorine atom substitution, oxygen atom insertion and a branched structure, introduce variations in their chain length and hydrophobicity, which potentially change the affinity of PFAS alternatives for endogenous proteins. The toxic effects and mechanisms of action of legacy PFASs can be demonstrated and compared with their alternatives using binding models. In future studies, in vitro experiments and in silico quantitative structure-activity relationship modeling should be better integrated to allow more reliable toxicity predictions for both legacy and alternative PFASs.
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Affiliation(s)
- Lihui Zhao
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, China
| | - Miaomiao Teng
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, China.
| | - Xiaoli Zhao
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, China
| | - Yunxia Li
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, China
| | - Jiaqi Sun
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, China
| | - Wentian Zhao
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing, China
| | - Yuefei Ruan
- State Key Laboratory of Marine Pollution and Department of Chemistry, City University of Hong Kong, 999077, Hong Kong Special Administrative Region
| | - Kenneth M Y Leung
- State Key Laboratory of Marine Pollution and Department of Chemistry, City University of Hong Kong, 999077, Hong Kong Special Administrative Region
| | - Fengchang Wu
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, China.
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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: 9] [Impact Index Per Article: 9.0] [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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Carstens KE, Freudenrich T, Wallace K, Choo S, Carpenter A, Smeltz M, Clifton MS, Henderson WM, Richard AM, Patlewicz G, Wetmore BA, Paul Friedman K, Shafer T. Evaluation of Per- and Polyfluoroalkyl Substances (PFAS) In Vitro Toxicity Testing for Developmental Neurotoxicity. Chem Res Toxicol 2023; 36:402-419. [PMID: 36821828 PMCID: PMC10249374 DOI: 10.1021/acs.chemrestox.2c00344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
Per- and polyfluoroalkyl substances (PFAS) are a diverse set of commercial chemicals widely detected in humans and the environment. However, only a limited number of PFAS are associated with epidemiological or experimental data for hazard identification. To provide developmental neurotoxicity (DNT) hazard information, the work herein employed DNT new approach methods (NAMs) to generate in vitro screening data for a set of 160 PFAS. The DNT NAMs battery was comprised of the microelectrode array neuronal network formation assay (NFA) and high-content imaging (HCI) assays to evaluate proliferation, apoptosis, and neurite outgrowth. The majority of PFAS (118/160) were inactive or equivocal in the DNT NAMs, leaving 42 active PFAS that decreased measures of neural network connectivity and neurite length. Analytical quality control indicated 43/118 inactive PFAS samples and 10/42 active PFAS samples were degraded; as such, careful interpretation is required as some negatives may have been due to loss of the parent PFAS, and some actives may have resulted from a mixture of parent and/or degradants of PFAS. PFAS containing a perfluorinated carbon (C) chain length ≥8, a high C:fluorine ratio, or a carboxylic acid moiety were more likely to be bioactive in the DNT NAMs. Of the PFAS positives in DNT NAMs, 85% were also active in other EPA ToxCast assays, whereas 79% of PFAS inactives in the DNT NAMs were active in other assays. These data demonstrate that a subset of PFAS perturb neurodevelopmental processes in vitro and suggest focusing future studies of DNT on PFAS with certain structural feature descriptors.
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Affiliation(s)
- Kelly E Carstens
- Center for Computational Toxicology and Exposure, ORD, US EPA, Research Triangle Park, North Carolina 27711, United States
| | - Theresa Freudenrich
- Center for Computational Toxicology and Exposure, ORD, US EPA, Research Triangle Park, North Carolina 27711, United States
| | - Kathleen Wallace
- Center for Computational Toxicology and Exposure, ORD, US EPA, Research Triangle Park, North Carolina 27711, United States
| | - Seline Choo
- Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, Tennessee 37830, United States
| | - Amy Carpenter
- Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, Tennessee 37830, United States
| | - Marci Smeltz
- Center for Environmental Measurement and Modeling, ORD, US EPA, Research Triangle Park, North Carolina 27711, United States
| | - Matthew S Clifton
- Center for Environmental Measurement and Modeling, ORD, US EPA, Research Triangle Park, North Carolina 27711, United States
| | - W Matthew Henderson
- Center for Environmental Measurement and Modeling, ORD, US EPA, Research Triangle Park, North Carolina 27711, United States
| | - Ann M Richard
- Center for Computational Toxicology and Exposure, ORD, US EPA, Research Triangle Park, North Carolina 27711, United States
| | - Grace Patlewicz
- Center for Computational Toxicology and Exposure, ORD, US EPA, Research Triangle Park, North Carolina 27711, United States
| | - Barbara A Wetmore
- Center for Computational Toxicology and Exposure, ORD, US EPA, Research Triangle Park, North Carolina 27711, United States
| | - Katie Paul Friedman
- Center for Computational Toxicology and Exposure, ORD, US EPA, Research Triangle Park, North Carolina 27711, United States
| | - Timothy Shafer
- Center for Computational Toxicology and Exposure, ORD, US EPA, Research Triangle Park, North Carolina 27711, United States
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Stoker TE, Wang J, Murr AS, Bailey JR, Buckalew AR. High-Throughput Screening of ToxCast PFAS Chemical Library for Potential Inhibitors of the Human Sodium Iodide Symporter. Chem Res Toxicol 2023; 36:380-389. [PMID: 36821091 DOI: 10.1021/acs.chemrestox.2c00339] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
Over the past decade, there has been increased concern for environmental chemicals that can target various sites within the hypothalamic-pituitary-thyroid axis to potentially disrupt thyroid synthesis, transport, metabolism, and/or function. One well-known thyroid target in both humans and wildlife is the sodium iodide symporter (NIS) that regulates iodide uptake into the thyroid gland, the first step of thyroid hormone synthesis. Our laboratory previously developed and validated a radioactive iodide uptake (RAIU) high-throughput assay in a stably transduced human NIS cell line (hNIS-HEK293T-EPA) to identify chemicals with potential for NIS inhibition. So far, we have tested over 2000 chemicals (US EPA's ToxCast chemical libraries PI_v2, PII, and e1K) and discovered a subset of chemicals that significantly inhibit iodide uptake in the hNIS assay. Here, we utilized this screening assay to test a set of 149 unique per- and polyfluoroalkyl substances (PFAS) (ToxCast PFAS library) for potential NIS inhibition. For this evaluation, the 149 blinded samples were screened in a tiered approach, first in an initial single-concentration (≤100 μM) RAIU assay and subsequent evaluation of the chemicals that produced ≥20% inhibition using multiconcentration (MC) response (0.001-100 μM) testing in parallel RAIU and cell viability assays. Of this set, 38 of the PFAS chemicals inhibited iodide uptake ≥20% in the MC testing with 25 displaying inhibition ≥50%. To prioritize the most potent PFAS NIS inhibitors in this set, chemicals were ranked based on outcomes of both iodide uptake and cytotoxicity and normalized to perchlorate, a known positive control. Consistent with previous findings, PFOS and PFHxS were again found to be potent NIS inhibitors, yet significant inhibition was also observed for several other screened PFAS chemicals. Although further studies are clearly warranted, this initial screening effort identifies NIS as a molecular target for potential thyroid disruption by this persistent and structurally diverse class of chemicals.
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Affiliation(s)
- Tammy E Stoker
- Neurotoxicology and Endocrine Toxicology Branch, Public Health and Integrated Toxicology Division, Center of Public Health and Environmental Assessments, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, United States
| | - Jun Wang
- Neurotoxicology and Endocrine Toxicology Branch, Public Health and Integrated Toxicology Division, Center of Public Health and Environmental Assessments, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, United States
- Oak Ridge Institute for Science and Education, US Department of Energy, Oak Ridge, Tennessee 37831, United States
| | - Ashley S Murr
- Neurotoxicology and Endocrine Toxicology Branch, Public Health and Integrated Toxicology Division, Center of Public Health and Environmental Assessments, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, United States
| | - Jarod R Bailey
- Neurotoxicology and Endocrine Toxicology Branch, Public Health and Integrated Toxicology Division, Center of Public Health and Environmental Assessments, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, United States
- Oak Ridge Institute for Science and Education, US Department of Energy, Oak Ridge, Tennessee 37831, United States
| | - Angela R Buckalew
- Neurotoxicology and Endocrine Toxicology Branch, Public Health and Integrated Toxicology Division, Center of Public Health and Environmental Assessments, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, United States
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Wang J, Wang J, Qiu T, Wu J, Sun X, Jiang L, Liu X, Yang G, Cao J, Yao X. Mitochondrial iron overload mediated by cooperative transfer of plasma membrane ATP5B and TFR2 to mitochondria triggers hepatic insulin resistance under PFOS exposure. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2023; 253:114662. [PMID: 36801541 DOI: 10.1016/j.ecoenv.2023.114662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 11/29/2022] [Accepted: 02/14/2023] [Indexed: 06/18/2023]
Abstract
In general populations, insulin resistance (IR) is related to perfluorooctane sulfonate (PFOS), a persistent organic pollutant. However, the underlying mechanism remains unclear. In this study, PFOS induced mitochondrial iron accumulation in the liver of mice and human hepatocytes L-O2. In the PFOS-treated L-O2 cells, mitochondrial iron overload preceded the occurrence of IR, and pharmacological inhibition of mitochondrial iron relieved PFOS-caused IR. Both transferrin receptor 2 (TFR2) and ATP synthase β subunit (ATP5B) were redistributed from the plasma membrane to mitochondria with PFOS treatment. Inhibiting the translocation of TFR2 to mitochondria reversed PFOS-induced mitochondrial iron overload and IR. In the PFOS-treated cells, ATP5B interacted with TFR2. Stabilizing ATP5B on the plasma membrane or knockdown of ATP5B disturbed the translocation of TFR2. PFOS inhibited the activity of plasma-membrane ATP synthase (ectopic ATP synthase, e-ATPS), and activating e-ATPS prevented the translocation of ATP5B and TFR2. Consistently, PFOS induced ATP5B/TFR2 interaction and redistribution of ATP5B and TFR2 to mitochondria in the liver of mice. Thus, our results indicated that mitochondrial iron overload induced by collaborative translocation of ATP5B and TFR2 was an up-stream and initiating event for PFOS-related hepatic IR, providing novel understandings of the biological function of e-ATPS, the regulatory mechanism for mitochondrial iron and the mechanism underlying PFOS toxicity.
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Affiliation(s)
- Jianyu Wang
- Occupational and Environmental Health Department, Dalian Medical University, 9 W Lvshun South Road, Dalian 116044, PR China
| | - Jinling Wang
- Occupational and Environmental Health Department, Dalian Medical University, 9 W Lvshun South Road, Dalian 116044, PR China
| | - Tianming Qiu
- Occupational and Environmental Health Department, Dalian Medical University, 9 W Lvshun South Road, Dalian 116044, PR China
| | - Jialu Wu
- Occupational and Environmental Health Department, Dalian Medical University, 9 W Lvshun South Road, Dalian 116044, PR China
| | - Xiance Sun
- Occupational and Environmental Health Department, Dalian Medical University, 9 W Lvshun South Road, Dalian 116044, PR China
| | - Liping Jiang
- Food Nutrition and Safety Department, Dalian Medical University, 9 W Lvshun South Road, Dalian 116044, PR China
| | - Xiaofang Liu
- Food Nutrition and Safety Department, Dalian Medical University, 9 W Lvshun South Road, Dalian 116044, PR China
| | - Guang Yang
- Food Nutrition and Safety Department, Dalian Medical University, 9 W Lvshun South Road, Dalian 116044, PR China
| | - Jun Cao
- Occupational and Environmental Health Department, Dalian Medical University, 9 W Lvshun South Road, Dalian 116044, PR China
| | - Xiaofeng Yao
- Occupational and Environmental Health Department, Dalian Medical University, 9 W Lvshun South Road, Dalian 116044, PR China.
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Villeneuve DL, Blackwell BR, Cavallin JE, Collins J, Hoang JX, Hofer RN, Houck KA, Jensen KM, Kahl MD, Kutsi RN, Opseth AS, Santana Rodriguez KJ, Schaupp CM, Stacy EH, Ankley GT. Verification of In Vivo Estrogenic Activity for Four Per- and Polyfluoroalkyl Substances (PFAS) Identified as Estrogen Receptor Agonists via New Approach Methodologies. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:3794-3803. [PMID: 36800546 PMCID: PMC10898820 DOI: 10.1021/acs.est.2c09315] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Given concerns about potential toxicological hazards of the thousands of data-poor per- and polyfluorinated alkyl substances (PFAS) currently in commerce and detected in the environment, tiered testing strategies that employ high-throughput in vitro screening as an initial testing tier have been implemented. The present study evaluated the effectiveness of previous in vitro screening for identifying PFAS capable, or incapable, of inducing estrogenic responses in fish exposed in vivo. Fathead minnows (Pimephales promelas) were exposed for 96 h to five PFAS (perfluorooctanoic acid [PFOA]; 1H,1H,8H,8H-perfluorooctane-1,8-diol [FC8-diol]; 1H,1H,10H,10H-perfluorodecane-1,10-diol [FC10-diol]; 1H,1H,8H,8H-perfluoro-3,6-dioxaoctane-1,8-diol [FC8-DOD]; and perfluoro-2-methyl-3-oxahexanoic acid [HFPO-DA]) that showed varying levels of in vitro estrogenic potency. In agreement with in vitro screening results, exposure to FC8-diol, FC10-diol, and FC8-DOD caused concentration-dependent increases in the expression of transcript coding for vitellogenin and estrogen receptor alpha and reduced expression of insulin-like growth factor and apolipoprotein eb. Once differences in bioconcentration were accounted for, the rank order of potency in vivo matched that determined in vitro. These results provide a screening level benchmark for worst-case estimates of potential estrogenic hazards of PFAS and a basis for identifying structurally similar PFAS to scrutinize for putative estrogenic activity.
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Affiliation(s)
- Daniel L. Villeneuve
- US Environmental Protection Agency, Center for Computational Toxicology and Exposure, Great Lakes Toxicology and Ecology Division, Duluth, MN, USA
| | - Brett R. Blackwell
- US Environmental Protection Agency, Center for Computational Toxicology and Exposure, Great Lakes Toxicology and Ecology Division, Duluth, MN, USA
| | - Jenna E. Cavallin
- US Environmental Protection Agency, Center for Computational Toxicology and Exposure, Great Lakes Toxicology and Ecology Division, Duluth, MN, USA
| | - Jacob Collins
- Oak Ridge Institute for Science and Education, US EPA, Great Lakes Toxicology and Ecology Division, Duluth, MN, USA
| | - John X. Hoang
- Oak Ridge Institute for Science and Education, US EPA, Great Lakes Toxicology and Ecology Division, Duluth, MN, USA
| | - Rachel N. Hofer
- Oak Ridge Institute for Science and Education, US EPA, Great Lakes Toxicology and Ecology Division, Duluth, MN, USA
| | - Keith A. Houck
- US Environmental Protection Agency, Center for Computational Toxicology and Exposure, Biomolecular and Computational Toxicology Division, Research Triangle Park, NC, USA
| | - Kathleen M. Jensen
- US Environmental Protection Agency, Center for Computational Toxicology and Exposure, Great Lakes Toxicology and Ecology Division, Duluth, MN, USA
| | - Michael D. Kahl
- US Environmental Protection Agency, Center for Computational Toxicology and Exposure, Great Lakes Toxicology and Ecology Division, Duluth, MN, USA
| | - Robin N. Kutsi
- Oak Ridge Institute for Science and Education, US EPA, Great Lakes Toxicology and Ecology Division, Duluth, MN, USA
| | - Anne S. Opseth
- US Environmental Protection Agency, Center for Computational Toxicology and Exposure, Great Lakes Toxicology and Ecology Division, Duluth, MN, USA
| | - Kelvin J. Santana Rodriguez
- Oak Ridge Institute for Science and Education, US EPA, Great Lakes Toxicology and Ecology Division, Duluth, MN, USA
| | - Christopher M. Schaupp
- Oak Ridge Institute for Science and Education, US EPA, Great Lakes Toxicology and Ecology Division, Duluth, MN, USA
| | - Emma H. Stacy
- Oak Ridge Institute for Science and Education, US EPA, Great Lakes Toxicology and Ecology Division, Duluth, MN, USA
| | - Gerald T. Ankley
- US Environmental Protection Agency, Center for Computational Toxicology and Exposure, Great Lakes Toxicology and Ecology Division, Duluth, MN, USA
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Rehman AU, Crimi M, Andreescu S. Current and emerging analytical techniques for the determination of PFAS in environmental samples. TRENDS IN ENVIRONMENTAL ANALYTICAL CHEMISTRY 2023; 37:e00198. [DOI: 10.1016/j.teac.2023.e00198] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
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Ehrlich V, Bil W, Vandebriel R, Granum B, Luijten M, Lindeman B, Grandjean P, Kaiser AM, Hauzenberger I, Hartmann C, Gundacker C, Uhl M. Consideration of pathways for immunotoxicity of per- and polyfluoroalkyl substances (PFAS). Environ Health 2023; 22:19. [PMID: 36814257 PMCID: PMC9944481 DOI: 10.1186/s12940-022-00958-5] [Citation(s) in RCA: 41] [Impact Index Per Article: 41.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Accepted: 12/30/2022] [Indexed: 05/02/2023]
Abstract
BACKGROUND Per- and polyfluoroalkyl substances (PFAS) are of public health concern, because of their ubiquitous and extremely persistent occurrence, and depending on their structure, their bio-accumulative, mobile and toxic properties. Human health effects associated with exposure to PFAS include adverse effects on the immune system. In 2020, EFSA (the European Food Safety Authority) defined adverse effects on the immune system as the most critical effect for human health risk assessment, based on reduced antibody responses to childhood vaccines and similar effects observed in experimental animal studies. Likewise, the U.S. EPA (Environmental Protection Agency) considers PFAS-induced immunotoxicity, especially in children, as the critical effect for risk assessment. However, the mechanisms by which antibody concentrations are impacted are not completely understood. Furthermore, other targets of the immune system functions have been reported in the literature. OBJECTIVE The aim of this review is to explore PFAS-associated immune-related effects. This includes, relevant mechanisms that may underlie the observed effects on the immune system, immunosuppression as well as immunoenhancement, such as i) modulation of cell signalling and nuclear receptors, such as NF-κB and PPARs; ii) alteration of calcium signalling and homoeostasis in immune cells; iii) modulation of immune cell populations; iv) oxidative stress and v) impact on fatty acid metabolism & secondary effects on the immune system. METHODS A literature research was conducted using three databases (Web of Science, PubMed, and Scopus), which were searched in July 2021 for relevant studies published in the time frame from 2018 to 2021. In total, 487 publications were identified as potentially eligible and following expert-based judgement, articles relevant for mechanisms of PFAS induced immunotoxicity are discussed. CONCLUSIONS Taken together, we show that there is substantial evidence from both in vitro and in vivo experimental as well as epidemiological studies, supporting that various PFAS, not only PFOA and PFOS, affect multiple aspects of the immune system. Timing of exposure is critical, because the developing immune system is especially vulnerable to toxic insults, resulting in a higher risk of particularly adverse immune effects but also other organs later in life.
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Affiliation(s)
- Veronika Ehrlich
- Environment Agency Austria (Umweltbundesamt GmbH), Spittelauer Lände 5, 1090, Vienna, Austria
| | - Wieneke Bil
- Centre for Safety of Substances and Products, National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
| | - Rob Vandebriel
- Centre for Health Protection, National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
| | - Berit Granum
- Division of Climate and Environment Health, Norwegian Institute of Public Health, Oslo, Norway
| | - Mirjam Luijten
- Centre for Health Protection, National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
| | - Birgitte Lindeman
- Division of Climate and Environment Health, Norwegian Institute of Public Health, Oslo, Norway
| | - Philippe Grandjean
- Department of Public Health, University of Southern Denmark, Odense, Denmark
- Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, RI, USA
| | - Andreas-Marius Kaiser
- Environment Agency Austria (Umweltbundesamt GmbH), Spittelauer Lände 5, 1090, Vienna, Austria
| | - Ingrid Hauzenberger
- Environment Agency Austria (Umweltbundesamt GmbH), Spittelauer Lände 5, 1090, Vienna, Austria
| | - Christina Hartmann
- Environment Agency Austria (Umweltbundesamt GmbH), Spittelauer Lände 5, 1090, Vienna, Austria
| | - Claudia Gundacker
- Center for Pathobiochemistry and Genetics, Medical University of Vienna, Vienna, Austria
| | - Maria Uhl
- Environment Agency Austria (Umweltbundesamt GmbH), Spittelauer Lände 5, 1090, Vienna, Austria.
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Smeltz MG, Clifton MS, Henderson WM, McMillan L, Wetmore BA. Targeted Per- and Polyfluoroalkyl substances (PFAS) assessments for high throughput screening: Analytical and testing considerations to inform a PFAS stock quality evaluation framework. Toxicol Appl Pharmacol 2023; 459:116355. [PMID: 36535553 PMCID: PMC10367912 DOI: 10.1016/j.taap.2022.116355] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 11/25/2022] [Accepted: 12/14/2022] [Indexed: 12/23/2022]
Abstract
Per- and polyfluoroalkyl substances (PFAS) represent a large chemical class lacking hazard, toxicokinetic, and exposure information. To accelerate PFAS hazard evaluation, new approach methodologies (NAMs) comprised of in vitro high-throughput toxicity screening, toxicokinetic data, and computational modeling are being employed in read across strategies to evaluate the larger PFAS landscape. A critical consideration to ensure robust evaluations is a parallel assessment of the quality of the screening stock solutions, where dimethyl sulfoxide (DMSO) is often the diluent of choice. Challenged by the lack of commercially available reference standards for many of the selected PFAS and reliance on mass spectrometry approaches for such an evaluation, we developed a high-throughput framework to evaluate the quality of screening stocks for 205 PFAS selected for these NAM efforts. Using mass spectrometry coupled with either liquid or gas chromatography, a quality scoring system was developed that incorporated observations during mass spectral examination to provide a simple pass or fail notation. Informational flags were used to further describe findings regarding parent analyte presence through accurate mass identification, evidence of contaminants and/or degradation, or further describe characteristics such as isomer presence. Across the PFAS-DMSO stocks tested, 148 unique PFAS received passing quality scores to allow for further in vitro testing whereas 57 received a failing score primarily due to detection issues or confounding effects of DMSO. Principle component analysis indicated vapor pressure and Henry's Law Constant as top indicators for a failed quality score for those analyzed by gas chromatography. Three PFAS in the hexafluoropropylene oxide family failed due to degradation in DMSO. As the PFAS evaluated spanned over 20 different structural categories, additional commentary describes analytical observations across specific groups related to PFAS stock composition, detection, stability, and methodologic considerations that will be useful for informing future analytical assessment and downstream HTS efforts. The high-throughput stock quality scoring workflow presented holds value as a tool to evaluate chemical presence and quality efficiently and for informing data inclusion in PFAS or other NAM screening efforts.
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Affiliation(s)
- Marci G Smeltz
- Center for Computational Toxicology and Exposure, Office of Research and Development, United States Environmental Protection Agency, Research Triangle Park, NC 27711, United States of America
| | - M Scott Clifton
- Center for Environmental Measurement and Modeling, Office of Research and Development, United States Environmental Protection Agency, Research Triangle Park, NC 27711, United States of America
| | - W Matthew Henderson
- Center for Environmental Measurement and Modeling, Office of Research and Development, United States Environmental Protection Agency, Athens, GA 23605, United States of America
| | - Larry McMillan
- National Caucus and Center on Black Aged, Inc, Durham, NC, United States of America
| | - Barbara A Wetmore
- Center for Computational Toxicology and Exposure, Office of Research and Development, United States Environmental Protection Agency, Research Triangle Park, NC 27711, United States of America.
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Conley JM, Lambright CS, Evans N, Medlock-Kakaley E, Dixon A, Hill D, McCord J, Strynar MJ, Ford J, Gray LE. Cumulative maternal and neonatal effects of combined exposure to a mixture of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) during pregnancy in the Sprague-Dawley rat. ENVIRONMENT INTERNATIONAL 2022; 170:107631. [PMID: 36402036 PMCID: PMC9944680 DOI: 10.1016/j.envint.2022.107631] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 10/29/2022] [Accepted: 11/10/2022] [Indexed: 05/10/2023]
Abstract
Globally, biomonitoring data demonstrate virtually all humans carry residues of multiple per- and polyfluoroalkyl substances (PFAS). Despite pervasive co-exposure, limited mixtures-based in vivo PFAS toxicity research has been conducted. Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) are commonly detected PFAS in human and environmental samples and both produce adverse effects in laboratory animal studies, including maternal and offspring effects when orally administered during pregnancy and lactation. To evaluate the effects of combined exposure to PFOA and PFOS, we orally exposed pregnant Sprague-Dawley rats from gestation day 8 (GD8) to postnatal day 2 (PND2) to PFOA (10-250 mg/kg/d) or PFOS (0.1-5 mg/kg/d) individually to characterize effects and dose response curve parameters, followed by a variable-ratio mixture experiment with a constant dose of PFOS (2 mg/kg/d) mixed with increasing doses of PFOA (3-80 mg/kg/d). The mixture study design was intended to: 1) shift the PFOA dose response curves for endpoints shared with PFOS, 2) allow comparison of dose addition (DA) and response addition (RA) model predictions, 3) conduct relative potency factor (RPF) analysis for multiple endpoints, and 4) avoid overt maternal toxicity. Maternal serum and liver concentrations of PFOA and PFOS were consistent between the individual chemical and mixture experiments. Combined exposure with PFOS significantly shifted the PFOA dose response curves towards effects at lower doses compared to PFOA-only exposure for multiple endpoints and these effects were well predicted by dose addition. For endpoints amenable to mixture model analyses, DA produced equivalent or better estimates of observed data than RA. All endpoints evaluated were accurately predicted by RPF and DA approaches except for maternal gestational weight gain, which produced less-than-additive results in the mixture. Data support the hypothesis of cumulative effects on shared endpoints from PFOA and PFOS co-exposure and dose additive approaches for predictive estimates of mixture effects.
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Affiliation(s)
- Justin M Conley
- U.S. Environmental Protection Agency/Office of Research & Development/Center for Public Health and Environmental Assessment, Research Triangle Park, NC, USA.
| | - Christy S Lambright
- U.S. Environmental Protection Agency/Office of Research & Development/Center for Public Health and Environmental Assessment, Research Triangle Park, NC, USA.
| | - Nicola Evans
- U.S. Environmental Protection Agency/Office of Research & Development/Center for Public Health and Environmental Assessment, Research Triangle Park, NC, USA.
| | - Elizabeth Medlock-Kakaley
- U.S. Environmental Protection Agency/Office of Research & Development/Center for Public Health and Environmental Assessment, Research Triangle Park, NC, USA.
| | - Aaron Dixon
- U.S. Environmental Protection Agency/Office of Research & Development/Center for Public Health and Environmental Assessment, Research Triangle Park, NC, USA.
| | - Donna Hill
- U.S. Environmental Protection Agency/Office of Research & Development/Center for Public Health and Environmental Assessment, Research Triangle Park, NC, USA.
| | - James McCord
- U.S. Environmental Protection Agency/Office of Research & Development/Center for Environmental Measurement and Modeling, Research Triangle Park, NC, USA.
| | - Mark J Strynar
- U.S. Environmental Protection Agency/Office of Research & Development/Center for Environmental Measurement and Modeling, Research Triangle Park, NC, USA.
| | - Jermaine Ford
- U.S. Environmental Protection Agency/Office of Research & Development/Center for Computational Toxicology and Exposure, Research Triangle Park, NC, USA.
| | - L Earl Gray
- U.S. Environmental Protection Agency/Office of Research & Development/Center for Public Health and Environmental Assessment, Research Triangle Park, NC, USA.
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Yang Z, Roth K, Ding J, Kassotis CD, Mor G, Petriello MC. Exposure to a mixture of per-and polyfluoroalkyl substances modulates pulmonary expression of ACE2 and circulating hormones and cytokines. Toxicol Appl Pharmacol 2022; 456:116284. [PMID: 36270329 PMCID: PMC10325118 DOI: 10.1016/j.taap.2022.116284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 09/29/2022] [Accepted: 10/13/2022] [Indexed: 01/01/2023]
Abstract
Genetic and environmental factors impact on the interindividual variability of susceptibility to communicable and non-communicable diseases. A class of ubiquitous chemicals, Per- and polyfluoroalkyl substances (PFAS) have been linked in epidemiological studies to immunosuppression and increased susceptibility to viral infections, but possible mechanisms are not well elucidated. To begin to gain insight into the role of PFAS in susceptibility to one such viral infection, Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), male and female C57BL/6 J mice were exposed to control water or a mixture of 5 PFAS (PFOS, PFOA, PFNA, PFHxS, Genx) for 12 weeks and lungs were isolated for examination of expression of SARS-CoV-2-related receptors Angiotensin-Converting Enzyme 2 (ACE2) and others. Secondary analyses included circulating hormones and cytokines which have been shown to directly or indirectly impact on ACE2 expression and severity of viral infections. Changes in mRNA and protein expression were analyzed by RT-qPCR and western blotting and circulating hormones and cytokines were determined by ELISA and MESO QuickPlex. The PFAS mixture decreased Ace2 mRNA 2.5-fold in male mice (p < 0.0001), with no significant change observed in females. In addition, TMPRSS2, ANPEP, ENPEP and DPP4 (other genes implicated in COVID-19 infection) were modulated due to PFAS. Plasma testosterone, but not estrogen were strikingly decreased due to PFAS which corresponded to PFAS-mediated repression of 4 representative pulmonary AR target genes; hemoglobin, beta adult major chain (Hbb-b1), Ferrochelatase (Fech), Collagen Type XIV Alpha 1 Chain (Col14a1), 5'-Aminolevulinate Synthase 2 (Alas2). Finally, PFAS modulated circulating pro and anti-inflammatory mediators including IFN-γ (downregulated 3.0-fold in females; p = 0.0301, 2.1-fold in males; p = 0.0418) and IL-6 (upregulated 5.6-fold in males; p = 0.030, no change in females). In conclusion, our data indicate long term exposure to a PFAS mixture impacts mechanisms related to expression of ACE2 in the lung. This work provides a mechanistic rationale for important future studies of PFAS exposure and subsequent viral infection.
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Affiliation(s)
- Zhao Yang
- Institute of Environmental Health Sciences, Wayne State University, Detroit, MI 48202, USA
| | - Katherine Roth
- Institute of Environmental Health Sciences, Wayne State University, Detroit, MI 48202, USA
| | - Jiahui Ding
- C.S Mott Center for Human Growth and Development, Department of Obstetrics and Gynecology, Wayne State University, Detroit, MI 48202, USA
| | - Christopher D Kassotis
- Institute of Environmental Health Sciences, Wayne State University, Detroit, MI 48202, USA; Department of Pharmacology, School of Medicine, Wayne State University, Detroit, MI 48202, USA
| | - Gil Mor
- C.S Mott Center for Human Growth and Development, Department of Obstetrics and Gynecology, Wayne State University, Detroit, MI 48202, USA
| | - Michael C Petriello
- Institute of Environmental Health Sciences, Wayne State University, Detroit, MI 48202, USA; Department of Pharmacology, School of Medicine, Wayne State University, Detroit, MI 48202, USA.
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Patlewicz G, Richard AM, Williams AJ, Judson RS, Thomas RS. Towards reproducible structure-based chemical categories for PFAS to inform and evaluate toxicity and toxicokinetic testing. COMPUTATIONAL TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2022; 24:10.1016/j.comtox.2022.100250. [PMID: 36969381 PMCID: PMC10031514 DOI: 10.1016/j.comtox.2022.100250] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Per- and Polyfluoroalkyl substances (PFAS) are a class of synthetic chemicals that are in widespread use and present concerns for persistence, bioaccumulation and toxicity. Whilst a handful of PFAS have been characterised for their hazard profiles, the vast majority of PFAS have not been studied. The US Environmental Protection Agency (EPA) undertook a research project to screen ~150 PFAS through an array of different in vitro high throughput toxicity and toxicokinetic tests in order to inform chemical category and read-across approaches. A previous publication described the rationale behind the selection of an initial set of 75 PFAS, whereas herein, we describe how various category approaches were applied and extended to inform the selection of a second set of 75 PFAS from our library of approximately 430 commercially procured PFAS. In particular, we focus on the challenges in grouping PFAS for prospective analysis and how we have sought to develop and apply objective structure-based categories to profile the testing library and other PFAS inventories. We additionally illustrate how these categories can be enriched with other information to facilitate read-across inferences once experimental data become available. The availability of flexible, objective, reproducible and chemically intuitive categories to explore PFAS constitutes an important step forward in prioritising PFAS for further testing and assessment.
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Affiliation(s)
- Grace Patlewicz
- Center for Computational Toxicology and Exposure (CCTE), Office of Research and Development, US Environmental Protection Agency, 109 TW Alexander Dr, Research Triangle Park, NC 27711, USA
| | - Ann M. Richard
- Center for Computational Toxicology and Exposure (CCTE), Office of Research and Development, US Environmental Protection Agency, 109 TW Alexander Dr, Research Triangle Park, NC 27711, USA
| | - Antony J. Williams
- Center for Computational Toxicology and Exposure (CCTE), Office of Research and Development, US Environmental Protection Agency, 109 TW Alexander Dr, Research Triangle Park, NC 27711, USA
| | - Richard S. Judson
- Center for Computational Toxicology and Exposure (CCTE), Office of Research and Development, US Environmental Protection Agency, 109 TW Alexander Dr, Research Triangle Park, NC 27711, USA
| | - Russell S. Thomas
- Center for Computational Toxicology and Exposure (CCTE), Office of Research and Development, US Environmental Protection Agency, 109 TW Alexander Dr, Research Triangle Park, NC 27711, USA
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El-Masri H, Paul Friedman K, Isaacs K, Wetmore BA. Advances in computational methods along the exposure to toxicological response paradigm. Toxicol Appl Pharmacol 2022; 450:116141. [PMID: 35777528 PMCID: PMC9619339 DOI: 10.1016/j.taap.2022.116141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 05/27/2022] [Accepted: 06/23/2022] [Indexed: 10/17/2022]
Abstract
Human health risk assessment is a function of chemical toxicity, bioavailability to reach target biological tissues, and potential environmental exposure. These factors are complicated by many physiological, biochemical, physical and lifestyle factors. Furthermore, chemical health risk assessment is challenging in view of the large, and continually increasing, number of chemicals found in the environment. These challenges highlight the need to prioritize resources for the efficient and timely assessment of those environmental chemicals that pose greatest health risks. Computational methods, either predictive or investigative, are designed to assist in this prioritization in view of the lack of cost prohibitive in vivo experimental data. Computational methods provide specific and focused toxicity information using in vitro high throughput screening (HTS) assays. Information from the HTS assays can be converted to in vivo estimates of chemical levels in blood or target tissue, which in turn are converted to in vivo dose estimates that can be compared to exposure levels of the screened chemicals. This manuscript provides a review for the landscape of computational methods developed and used at the U.S. Environmental Protection Agency (EPA) highlighting their potentials and challenges.
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Affiliation(s)
- Hisham El-Masri
- Center for Computational Toxicology and Exposure, Office of Research and Development, U. S. Environmental Protection Agency, Research Triangle Park, NC, USA.
| | - Katie Paul Friedman
- Center for Computational Toxicology and Exposure, Office of Research and Development, U. S. Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Kristin Isaacs
- Center for Computational Toxicology and Exposure, Office of Research and Development, U. S. Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Barbara A Wetmore
- Center for Computational Toxicology and Exposure, Office of Research and Development, U. S. Environmental Protection Agency, Research Triangle Park, NC, USA
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Petersen KU, Hærvig KK, Flachs EM, Bonde JP, Lindh C, Hougaard KS, Toft G, Ramlau-Hansen CH, Tøttenborg SS. Per- and polyfluoroalkyl substances (PFAS) and male reproductive function in young adulthood; a cross-sectional study. ENVIRONMENTAL RESEARCH 2022; 212:113157. [PMID: 35318009 DOI: 10.1016/j.envres.2022.113157] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 03/17/2022] [Accepted: 03/18/2022] [Indexed: 06/14/2023]
Abstract
BACKGROUND Per- and polyfluoroalkyl substances (PFAS) are a large family of persistent industrial chemicals with endocrine disrupting properties. OBJECTIVES To examine biomarkers of reproductive function in young adult males according to current environmental exposure to single and combined PFAS. METHODS The study population consisted of young men (n = 1041, age 18-21) from the Fetal Programming of Semen Quality (FEPOS) cohort. These men were recruited from pregnancies included in the Danish National Birth Cohort (DNBC) between 1996 and 2002. From 2017 to 2019, participants answered an online questionnaire, completed a clinical examination and provided a blood and a semen sample. Exposure to 15 PFAS was measured in plasma. Six compounds were quantified above the limit of detection in at least 80% of the participants. We applied negative binomial regression and weighted quantile sum (WQS) regression models to assess associations between single and combined exposure to PFAS and measures of semen quality, testicular volume and reproductive hormones among the young men. RESULTS We found no consistent associations between plasma concentrations of PFAS, semen quality and testicular volume. Higher levels of single and combined PFAS were associated with slightly higher levels of follicle-stimulating hormone (FSH) (WQS 4% difference, 95% confidence interval: 0, 9). Perfluorooctanoic acid (PFOA) was the main contributor to this finding with positive signals also from perfluorodecanoic acid (PFDA) and perfluorohexane sulfonic acid (PFHxS). DISCUSSION We examined exposure to a range of common PFAS in relation to biomarkers of male reproductive function and found an association with higher levels of FSH among young men from the general population in Denmark. Further studies on especially combined exposure to PFAS are needed to expand our understanding of potential endocrine disruption from both legacy and emerging compounds in relation to male reproductive function.
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Affiliation(s)
- Kajsa Ugelvig Petersen
- Department of Occupational and Environmental Medicine, Copenhagen University Hospital - Bispebjerg and Frederiksberg, Copenhagen, Denmark.
| | - Katia Keglberg Hærvig
- Department of Occupational and Environmental Medicine, Copenhagen University Hospital - Bispebjerg and Frederiksberg, Copenhagen, Denmark
| | - Esben Meulengracht Flachs
- Department of Occupational and Environmental Medicine, Copenhagen University Hospital - Bispebjerg and Frederiksberg, Copenhagen, Denmark
| | - Jens Peter Bonde
- Department of Occupational and Environmental Medicine, Copenhagen University Hospital - Bispebjerg and Frederiksberg, Copenhagen, Denmark; Department of Public Health, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Christian Lindh
- Division of Occupational and Environmental Medicine, Lund University, Lund, Sweden
| | - Karin Sørig Hougaard
- Department of Public Health, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; National Research Centre for the Working Environment, Copenhagen, Denmark
| | - Gunnar Toft
- Steno Diabetes Center Aarhus, Aarhus University Hospital, Aarhus, Denmark
| | | | - Sandra Søgaard Tøttenborg
- Department of Occupational and Environmental Medicine, Copenhagen University Hospital - Bispebjerg and Frederiksberg, Copenhagen, Denmark; Department of Public Health, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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Evans N, Conley JM, Cardon M, Hartig P, Medlock-Kakaley E, Gray LE. In vitro activity of a panel of per- and polyfluoroalkyl substances (PFAS), fatty acids, and pharmaceuticals in peroxisome proliferator-activated receptor (PPAR) alpha, PPAR gamma, and estrogen receptor assays. Toxicol Appl Pharmacol 2022; 449:116136. [PMID: 35752307 PMCID: PMC9341220 DOI: 10.1016/j.taap.2022.116136] [Citation(s) in RCA: 41] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 06/03/2022] [Accepted: 06/16/2022] [Indexed: 10/17/2022]
Abstract
Data demonstrate numerous per- and polyfluoroalkyl substances (PFAS) activate peroxisome proliferator-activated receptor alpha (PPARα), however, additional work is needed to characterize PFAS activity on PPAR gamma (PPARγ) and other nuclear receptors. We utilized in vitro assays with either human or rat PPARα or PPARγ ligand binding domains to evaluate 16 PFAS (HFPO-DA, HFPO-DA-AS, NBP2, PFMOAA, PFHxA, PFOA, PFNA, PFDA, PFOS, PFBS, PFHxS, PFOSA, EtPFOSA, and 4:2, 6:2 and 8:2 FTOH), 3 endogenous fatty acids (oleic, linoleic, and octanoic), and 3 pharmaceuticals (WY14643, clofibrate, and the metabolite clofibric acid). We also tested chemicals for human estrogen receptor (hER) transcriptional activation. Nearly all compounds activated both PPARα and PPARγ in both human and rat ligand binding domain assays, except for the FTOH compounds and PFOSA. Receptor activation and relative potencies were evaluated based on effect concentration 20% (EC20), top percent of max fold induction (pmaxtop), and area under the curve (AUC). HFPO-DA and HFPO-DA-AS were the most potent (lowest EC20, highest pmaxtop and AUC) of all PFAS in rat and human PPARα assays, being slightly less potent than oleic and linoleic acid, while NBP2 was the most potent in rat and human PPARγ assays. Only PFHxS, 8:2 and 6:2 FTOH exhibited hER agonism >20% pmax. In vitro measures of human and rat PPARα and PPARγ activity did not correlate with oral doses or serum concentrations of PFAS that induced increases in male rat liver weight from the National Toxicology Program 28-d toxicity studies. Data indicate that both PPARα and PPARγ activation may be molecular initiating events that contribute to the in vivo effects observed for many PFAS.
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Affiliation(s)
- Nicola Evans
- U.S. Environmental Protection Agency/Office of Research & Development/Center for Public Health and Environmental Assessment/Public Health and Integrated Toxicology Division, Research Triangle Park, NC 27711, USA.
| | - Justin M Conley
- U.S. Environmental Protection Agency/Office of Research & Development/Center for Public Health and Environmental Assessment/Public Health and Integrated Toxicology Division, Research Triangle Park, NC 27711, USA.
| | - Mary Cardon
- U.S. Environmental Protection Agency/Office of Research & Development/Center for Public Health and Environmental Assessment/Public Health and Integrated Toxicology Division, Research Triangle Park, NC 27711, USA.
| | - Phillip Hartig
- U.S. Environmental Protection Agency/Office of Research & Development/Center for Public Health and Environmental Assessment/Public Health and Integrated Toxicology Division, Research Triangle Park, NC 27711, USA.
| | - Elizabeth Medlock-Kakaley
- U.S. Environmental Protection Agency/Office of Research & Development/Center for Public Health and Environmental Assessment/Public Health and Integrated Toxicology Division, Research Triangle Park, NC 27711, USA.
| | - L Earl Gray
- U.S. Environmental Protection Agency/Office of Research & Development/Center for Public Health and Environmental Assessment/Public Health and Integrated Toxicology Division, Research Triangle Park, NC 27711, USA.
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Ward-Caviness CK, Moyer J, Weaver A, Devlin R, Diaz-Sanchez D. Associations between PFAS occurrence and multimorbidity as observed in an electronic health record cohort. Environ Epidemiol 2022; 6:e217. [PMID: 35975166 PMCID: PMC9374186 DOI: 10.1097/ee9.0000000000000217] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 06/14/2022] [Indexed: 01/06/2023] Open
Abstract
Per and polyfluoroalkyl substances (PFAS) are associated with health outcomes ranging from cancer to high cholesterol. However, there has been little examination of how PFAS exposure might impact the development of multiple chronic diseases, known as multimorbidity. Here, we associated the presence of one or more PFAS in water systems serving the zip code of residence with chronic disease and multimorbidity.
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Grouping of PFAS for human health risk assessment: Findings from an independent panel of experts. Regul Toxicol Pharmacol 2022; 134:105226. [PMID: 35817206 DOI: 10.1016/j.yrtph.2022.105226] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 06/07/2022] [Accepted: 07/06/2022] [Indexed: 01/09/2023]
Abstract
An expert panel was convened to provide insight and guidance on per- and polyfluoroalkyl substances (PFAS) grouping for the purposes of protecting human health from drinking water exposures, and how risks to PFAS mixtures should be assessed. These questions were addressed through multiple rounds of blind, independent responses to charge questions, and review and comments on co-panelists responses. The experts agreed that the lack of consistent interpretations of human health risk for well-studied PFAS and the lack of information for the vast majority of PFAS present significant challenges for any mixtures risk assessment approach. Most experts agreed that "all PFAS" should not be grouped together, persistence alone is not sufficient for grouping PFAS for the purposes of assessing human health risk, and that the definition of appropriate subgroups can only be defined on a case-by-case manner. Most panelists agreed that it is inappropriate to assume equal toxicity/potency across the diverse class of PFAS. A tiered approach combining multiple lines of evidence was presented as a possible viable means for addressing PFAS that lack analytical and/or toxicological studies. Most PFAS risk assessments will need to employ assumptions that are more likely to overestimate risk than to underestimate risk, given the choice of assumptions regarding dose-response model, uncertainty factors, and exposure information.
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Dong Z, Wang J, Qiu T, Wu J, An Y, Shi X, Sun X, Jiang L, Liu X, Yang G, Cao J, Yao X. Perfluorooctane sulfonate induces mitochondrial calcium overload and early hepatic insulin resistance via autophagy/detyrosinated alpha-tubulin-regulated IP3R2-VDAC1-MICU1 interaction. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 825:153933. [PMID: 35192817 DOI: 10.1016/j.scitotenv.2022.153933] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 02/11/2022] [Accepted: 02/12/2022] [Indexed: 06/14/2023]
Abstract
Perfluorooctane sulfonate (PFOS), one kind of persistent organic pollutants, is associated with insulin resistance (IR) in general population. However, the exact mechanism is still obscure. In this study, we found that 50 μM PFOS caused IR in L-02 hepatocytes after 1 h, and induced autophagy and mitochondrial calcium (Ca2+) accumulation as early as 0.5 h. Inhibiting autophagy relieved mitochondrial Ca2+ overload and then reversed IR. Mitochondria were aggregated at cell periphery, and extracellular Ca2+ from IP3R2 on the plasma membrane, rather than endoplasmic reticulum Ca2+, was the priority source of mitochondrial Ca2+ uptake at early stages of PFOS exposure. Furthermore, we discovered that the linkage connecting autophagy and mitochondrial Ca2+ response was detyrosinated α-tubulin, which autophagy-dependently ascended, interacted with VDAC1 and enhanced the formation of IP3R2-VDAC1-MICU1 complex. Consistently, PFOS caused IR, activated autophagy, induced mitochondrial Ca2+ overload, increased the level of detyrosinated α-tubulin, and promoted the formation of IP3R2-VDAC1-MICU1 complex in the liver of C57BL/6J mice exposed to 2.5 mg/kg/day PFOS for 6 weeks. This study clarified that autophagy and mitochondrial Ca2+ accumulation were the early and triggering event that caused PFOS-related IR, also unveiled a novel mechanism regulating mitochondrial Ca2+ homeostasis.
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Affiliation(s)
- Zhanchen Dong
- Department of Occupational and Environmental Health, Dalian Medical University, 9 W Lushun South Road, Dalian 116044, PR China
| | - Jianyu Wang
- Department of Occupational and Environmental Health, Dalian Medical University, 9 W Lushun South Road, Dalian 116044, PR China
| | - Tianming Qiu
- Department of Occupational and Environmental Health, Dalian Medical University, 9 W Lushun South Road, Dalian 116044, PR China
| | - Jialu Wu
- Department of Occupational and Environmental Health, Dalian Medical University, 9 W Lushun South Road, Dalian 116044, PR China
| | - Yu An
- Dalian Municipal Center for Disease Control and Prevention, 151 Yueling West Street, Ganjingzi District, Dalian 116037, PR China
| | - Xiaoxia Shi
- Department of Occupational and Environmental Health, Dalian Medical University, 9 W Lushun South Road, Dalian 116044, PR China
| | - Xiance Sun
- Department of Occupational and Environmental Health, Dalian Medical University, 9 W Lushun South Road, Dalian 116044, PR China
| | - Liping Jiang
- Department of Food Nutrition and Safety, Dalian Medical University, 9 W Lushun South Road, Dalian 116044, PR China
| | - Xiaofang Liu
- Department of Food Nutrition and Safety, Dalian Medical University, 9 W Lushun South Road, Dalian 116044, PR China
| | - Guang Yang
- Department of Food Nutrition and Safety, Dalian Medical University, 9 W Lushun South Road, Dalian 116044, PR China
| | - Jun Cao
- Department of Occupational and Environmental Health, Dalian Medical University, 9 W Lushun South Road, Dalian 116044, PR China
| | - Xiaofeng Yao
- Department of Occupational and Environmental Health, Dalian Medical University, 9 W Lushun South Road, Dalian 116044, PR China.
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Truong L, Rericha Y, Thunga P, Marvel S, Wallis D, Simonich MT, Field JA, Cao D, Reif DM, Tanguay RL. Systematic developmental toxicity assessment of a structurally diverse library of PFAS in zebrafish. JOURNAL OF HAZARDOUS MATERIALS 2022; 431:128615. [PMID: 35263707 PMCID: PMC8970529 DOI: 10.1016/j.jhazmat.2022.128615] [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] [Received: 01/08/2022] [Revised: 02/20/2022] [Accepted: 02/28/2022] [Indexed: 06/03/2023]
Abstract
Per- and polyfluoroalkyl substances (PFAS) are a class of widely used chemicals with limited human health effects data relative to the diversity of structures manufactured. To help fill this data gap, an extensive in vivo developmental toxicity screen was performed on 139 PFAS provided by the US EPA. Dechorionated embryonic zebrafish were exposed to 10 nominal water concentrations of PFAS (0.015-100 µM) from 6 to 120 h post-fertilization (hpf). The embryos were assayed for embryonic photomotor response (EPR), larval photomotor response (LPR), and 13 morphological endpoints. A total of 49 PFAS (35%) were bioactive in one or more assays (11 altered EPR, 25 altered LPR, and 31 altered morphology). Perfluorooctanesulfonamide (FOSA) was the only structure that was bioactive in all 3 assays, while Perfluorodecanoic acid (PFDA) was the most potent teratogen. Low PFAS volatility was associated with developmental toxicity (p < 0.01), but no association was detected between bioactivity and five other physicochemical parameters. The bioactive PFAS were enriched for 6 supergroup chemotypes. The results illustrate the power of a multi-dimensional in vivo platform to assess the developmental (neuro)toxicity of diverse PFAS and in the acceleration of PFAS safety research.
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Affiliation(s)
- Lisa Truong
- Department of Environmental and Molecular Toxicology, the Sinnhuber Aquatic Research Laboratory, and the Environmental Health Sciences Center at Oregon State University, Corvallis, OR, USA
| | - Yvonne Rericha
- Department of Environmental and Molecular Toxicology, the Sinnhuber Aquatic Research Laboratory, and the Environmental Health Sciences Center at Oregon State University, Corvallis, OR, USA
| | - Preethi Thunga
- Bioinformatics Research Center, Department of Biological Sciences, North Carolina State University, Raleigh, NC, USA
| | - Skylar Marvel
- Bioinformatics Research Center, Department of Biological Sciences, North Carolina State University, Raleigh, NC, USA
| | - Dylan Wallis
- Bioinformatics Research Center, Department of Biological Sciences, North Carolina State University, Raleigh, NC, USA
| | - Michael T Simonich
- Department of Environmental and Molecular Toxicology, the Sinnhuber Aquatic Research Laboratory, and the Environmental Health Sciences Center at Oregon State University, Corvallis, OR, USA
| | - Jennifer A Field
- Department of Environmental and Molecular Toxicology, Department of Chemistry at Oregon State University, Corvallis, OR, USA
| | - Dunping Cao
- Department of Environmental and Molecular Toxicology, Department of Chemistry at Oregon State University, Corvallis, OR, USA
| | - David M Reif
- Bioinformatics Research Center, Department of Biological Sciences, North Carolina State University, Raleigh, NC, USA
| | - Robyn L Tanguay
- Bioinformatics Research Center, Department of Biological Sciences, North Carolina State University, Raleigh, NC, USA.
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47
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Wang R, Lin ZW, Klemes MJ, Ateia M, Trang B, Wang J, Ching C, Helbling DE, Dichtel WR. A Tunable Porous β-Cyclodextrin Polymer Platform to Understand and Improve Anionic PFAS Removal. ACS CENTRAL SCIENCE 2022; 8:663-669. [PMID: 35647288 PMCID: PMC9136966 DOI: 10.1021/acscentsci.2c00478] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Indexed: 05/26/2023]
Abstract
Cross-linked polymers containing β-cyclodextrin (β-CD) are promising adsorbents with demonstrated removal performances for per- and polyfluoroalkyl substances (PFASs) from contaminated water sources. Despite the promising performance of some β-CD-based adsorbents for PFAS removal, many of these materials are not amenable for rational performance improvement or addressing fundamental questions about the PFAS adsorption mechanisms. These ambiguities arise from the poorly defined structure of the cross-linked polymers, especially with respect to the random substitution patterns of the cyclodextrins as well as side reactions that modify the structures of some cross-linkers. Here, we report a new β-CD polymer platform in which styrene groups are covalently attached to β-CD to form a discrete monomer that is amenable to radical polymerization. This monomer was polymerized with styrene and methacrylate comonomers to provide three β-CD polymers with high specific surface areas and high isolated yields (all >93%). A β-CD polymer copolymerized with a methacrylate bearing a cationic functional group achieved nearly 100% removal for eight anionic PFASs (initial concentration of 1 μg/L for each compound) in nanopure water at an exceedingly low adsorbent loading of 1 mg L-1, as compared to previous cyclodextrin polymers that required loadings at least 1 order of magnitude higher to achieve an equivalent degree of PFAS removal. Furthermore, when the adsorbents were studied in a challenging salt matrix, we observed that long-chain PFAS adsorption was controlled by a complementary interplay of hydrophobic and electrostatic interactions, whereas short-chain PFASs primarily relied on electrostatic interactions. This approach demonstrates great promise for anionic PFAS removal, and we anticipate that new compositions will be tailored using the versatility of radical polymerization to simultaneously target PFASs and other classes of micropollutants in the future.
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Affiliation(s)
- Ri Wang
- School
of Civil and Environmental Engineering, Cornell University, Ithaca, New York 14853, United States
| | - Zhi-Wei Lin
- Department
of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Max J. Klemes
- Department
of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Mohamed Ateia
- Department
of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Brittany Trang
- Department
of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Jieyuan Wang
- School
of Civil and Environmental Engineering, Cornell University, Ithaca, New York 14853, United States
| | - Casey Ching
- School
of Civil and Environmental Engineering, Cornell University, Ithaca, New York 14853, United States
| | - Damian E. Helbling
- School
of Civil and Environmental Engineering, Cornell University, Ithaca, New York 14853, United States
| | - William R. Dichtel
- Department
of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
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48
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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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49
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Carlson LM, Angrish M, Shirke AV, Radke EG, Schulz B, Kraft A, Judson R, Patlewicz G, Blain R, Lin C, Vetter N, Lemeris C, Hartman P, Hubbard H, Arzuaga X, Davis A, Dishaw LV, Druwe IL, Hollinger H, Jones R, Kaiser JP, Lizarraga L, Noyes PD, Taylor M, Shapiro AJ, Williams AJ, Thayer KA. Systematic Evidence Map for Over One Hundred and Fifty Per- and Polyfluoroalkyl Substances (PFAS). ENVIRONMENTAL HEALTH PERSPECTIVES 2022; 130:56001. [PMID: 35580034 PMCID: PMC9113544 DOI: 10.1289/ehp10343] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 03/28/2022] [Accepted: 03/29/2022] [Indexed: 05/05/2023]
Abstract
BACKGROUND Per- and polyfluoroalkyl substances (PFAS) are a large class of synthetic (man-made) chemicals widely used in consumer products and industrial processes. Thousands of distinct PFAS exist in commerce. The 2019 U.S. Environmental Protection Agency (U.S. EPA) Per- and Polyfluoroalkyl Substances (PFAS) Action Plan outlines a multiprogram national research plan to address the challenge of PFAS. One component of this strategy involves the use of systematic evidence map (SEM) approaches to characterize the evidence base for hundreds of PFAS. OBJECTIVE SEM methods were used to summarize available epidemiological and animal bioassay evidence for a set of ∼ 150 PFAS that were prioritized in 2019 by the U.S. EPA's Center for Computational Toxicology and Exposure (CCTE) for in vitro toxicity and toxicokinetic assay testing. METHODS Systematic review methods were used to identify and screen literature using manual review and machine-learning software. The Populations, Exposures, Comparators, and Outcomes (PECO) criteria were kept broad to identify mammalian animal bioassay and epidemiological studies that could inform human hazard identification. A variety of supplemental content was also tracked, including information on in vitro model systems; exposure measurement-only studies in humans; and absorption, distribution, metabolism, and excretion (ADME). Animal bioassay and epidemiology studies meeting PECO criteria were summarized with respect to study design, and health system(s) were assessed. Because animal bioassay studies with ≥ 21 -d exposure duration (or reproductive/developmental study design) were most useful to CCTE analyses, these studies underwent study evaluation and detailed data extraction. All data extraction is publicly available online as interactive visuals with downloadable metadata. RESULTS More than 40,000 studies were identified from scientific databases. Screening processes identified 44 animal and 148 epidemiology studies from the peer-reviewed literature and 95 animal and 50 epidemiology studies from gray literature that met PECO criteria. Epidemiological evidence (available for 15 PFAS) mostly assessed the reproductive, endocrine, developmental, metabolic, cardiovascular, and immune systems. Animal evidence (available for 40 PFAS) commonly assessed effects in the reproductive, developmental, urinary, immunological, and hepatic systems. Overall, 45 PFAS had evidence across animal and epidemiology data streams. DISCUSSION Many of the ∼ 150 PFAS were data poor. Epidemiological and animal evidence were lacking for most of the PFAS included in our search. By disseminating this information, we hope to facilitate additional assessment work by providing the initial scoping literature survey and identifying key research needs. Future research on data-poor PFAS will help support a more complete understanding of the potential health effects from PFAS exposures. https://doi.org/10.1289/EHP10343.
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Affiliation(s)
- Laura M Carlson
- Center for Public Health and Environmental Assessment, Health & Environmental Effects Assessment Division (HEEAD), U.S. Environmental Protection Agency (U.S. EPA), Durham, North Carolina, USA
| | - Michelle Angrish
- Center for Public Health and Environmental Assessment, Chemical & Pollutant Assessment Division (CPAD), U.S. EPA, Durham, North Carolina, USA
| | - Avanti V Shirke
- Center for Public Health and Environmental Assessment, Chemical & Pollutant Assessment Division (CPAD), U.S. EPA, Washington, District of Columbia, USA
| | - Elizabeth G Radke
- Center for Public Health and Environmental Assessment, Chemical & Pollutant Assessment Division (CPAD), U.S. EPA, Washington, District of Columbia, USA
| | - Brittany Schulz
- Oak Ridge Associated Universities (ORAU), Oak Ridge, Tennessee, USA
| | - Andrew Kraft
- Center for Public Health and Environmental Assessment, Chemical & Pollutant Assessment Division (CPAD), U.S. EPA, Washington, District of Columbia, USA
| | - Richard Judson
- Center for Computational Toxicology and Exposure (CCTE), U.S. EPA, Durham, North Carolina, USA
| | - Grace Patlewicz
- Center for Computational Toxicology and Exposure (CCTE), U.S. EPA, Durham, North Carolina, USA
| | | | | | | | | | | | | | - Xabier Arzuaga
- Center for Public Health and Environmental Assessment, Chemical & Pollutant Assessment Division (CPAD), U.S. EPA, Washington, District of Columbia, USA
| | - Allen Davis
- Center for Public Health and Environmental Assessment, Chemical & Pollutant Assessment Division (CPAD), U.S. EPA, Washington, District of Columbia, USA
| | - Laura V Dishaw
- Center for Public Health and Environmental Assessment, Chemical & Pollutant Assessment Division (CPAD), U.S. EPA, Durham, North Carolina, USA
| | - Ingrid L Druwe
- Center for Public Health and Environmental Assessment, Chemical & Pollutant Assessment Division (CPAD), U.S. EPA, Durham, North Carolina, USA
| | - Hillary Hollinger
- Center for Public Health and Environmental Assessment, Health & Environmental Effects Assessment Division (HEEAD), U.S. Environmental Protection Agency (U.S. EPA), Durham, North Carolina, USA
| | - Ryan Jones
- Center for Public Health and Environmental Assessment, Health & Environmental Effects Assessment Division (HEEAD), U.S. Environmental Protection Agency (U.S. EPA), Durham, North Carolina, USA
| | - J Phillip Kaiser
- Center for Public Health and Environmental Assessment, Chemical & Pollutant Assessment Division (CPAD), U.S. EPA, Cincinnati, Ohio, USA
| | - Lucina Lizarraga
- Center for Public Health and Environmental Assessment, Chemical & Pollutant Assessment Division (CPAD), U.S. EPA, Cincinnati, Ohio, USA
| | - Pamela D Noyes
- Center for Public Health and Environmental Assessment, Chemical & Pollutant Assessment Division (CPAD), U.S. EPA, Washington, District of Columbia, USA
| | - Michele Taylor
- Center for Public Health and Environmental Assessment, Chemical & Pollutant Assessment Division (CPAD), U.S. EPA, Durham, North Carolina, USA
| | - Andrew J Shapiro
- Center for Public Health and Environmental Assessment, Health & Environmental Effects Assessment Division (HEEAD), U.S. Environmental Protection Agency (U.S. EPA), Durham, North Carolina, USA
| | - Antony J Williams
- Center for Computational Toxicology and Exposure (CCTE), U.S. EPA, Durham, North Carolina, USA
| | - Kristina A Thayer
- Center for Public Health and Environmental Assessment, Chemical & Pollutant Assessment Division (CPAD), U.S. EPA, Durham, North Carolina, USA
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50
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Wang YQ, Hu LX, Liu T, Zhao JH, Yang YY, Liu YS, Ying GG. Per- and polyfluoralkyl substances (PFAS) in drinking water system: Target and non-target screening and removal assessment. ENVIRONMENT INTERNATIONAL 2022; 163:107219. [PMID: 35405506 DOI: 10.1016/j.envint.2022.107219] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 03/25/2022] [Accepted: 03/26/2022] [Indexed: 06/14/2023]
Abstract
The massive use and the persistence of per- and polyfluoroalkyl substances (PFAS) have led to their frequent detection in aquatic environments, which may further threaten drinking water safety. So far, our knowledge about the occurrence of PFAS in drinking water system is still very limited. Here we investigated the occurrence and removal of PFAS in a drinking water system using non-target, suspect and target screening strategies. Sampling was performed in three seasons in the drinking water system including a water source, two drinking water treatment plants, and tap water in five households. The results showed detection of 17 homologous series with 51 homologues in non-target screening and 50 potential PFAS detected in suspect screening. Probable structures were proposed for 15 PFAS with high confidence levels (the first three of the five levels), with seven of them being reported for the first time in drinking water system. Semi-quantification was performed on seven homologous series based on target PFAS, the estimated total concentrations for non-target PFAS ranged between 4.10 and 17.6 ng/L. Nine out of 50 target PFAS were found and precisely quantified (<LOQ-13.4 ng/L) with predominance of perfluorocarboxylic acids (PFCA) and perfluorosulfonic acids (PFSA). All target and non-target PFAS were detected in tap water with similar concentrations in all three seasons. Removal efficiency for the detected PFAS in each processing unit was almost zero, indicating the recalcitrance of these chemicals to the conventional treatment process. The findings from this study clearly show the wide presence of PFAS in the whole drinking water treatment process, and suggest an urgent need for effective removal technology for this group of chemicals.
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Affiliation(s)
- Yu-Qing Wang
- SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou 510006, China; School of Environment, South China Normal University, University Town, Guangzhou 510006, China
| | - Li-Xin Hu
- SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou 510006, China; School of Environment, South China Normal University, University Town, Guangzhou 510006, China.
| | - Ting Liu
- SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou 510006, China; School of Environment, South China Normal University, University Town, Guangzhou 510006, China
| | - Jia-Hui Zhao
- SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou 510006, China; School of Environment, South China Normal University, University Town, Guangzhou 510006, China
| | - Yuan-Yuan Yang
- SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou 510006, China; School of Environment, South China Normal University, University Town, Guangzhou 510006, China
| | - You-Sheng Liu
- SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou 510006, China; School of Environment, South China Normal University, University Town, Guangzhou 510006, China
| | - Guang-Guo Ying
- SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou 510006, China; School of Environment, South China Normal University, University Town, Guangzhou 510006, China.
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