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Zeidabadi FA, Esfahani EB, McBeath ST, Mohseni M. Managing PFAS exhausted Ion-exchange resins through effective regeneration/electrochemical process. Water Res 2024; 255:121529. [PMID: 38554630 DOI: 10.1016/j.watres.2024.121529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 03/03/2024] [Accepted: 03/25/2024] [Indexed: 04/02/2024]
Abstract
This study proposes an integrated approach that combines ion-exchange (IX) and electrochemical technologies to tackle problems associated with PFAS contamination. Our investigation centers on evaluating the recovery and efficiency of IX/electrochemical systems in the presence of five different salts, spanning dosages from 0.1 % to 8 %. The outcomes reveal a slight superiority for NaCl within the regeneration system, with sulfate and bicarbonate also showing comparable efficacy. Notably, the introduction of chloride ion (Cl-) into the electrochemical system results in substantial generation of undesirable chlorate (ClO3-) and perchlorate (ClO4-) by-products, accounting for ∼18 % and ∼81 % of the consumed Cl-, respectively. Several agents, including H2O2, KI, and Na2S2O3, exhibited effective mitigation of ClO3- and ClO4- formation. However, only H2O2 demonstrated a favorable influence on the degradation and defluorination of PFOA. The addition of 0.8 M H2O2 resulted in the near-complete removal of ClO3- and ClO4-, accompanied by 1.3 and 2.2-fold enhancements in the degradation and defluorination of PFOA, respectively. Furthermore, a comparative analysis of different salts in the electrochemical system reveals that Cl- and OH- ions exhibit slower performance, possibly due to competitive interactions with PFOA on the anode's reactive sites. In contrast, sulfate and bicarbonate salts consistently demonstrate robust decomposition efficiencies. Despite the notable enhancement in IX regeneration efficacy facilitated by the presence of methanol, particularly for PFAS-specific resins, this enhancement comes at the cost of reduced electrochemical decomposition of all PFAS. The average decay rate ratio of all PFAS in the presence of 50 % methanol, compared to its absence, falls within the range of 0.11-0.39. In conclusion, the use of 1 % Na2SO4 salt stands out as a favorable option for the integrated IX/electrochemical process. This choice not only eliminates the need to introduce an additional chemical (e.g., H2O2) into the wastewater stream, but also ensures both satisfactory regeneration recovery and efficiency in the decomposition process through electrochemical treatment.
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Affiliation(s)
- Fatemeh Asadi Zeidabadi
- Department of Chemical and Biological Engineering, University of British Columbia, 2360 East Mall, Vancouver, Canada
| | - Ehsan Banayan Esfahani
- Department of Chemical and Biological Engineering, University of British Columbia, 2360 East Mall, Vancouver, Canada
| | - Sean T McBeath
- Department of Civil and Environmental Engineering, University of Massachusetts Amherst, Amherst, MA 01003, United States
| | - Madjid Mohseni
- Department of Chemical and Biological Engineering, University of British Columbia, 2360 East Mall, Vancouver, Canada.
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2
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Dunn F, Paquette SE, Pennell KD, Plavicki JS, Manz KE. Metabolomic changes following GenX and PFBS exposure in developing zebrafish. Aquat Toxicol 2024; 271:106908. [PMID: 38608566 DOI: 10.1016/j.aquatox.2024.106908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2024] [Revised: 03/30/2024] [Accepted: 04/02/2024] [Indexed: 04/14/2024]
Abstract
Short chain per- and polyfluoroalkyl substances (PFAS), including hexafluoropropylene oxide dimer acid (GenX) and perfluorobutane sulfonate (PFBS), are replacement chemicals for environmentally persistent, long-chain PFAS. Although GenX and PFBS have been detected in surface and ground water worldwide, few studies provide information on the metabolic alterations or risks associated with their exposures. In this study, larval zebrafish were used to investigate the toxicity of early-life exposure to GenX or PFBS. Zebrafish were chronically exposed from 4 h post-fertilization (hpf) to 6 days post-fertilization (dpf) to 150 µM GenX or 95.0 µM PFBS. Ultra-high-performance liquid chromatography paired with high-resolution mass spectrometry was used to quantify uptake of GenX and PFBS into zebrafish larvae and perform targeted and untargeted metabolomics. Our results indicate that PFBS was 20.4 % more readily absorbed into the zebrafish larvae compared to GenX. Additionally, PFBS exposure significantly altered 13 targeted metabolites and 21 metabolic pathways, while GenX exposure significantly altered 1 targeted metabolite and 17 metabolic pathways. Exposure to GenX, and to an even greater extent PFBS, resulted in a number of altered metabolic pathways in the amino acid metabolism, with other significant alterations in the carbohydrate, lipid, cofactors and vitamins, nucleotide, and xenobiotics metabolisms. Our results indicate that GenX and PFBS impact the zebrafish metabolome, with implications of global metabolic dysregulation, particularly in metabolic pathways relating to growth and development.
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Affiliation(s)
- Fiona Dunn
- School of Engineering, Brown University, 184 Hope Street, Providence, RI, 02912, United States
| | - Shannon E Paquette
- Department of Pathology and Laboratory Medicine, Brown University, 70 Ship Street, Providence, RI, 02903, United States
| | - Kurt D Pennell
- School of Engineering, Brown University, 184 Hope Street, Providence, RI, 02912, United States
| | - Jessica S Plavicki
- Department of Pathology and Laboratory Medicine, Brown University, 70 Ship Street, Providence, RI, 02903, United States.
| | - Katherine E Manz
- School of Engineering, Brown University, 184 Hope Street, Providence, RI, 02912, United States; Department of Environmental Health Sciences, University of Michigan, 1415 Washington Heights, Ann Arbor, MI, 48109, United States.
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3
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Wan G, Zhang Z, Chen J, Li M, Li J. GenX caused liver injury and potential hepatocellular carcinoma of mice via drinking water even at environmental concentration. Environ Pollut 2024; 346:123574. [PMID: 38365076 DOI: 10.1016/j.envpol.2024.123574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 02/06/2024] [Accepted: 02/13/2024] [Indexed: 02/18/2024]
Abstract
Hexafluoropropylene oxide dimer acid (GenX) is an alternative to perfluorooctanoic acid (PFOA), whose environmental concentration is close to its maximum allowable value established by the US Environmental Protection Agency, so its effects on human health are of great concern. The liver is one of the most crucial target organ for GenX, but whether GenX exposure induces liver cancer still unclear. In this research project, male C57 mice were disposed to GenX in drinking water at environmental concentrations (0.1 and 10 μg/L) and higher concentrations (1 and 100 mg/L) for 14 weeks to explore its effects on liver injury and potential carcinogenicity in mice. GenX was found to cause a dose-dependent increase in the serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), total cholesterol (TC), and triglyceride (TG). As the content of GenX in drinking water increased, so did the concentrations of Glypican-3 (GPC-3) and detachment gamma-carboxyprothrombin (DCP), indicators of early hepatocellular cancer. GenX destroyed the boundaries and arrangements of hepatocytes, in which monocyte infiltration, balloon-like transformation, and obvious lipid vacuoles were observed between cells. Following exposure to GenX, Masson sections revealed a significant quantity of collagen deposition in the liver. Alpha-feto protein (AFP), vascular endothelial growth factor (VEGF), Ki67, matrix metalloproteinase 2 (MMP-2) and matrix metalloproteinase 9 (MMP-9) gene expression increased in a dose-dependent manner in the treatment group relative to the control group. In general, drinking water GenX exposure induced liver function impairment, elevated blood lipid level, caused liver pathological structure damage and liver fibrosis lesions, changed the liver inflammatory microenvironment, and increased the concentration of liver-related tumor indicator even in the environmental concentration, suggesting GenX is a potential carcinogen.
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Affiliation(s)
- Guojun Wan
- Department of Occupational and Environmental Health, School of Public Health, MOE Key Laboratory of Geriatric Diseases and Immunology, Soochow University, Suzhou, 215123, China
| | - Zengli Zhang
- Department of Occupational and Environmental Health, School of Public Health, MOE Key Laboratory of Geriatric Diseases and Immunology, Soochow University, Suzhou, 215123, China
| | - Jingsi Chen
- Department of Occupational and Environmental Health, School of Public Health, MOE Key Laboratory of Geriatric Diseases and Immunology, Soochow University, Suzhou, 215123, China
| | - Mei Li
- School of Civil Engineering, Suzhou University of Science and Technology, 215011, China
| | - Jiafu Li
- Department of Occupational and Environmental Health, School of Public Health, MOE Key Laboratory of Geriatric Diseases and Immunology, Soochow University, Suzhou, 215123, China.
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Qi Y, Yang Y, Cui S, Tang X, Zhang P, Wang C, Liang Y, Sun H, Ma C, Xing B. Novel Defluorination Pathways of Perfluoroether Compounds ( GenX): α-Fe 2O 3 Nanoparticle Layer Retains Higher Concentrations of Effective Hydrated Electrons. Environ Sci Technol 2024; 58:5567-5577. [PMID: 38488517 DOI: 10.1021/acs.est.3c09879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/27/2024]
Abstract
The development of efficient defluorination technology is an important issue because the kind of emerging pollutant of hexafluoropropylene oxide dimer acid (GenX) as an alternative to perfluorooctanoic acid (PFOA) has the higher environmental risks. In the UV/bisulfite system, we first developed a hydrophobic confined α-Fe2O3 nanoparticle layer rich in oxygen vacancies, which accelerated the enrichment of HSO3- and GenX on the surface and pores through electrostatic attraction and hydrophobic interaction, retaining more hydrated electrons (eaq-) and rapidly destroying GenX under UV excitation. Especially, under anaerobic and aerobic conditions, the degradation percentage of GenX obtain nearly 100%, defluorination of GenX to 88 and 57% respectively. It was amazed to find that the three parallel H/F exchange pathways triggered by the rapid reactions of eaq- and GenX, which were unique to anaerobic conditions, improved the efficiency of fluoride removal and weaken the interference of dissolved oxygen and H+. Therefore, this study provided an available material and mechanism for sustainable fluoride removal from wastewater in aerobic and anaerobic conditions.
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Affiliation(s)
- Yuwen Qi
- 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 300071, PR China
| | - Yinbo Yang
- School of Chemical Engineering and Technology, Tianjin University, Tianjin 300354, PR China
| | - Shengyan Cui
- 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 300071, PR China
| | - Xuejiao Tang
- 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 300071, PR China
| | - Peng Zhang
- 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 300071, PR China
| | - Cuiping 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 300071, PR China
| | - Yanna Liang
- Department of Environmental and Sustainable Engineering, University at Albany, SUNY, Albany, New York 12222, United States
| | - Hongwen Sun
- 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 300071, PR China
| | - Chuanxin Ma
- Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Ecology, Environment and Resources, Guangdong University of Technology, Guangzhou 510006, PR China
| | - Baoshan Xing
- Stockbridge School of Agriculture, University of Massachusetts, Amherst, Massachusetts 01003, United States
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Boyd RI, Shokry D, Fazal Z, Rennels BC, Freemantle SJ, La Frano MR, Prins GS, Madak Erdogan Z, Irudayaraj J, Singh R, Spinella MJ. Perfluorooctanesulfonic Acid Alters Pro-Cancer Phenotypes and Metabolic and Transcriptional Signatures in Testicular Germ Cell Tumors. Toxics 2024; 12:232. [PMID: 38668455 DOI: 10.3390/toxics12040232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Revised: 03/06/2024] [Accepted: 03/12/2024] [Indexed: 04/29/2024]
Abstract
The potential effects of poly- and perfluoroalkyl substances (PFAS) are a recently emergent human and environmental health concern. There is a consistent link between PFAS exposure and cancer, but the mechanisms are poorly understood. Although epidemiological evidence supporting PFAS exposure and cancer in general is conflicting, there is relatively strong evidence linking PFAS and testicular germ cell tumors (TGCTs). However, no mechanistic studies have been performed to date concerning PFAS and TGCTs. In this report, the effects of the legacy PFAS perfluorooctanesulfonic acid (PFOS) and the newer "clean energy" PFAS lithium bis(trifluoromethylsulfonyl)imide (LiTFSi, called HQ-115), on the tumorigenicity of TGCTs in mice, TGCT cell survival, and metabolite production, as well as gene regulation were investigated. In vitro, the proliferation and survival of both chemo-sensitive and -resistant TGCT cells were minimally affected by a wide range of PFOS and HQ-115 concentrations. However, both chemicals promoted the growth of TGCT cells in mouse xenografts at doses consistent with human exposure but induced minimal acute toxicity, as assessed by total body, kidney, and testis weight. PFOS, but not HQ-115, increased liver weight. Transcriptomic alterations of PFOS-exposed normal mouse testes were dominated by cancer-related pathways and gene expression alterations associated with the H3K27me3 polycomb pathway and DNA methylation, epigenetic pathways that were previously showed to be critical for the survival of TGCT cells after cisplatin-based chemotherapy. Similar patterns of PFOS-mediated gene expression occurred in PFOS-exposed cells in vitro. Metabolomic studies revealed that PFOS also altered metabolites associated with steroid biosynthesis and fatty acid metabolism in TGCT cells, consistent with the proposed ability of PFAS to mimic fatty acid-based ligands controlling lipid metabolism and the proposed role of PFAS as endocrine disrupters. Our data, is the first cell and animal based study on PFAS in TGCTs, support a pro-tumorigenic effect of PFAS on TGCT biology and suggests epigenetic, metabolic, and endocrine disruption as potential mechanisms of action that are consistent with the non-mutagenic nature of the PFAS class.
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Affiliation(s)
- Raya I Boyd
- Department of Comparative Biosciences, University of Illinois Urbana-Champaign, 2001 South Lincoln Avenue, Urbana, IL 61801, USA
| | - Doha Shokry
- Department of Comparative Biosciences, University of Illinois Urbana-Champaign, 2001 South Lincoln Avenue, Urbana, IL 61801, USA
| | - Zeeshan Fazal
- Department of Comparative Biosciences, University of Illinois Urbana-Champaign, 2001 South Lincoln Avenue, Urbana, IL 61801, USA
| | - Brayden C Rennels
- Department of Comparative Biosciences, University of Illinois Urbana-Champaign, 2001 South Lincoln Avenue, Urbana, IL 61801, USA
| | - Sarah J Freemantle
- Department of Comparative Biosciences, University of Illinois Urbana-Champaign, 2001 South Lincoln Avenue, Urbana, IL 61801, USA
| | - Michael R La Frano
- Roy J. Carver Biotechnology Center, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
| | - Gail S Prins
- Departments of Urology, Pathology and Physiology, College of Medicine and Chicago Center for Health and Environment, University of Illinois Chicago, Chicago, IL 60612, USA
| | - Zeynep Madak Erdogan
- Department of Food Science and Human Nutrition, Division of Nutritional Sciences, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
- Carl R. Woese Institute for Genomic Biology, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
- Cancer Center of Illinois, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
| | - Joseph Irudayaraj
- Carl R. Woese Institute for Genomic Biology, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
- Cancer Center of Illinois, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
- Department of Bioengineering, University of Illinois, Urbana-Champaign, Urbana, IL 61801, USA
| | - Ratnakar Singh
- Department of Comparative Biosciences, University of Illinois Urbana-Champaign, 2001 South Lincoln Avenue, Urbana, IL 61801, USA
| | - Michael J Spinella
- Department of Comparative Biosciences, University of Illinois Urbana-Champaign, 2001 South Lincoln Avenue, Urbana, IL 61801, USA
- Carl R. Woese Institute for Genomic Biology, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
- Cancer Center of Illinois, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
- Department of Bioengineering, University of Illinois, Urbana-Champaign, Urbana, IL 61801, USA
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6
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Humphrey CP, Iverson G, Hvastkovs E, Pradhan S. Occurrence and concentrations of traditional and emerging contaminants in onsite wastewater systems and water supply wells in eastern North Carolina, USA. J Water Health 2024; 22:550-564. [PMID: 38557570 DOI: 10.2166/wh.2024.299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Accepted: 02/21/2024] [Indexed: 04/04/2024]
Abstract
Onsite wastewater treatment systems (OWTSs) and private wells are commonly used in Eastern North Carolina, USA. Water from private wells is not required to be tested after the initial startup, and thus persons using these wells may experience negative health outcomes if their water is contaminated with waste-related pollutants including bacteria, nitrate or synthetic chemicals such as hexafluoropropylne oxide dimer acid and its ammonium salt (GenX). Water samples from 18 sites with OWTSs and groundwater wells were collected for nitrate, Escherichia coli (E. coli), total coliform, and GenX concentration analyses. Results showed that none of the 18 water supplies were positive for E. coli, nitrate concentrations were all below the maximum contaminant level of 10 mg L-1, and one well had 1 MPN 100 mL-1 of total coliform. However, GenX was detected in wastewater collected from all 18 septic tanks and 22% of the water supplies tested had concentrations that exceeded the health advisory levels for GenX. Water supplies with low concentrations of traditionally tested for pollutants (nitrate, E. coli) may still pose health risks due to elevated concentrations of emerging contaminants like GenX and thus more comprehensive and routine water testing is suggested for this and similar persistent compounds.
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Affiliation(s)
- Charles P Humphrey
- Department of Health Education and Promotion, East Carolina University, 200 Curry Ct, Greenville, NC 27858, USA E-mail:
| | - Guy Iverson
- Department of Health Education and Promotion, East Carolina University, 200 Curry Ct, Greenville, NC 27858, USA
| | - Eli Hvastkovs
- Department of Chemistry, East Carolina University, 512 Science and Technology Bldg, Greenville, NC 27858, USA
| | - Sushama Pradhan
- NC Division of Public Health, Environmental Health Section, 5605 Six Forks Rd, 1632 Mail Service Center, Raleigh, NC 27699-1632, USA
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7
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Burton K, Ghadami S, Dellinger K, Wang B, Dong M. Screening Peptide-Binding Partners for GenX via Phage Display. Int J Mol Sci 2024; 25:2686. [PMID: 38473932 DOI: 10.3390/ijms25052686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 02/08/2024] [Accepted: 02/18/2024] [Indexed: 03/14/2024] Open
Abstract
Per- and poly-fluoroalkyl substances (PFAS), such as GenX, are a class of highly stable synthetic compounds that have recently become the focus of environmental remediation endeavors due to their toxicity. While considerable strides have been made in PFAS remediation, the diversity of these compounds, and the costs associated with approaches such as ion exchange resins and advanced oxidation technologies, remain challenging for widespread application. In addition, little is known about the potential binding and impacts of GenX on human proteins. To address these issues, we applied phage display and screened short peptides that bind specifically to GenX, with the ultimate goal of identifying human proteins that bind with GenX. In this study we identified the amino acids that contribute to the binding and measured the binding affinities of the two discovered peptides with NMR. A human protein, ankyrin-repeat-domain-containing protein 36B, with matching sequences of one of the peptides, was identified, and the binding positions were predicted by docking and molecular dynamics simulation. This study created a platform to screen peptides that bind with toxic chemical compounds, which ultimately helped us identify biologically relevant molecules that could be inhibited by the GenX, and also provided information that will contribute to future bioengineered GenX-binding device design.
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Affiliation(s)
- Kameron Burton
- Department of Chemistry, North Carolina Agricultural and Technical State University, Greensboro, NC 27411, USA
- Department of Nanoengineering, Joint School of Nanoscience and Nanoengineering, North Carolina Agricultural and Technical State University, Greensboro, NC 27411, USA
| | - Samaneh Ghadami
- Department of Nanoengineering, Joint School of Nanoscience and Nanoengineering, North Carolina Agricultural and Technical State University, Greensboro, NC 27411, USA
| | - Kristen Dellinger
- Department of Nanoengineering, Joint School of Nanoscience and Nanoengineering, North Carolina Agricultural and Technical State University, Greensboro, NC 27411, USA
| | - Bo Wang
- Department of Chemistry and Chemical Engineering, Florida Institute of Technology, Melbourne, FL 32901, USA
| | - Ming Dong
- Department of Chemistry and Biochemistry, University of North Carolina Wilmington, Wilmington, NC 28403, USA
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Hughes K, Pineda M, Omanovic S, Yargeau V. Study on the importance of the reductive degradation of GenX in its overall electrochemical degradation process on different cathode materials. Sci Total Environ 2024; 908:168415. [PMID: 37944604 DOI: 10.1016/j.scitotenv.2023.168415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 11/03/2023] [Accepted: 11/06/2023] [Indexed: 11/12/2023]
Abstract
Per- and polyfluoro alkylated substances (PFAS) are well known for their recalcitrant nature caused by the abundance of CF bonds. It has been proven that electrochemical degradation is a potentially suitable technique for treating PFAS; however, most studies solely focus on electrochemical oxidation, with limited attention given to electrochemical reduction, and the relative contribution of the two towards the total PFAS degradation has not yet been elucidated. This manuscript reports an investigation on the contribution of electroreduction to the overall electrodegradation of a target PFAS, HFPO-DA (i.e. GenX), using a boron doped diamond (BDD) anode and different cathode materials (Cu, Ti, Au). The oxidation and reduction reactions were successfully decoupled from each other and studied simultaneously using an electrochemical H-cell with an agar membrane. It was determined that reduction plays a significant role in the overall degradation of GenX for each of the cathodes studied, with its contribution ranging from 52 % for the Ti cathode, to 66 % for Cu, and to 92 % for Au.
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Affiliation(s)
- Kara Hughes
- Department of Chemical Engineering, McGill University Montreal, Quebec, Canada.
| | - Marco Pineda
- Department of Chemical Engineering, McGill University Montreal, Quebec, Canada
| | - Sasha Omanovic
- Department of Chemical Engineering, McGill University Montreal, Quebec, Canada
| | - Viviane Yargeau
- Department of Chemical Engineering, McGill University Montreal, Quebec, Canada
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Zhang QY, Xu LL, Zhong MT, Chen YK, Lai MQ, Wang Q, Xie XL. Gestational GenX and PFOA exposures induce hepatotoxicity, metabolic pathway, and microbiome shifts in weanling mice. Sci Total Environ 2024; 907:168059. [PMID: 37884144 DOI: 10.1016/j.scitotenv.2023.168059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 10/15/2023] [Accepted: 10/21/2023] [Indexed: 10/28/2023]
Abstract
Ammonium perfluoro (2-methyl-3-oxahexanoate) (GenX), a replacement for perfluorooctanoic acid (PFOA), has been detected in multiple environmental media and biological samples worldwide. Accumulated evidence implies that GenX exposure might exert adverse health effects, although the underlying mechanisms have not been fully revealed. In this study, pregnant BALB/c mice were exposed to GenX (2 mg/kg/day), PFOA (1 mg/kg/day), or Milli-Q water by gavage from the first day of gestation (GD0) until GD21. Necropsy and tissue collection were conducted in pups at 4 weeks of age. PFOA and GenX induced similar histopathological changes in both the liver and the intestinal mucosa, accompanied by higher serum levels of alanine and aspartate aminotransferase. Moreover, the capacity of hepatic glycogen storage and intestinal mucus secretion were significantly decreased, suggesting dysfunction of liver metabolism and the intestinal mucosal barrier. A total of 637 and 352 differentially expressed genes (DEGs) were identified in the liver tissues of GenX and PFOA group, respectively. Most of the enriched pathways from the DEGs by KEGG enrichment analysis were metabolism-associated. Moreover, overexpression of CYP4A14, Sult2a1, Cpt1b, Acaa1b, Igfbp1, Irs-2 and decreased expression of Gys2 were observed in livers of GenX exposed pups, supporting the hypothesis that there was metabolic disruption. Furthermore, DNA damage and cell cycle arrest proteins (Gadd45β, p21, Ppard) were significantly increased, while cell proliferation-related proteins (Cyclin E, Myc, EGFR) were decreased by gestational GenX exposure in the pups' liver. In addition, imbalance of gut microbiota and dysfunction of the intestinal mucosa barrier might contribute to hepatotoxicity at least in part. Taken together, our results suggested that gestational GenX exposure triggered metabolic disorder, which might be responsible for the hepatotoxicity in the pups in addition to dysfunction of the intestinal mucosa barrier. This study enriches the mechanisms of GenX-induced developmental hepatotoxicity by associating metabolic disorder with intestinal homeostasis.
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Affiliation(s)
- Qin-Yao Zhang
- Department of Toxicology, School of Public Health, Southern Medical University (Guangdong Provincial Key Laboratory of Tropical Disease Research), No. 1838 North Guangzhou Road, 510515 Guangzhou, China
| | - Ling-Ling Xu
- Department of Toxicology, School of Public Health, Southern Medical University (Guangdong Provincial Key Laboratory of Tropical Disease Research), No. 1838 North Guangzhou Road, 510515 Guangzhou, China
| | - Mei-Ting Zhong
- Department of Toxicology, School of Public Health, Southern Medical University (Guangdong Provincial Key Laboratory of Tropical Disease Research), No. 1838 North Guangzhou Road, 510515 Guangzhou, China
| | - Yu-Kui Chen
- Department of Toxicology, School of Public Health, Southern Medical University (Guangdong Provincial Key Laboratory of Tropical Disease Research), No. 1838 North Guangzhou Road, 510515 Guangzhou, China
| | - Ming-Quan Lai
- Department of Toxicology, School of Public Health, Southern Medical University (Guangdong Provincial Key Laboratory of Tropical Disease Research), No. 1838 North Guangzhou Road, 510515 Guangzhou, China
| | - Qi Wang
- Department of Forensic Pathology, School of Forensic Medicine, Southern Medical University, No. 1838 North Guangzhou Road, 510515 Guangzhou, China.
| | - Xiao-Li Xie
- Department of Toxicology, School of Public Health, Southern Medical University (Guangdong Provincial Key Laboratory of Tropical Disease Research), No. 1838 North Guangzhou Road, 510515 Guangzhou, China.
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10
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Zhang C, Tang T, Knappe DRU. Oxidation of Per- and Polyfluoroalkyl Ether Acids and Other Per- and Polyfluoroalkyl Substances by Sulfate and Hydroxyl Radicals: Kinetic Insights from Experiments and Models. Environ Sci Technol 2023; 57:18970-18980. [PMID: 37223990 PMCID: PMC10667564 DOI: 10.1021/acs.est.3c00947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Per- and polyfluoroalkyl substances (PFAS) are widely used anthropogenic chemicals. Because of the strength of the carbon-fluorine bond, PFAS are not destroyed in typical water treatment processes. Sulfate (SO4•-) and hydroxyl (•OH) radicals can oxidize some PFAS, but the behavior of per- and polyfluoroalkyl ether acids (PFEAs) in processes involving SO4•- and •OH is poorly understood. In this study, we determined second-order rate constants (k) describing the oxidation of 18 PFAS, including 15 novel PFEAs, by SO4•- and •OH. Among the studied PFAS, 6:2 fluorotelomer sulfonate reacted most readily with •OH [k•OH = (1.1-1.2) × 107 M-1 s-1], while polyfluoroalkyl ether acids containing an -O-CFH- moiety reacted more slowly [k•OH = (0.5-1.0) × 106 M-1 s-1]. In the presence of SO4•-, polyfluoroalkyl ether acids with an -O-CFH- moiety reacted more rapidly [kSO4•- = (0.89-4.6) × 106 M-1 s-1] than perfluoroalkyl ether carboxylic acids (PFECAs) and a chloro-perfluoro-polyether carboxylic acid (ClPFPECA) [kSO4•- = (0.85-9.5) × 104 M-1 s-1]. For homologous series of perfluoroalkyl carboxylic acids, linear and branched monoether PFECAs, and multiether PFECAs, PFAS chain length had little impact on second-order rate constants. SO4•- reacted with the carboxylic acid headgroup of perfluoroalkyl carboxylic acids and PFECAs. In contrast, for polyfluoroalkyl ether carboxylic and sulfonic acids with an -O-CFH- moiety, the site of SO4•- attack was the -O-CFH- moiety. Perfluoroalkyl ether sulfonic acids were not oxidized by SO4•- and •OH under the conditions evaluated in this study.
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Affiliation(s)
- Chuhui Zhang
- Department of Civil, Construction, and Environmental Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Tiffany Tang
- Department of Civil, Construction, and Environmental Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Detlef R U Knappe
- Department of Civil, Construction, and Environmental Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
- Center for Human Health and the Environment, North Carolina State University, Raleigh, North Carolina 27695, United States
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12
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Ivantsova E, Lopez-Scarim V, Sultan A, English C, Biju A, Souders CL, Padillo-Anthemides NE, Konig I, Martyniuk CJ. Evidence for neurotoxicity and oxidative stress in zebrafish embryos/larvae treated with HFPO-DA ammonium salt ( GenX). Environ Toxicol Pharmacol 2023; 104:104315. [PMID: 37984673 DOI: 10.1016/j.etap.2023.104315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 11/14/2023] [Indexed: 11/22/2023]
Abstract
"GenX" [ammonium perfluoro (2-methyl-3-oxahexanoate] was developed as a replacement chemical for toxic perfluorinated compounds to be used in product manufacturing. Here, we assessed developmental, mitochondrial, and behavioral toxicity endpoints in zebrafish embryos/larvae exposed to GenX. GenX exerted low toxicity to zebrafish embryos/larvae up to 20 mg/L. GenX did not affect mitochondrial oxidative phosphorylation nor ATP levels. ROS levels were reduced in larvae fish exposed to 10 and 100 µg/L, indicative of an antioxidant defense; however, ROS levels were elevated in fish exposed to 1000 µg/L. Increased expression of cox1 and sod2 in GenX exposed 7-day larvae was noted. GenX (0.1 or 1 µg/L) altered transcripts associated with neurotoxicity (elavl3, gfap, gap43, manf, and tubb). Locomotor activity of larvae was reduced by 100 µg/L GenX, but only in light periods. Perturbations of anxiety-related behaviors in larvae were not observed with GenX exposure. These data inform risk assessments for long-lived perfluorinated chemicals of concern.
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Affiliation(s)
- Emma Ivantsova
- Center for Environmental and Human Toxicology, Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL 32611, USA
| | - Victoria Lopez-Scarim
- Center for Environmental and Human Toxicology, Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL 32611, USA
| | - Amany Sultan
- Center for Environmental and Human Toxicology, Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL 32611, USA; Animal Health Research Institute, Agriculture Research Center (ARC), Egypt
| | - Cole English
- Center for Environmental and Human Toxicology, Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL 32611, USA
| | - Angel Biju
- Center for Environmental and Human Toxicology, Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL 32611, USA
| | - Christopher L Souders
- Center for Environmental and Human Toxicology, Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL 32611, USA
| | - Natalia E Padillo-Anthemides
- Whitney Laboratory for Marine Bioscience, University of Florida, St. Augustine, FL 32080, USA; UF Genetics Institute, Genetics and Genomics Graduate Program, USA; Department of Biology, University of Florida, Gainesville, FL 32611, USA
| | - Isaac Konig
- Center for Environmental and Human Toxicology, Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL 32611, USA; Department of Chemistry, Federal University of Lavras (UFLA), Minas Gerais, Brazil
| | - Christopher J Martyniuk
- Center for Environmental and Human Toxicology, Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL 32611, USA; UF Genetics Institute and the Interdisciplinary Program in Biomedical Sciences Neuroscience, University of Florida, USA.
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Mantripragada S, Deng D, Zhang L. Algae-Enhanced Electrospun Polyacrylonitrile Nanofibrous Membrane for High-Performance Short-Chain PFAS Remediation from Water. Nanomaterials (Basel) 2023; 13:2646. [PMID: 37836287 PMCID: PMC10574606 DOI: 10.3390/nano13192646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 09/15/2023] [Accepted: 09/23/2023] [Indexed: 10/15/2023]
Abstract
As a short-chain PFAS (per- and polyfluoroalkyl substance), GenX was produced in recent years to replace traditional long-chain PFASs, such as perfluorooctanoic acid (PFOA). However, GenX turns out to be more toxic than people originally thought, posing health risks as a persistent environmental pollutant. In this research, for the first time, we incorporated chlorella, a single-celled green freshwater microalga that grows worldwide, with polyacrylonitrile (PAN) in equal amounts in electrospun nanofibers and studied the capability of the electrospun PAN/Algae bicomponent nanofibrous membrane (ES(PAN/Algae)) to bind and remove GenX from water. The incorporation of algae demonstrated a synergistic effect and significantly improved the GenX removal efficiency of the nanofibrous membrane. The maximum GenX removal capacity reached 0.9 mmol/g at pH 6, which is significantly higher than that of most of the reported GenX adsorbents as well as activated carbon. The GenX removal mechanism was investigated and discussed by using water contact angle, zeta potential, FTIR, and XPS techniques. This research demonstrated the potential to make highly efficient adsorbent/filter materials from common and economic materials to practically remediate short-chain PFASs from various water bodies.
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Affiliation(s)
- Shobha Mantripragada
- Department of Nanoengineering, Joint School of Nanoscience and Nanoengineering, North Carolina A&T State University, Greensboro, NC 27401, USA
| | - Dongyang Deng
- Department of Built Environment, College of Science and Technology, North Carolina A&T State University, Greensboro, NC 27411, USA
| | - Lifeng Zhang
- Department of Nanoengineering, Joint School of Nanoscience and Nanoengineering, North Carolina A&T State University, Greensboro, NC 27401, USA
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He Q, Yan Z, Qian S, Xiong T, Grieger KD, Wang X, Liu C, Zhi Y. Phytoextraction of per- and polyfluoroalkyl substances (PFAS) by weeds: Effect of PFAS physicochemical properties and plant physiological traits. J Hazard Mater 2023; 454:131492. [PMID: 37121031 DOI: 10.1016/j.jhazmat.2023.131492] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 03/31/2023] [Accepted: 04/23/2023] [Indexed: 05/19/2023]
Abstract
Phytoextraction is a promising technology that uses plants to remediate contaminated soil. However, its feasibility for per- and polyfluoroalkyl substances (PFAS) and the impact of PFAS properties and plant traits on phytoextraction efficacy remains unknown. In this study, we conducted greenhouse experiment and evaluated the potential of weeds for phytoextraction of PFAS from soil and assessed the effects of PFAS properties and plant traits on PFAS uptake via systematic correlation analyses and electron probe microanalyzer with energy dispersive spectroscopy (FE-EPMA-EDS) imaging. The results showed that 1) phytoextraction can remove 0.04%- 41.4%wt of PFAS from soil, with extracted PFAS primarily stored in plant shoots; 2) Weeds preferentially extracted short-chain PFAS over long-chain homologues from soil. 3) PFAS molecular size and hydrophilicity determined plant uptake behavior, while plant morphological traits, particularly root protein and lipid content, influenced PFAS accumulation and translocation. Although plants with thin roots and small leaf areas exhibited greater PFAS uptake and storage ability, the impact of PFAS physicochemical properties was more significant. 4) Finally, short-chain PFAS were transported quickly upwards in the plant, while uptake of long-chain PFOS was restricted.
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Affiliation(s)
- Qiang He
- Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing 400044, China
| | - Zheng Yan
- Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing 400044, China
| | - Shenhua Qian
- Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing 400044, China
| | - Tiantian Xiong
- Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, School of Life Science, South China Normal University, Guangzhou 510631, China
| | - Khara D Grieger
- Department of Applied Ecology, North Carolina State University, Raleigh, NC 27695, USA; North Carolina Plant Sciences Initiative, North Carolina State University, Raleigh, NC 27606, USA
| | - Xiaoming Wang
- Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing 400044, China
| | - Caihong Liu
- Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing 400044, China
| | - Yue Zhi
- Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing 400044, China.
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Rogers JM, Heintz MM, Thompson CM, Haws LC. A putative adverse outcome network for neonatal mortality and lower birth weight in rodents: Applicability to per- and polyfluoroalkyl substances and relevance to human health. Birth Defects Res 2023. [PMID: 37219003 DOI: 10.1002/bdr2.2185] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 03/17/2023] [Accepted: 04/10/2023] [Indexed: 05/24/2023]
Abstract
BACKGROUND Some per- and poly-fluoroalkyl substances (PFAS) cause neonatal mortality and lower birth weight in rodents. We constructed an Adverse Outcome Pathway (AOP) network for neonatal mortality and lower birth weight in rodents, comprising three putative AOPs. We then assessed strengths of the evidence for the AOPs and applicability to PFAS. Finally, we considered the relevance of this AOP network to human health. METHODS Literature searches targeted PFAS, peroxisome proliferator-activated receptor (PPAR) agonists, other nuclear receptors, relevant tissues, and developmental targets. We used reviews of established biology and described results of studies with prenatal PFAS exposure that assessed birth weight and neonatal survival. Molecular initiating events (MIEs) and key events (KEs) were proposed and strengths of KE relationships (KERs), applicability to PFAS, and human relevance were assessed. RESULTS Neonatal mortality has been observed in rodents following gestational exposure to most longer chain PFAS studied, often coincident with lower birth weight. In AOP 1, PPARα activation and PPARγ activation or downregulation are MIEs; placental insufficiency, fetal nutrient restriction, neonatal hepatic glycogen deficit, and hypoglycemia are KEs leading to neonatal mortality and lower birth weight. In AOP 2, constitutive androstane receptor (CAR) and pregnane X receptor (PXR) activation upregulates Phase II metabolism, lowering maternal circulating thyroid hormones. In AOP 3, disrupted pulmonary surfactant function and PPARλ downregulation cause neonatal airway collapse and mortality from respiratory failure. CONCLUSIONS It is likely that different components of this AOP network will apply to different PFAS, largely determined by which nuclear receptors they activate. The MIEs and KEs in this AOP network can occur in humans, but differences in PPAR structure and function, and the timeline of liver and lung development, suggest that humans may be less susceptible to this AOP network. This putative AOP network elucidates knowledge gaps and research needed to better understand the developmental toxicity of PFAS.
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Yoo HJ, Pyo MC, Rhee KH, Lim JM, Yang SA, Yoo MK, Lee KW. Perfluorooctanoic acid (PFOA) and hexafluoropropylene oxide-dimer acid ( GenX): Hepatic stress and bile acid metabolism with different pathways. Ecotoxicol Environ Saf 2023; 259:115001. [PMID: 37196520 DOI: 10.1016/j.ecoenv.2023.115001] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 05/07/2023] [Accepted: 05/09/2023] [Indexed: 05/19/2023]
Abstract
Per- and polyfluoroalkyl substances (PFASs) and perfluoroalkyl ether carboxylic acids (PFECAs) are organic chemicals that are widely used in the manufacture of a wide range of human-made products. Many monitoring findings revealed the presence of PFASs and PFECAs in numerous environmental sources, including water, soil, and air, which drew more attention to both chemicals. Because of their unknown toxicity, the discovery of PFASs and PFECAs in a variety of environmental sources was viewed as a cause for concern. In the present study, male mice were given orally one of the typical PFASs, perfluorooctanoic acid (PFOA), and one of the representative PFECAs, hexafluoropropylene oxide-dimer acid (HFPO-DA). The liver index showing hepatomegaly rose significantly after 90 d of exposure to PFOA and HFPO-DA, respectively. While sharing similar suppressor genes, both chemicals demonstrated unique hepatotoxic mechanisms. In different ways, these two substances altered the expression of hepatic stress-sensing genes as well as the regulation of nuclear receptors. Not only are bile acid metabolism-related genes in the liver altered, but cholesterol metabolism-related genes as well. These results indicate that PFOA and HFPO-DA both cause hepatotoxicity and bile acid metabolism impairment with distinct mechanisms.
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Affiliation(s)
- Hee Joon Yoo
- Department of Biotechnology, College of Life Science and Biotechnology, Korea University, Seoul 02841, Republic of Korea
| | - Min Cheol Pyo
- Department of Biotechnology, College of Life Science and Biotechnology, Korea University, Seoul 02841, Republic of Korea
| | - Kyu Hyun Rhee
- Department of Biotechnology, College of Life Science and Biotechnology, Korea University, Seoul 02841, Republic of Korea
| | - Jae-Min Lim
- Department of Biotechnology, College of Life Science and Biotechnology, Korea University, Seoul 02841, Republic of Korea
| | - Seon-Ah Yang
- Department of Biotechnology, College of Life Science and Biotechnology, Korea University, Seoul 02841, Republic of Korea
| | - Min Ki Yoo
- Department of Biotechnology, College of Life Science and Biotechnology, Korea University, Seoul 02841, Republic of Korea
| | - Kwang-Won Lee
- Department of Biotechnology, College of Life Science and Biotechnology, Korea University, Seoul 02841, Republic of Korea; Department of Food Bioscience and Technology, College of Life Science and Biotechnology, Korea University, Seoul 02841, Republic of Korea.
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Qian S, Lu H, Xiong T, Zhi Y, Munoz G, Zhang C, Li Z, Liu C, Li W, Wang X, He Q. Bioaccumulation of Per- and Polyfluoroalkyl Substances (PFAS) in Ferns: Effect of PFAS Molecular Structure and Plant Root Characteristics. Environ Sci Technol 2023; 57:4443-4453. [PMID: 36848373 DOI: 10.1021/acs.est.2c06883] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
The present study assessed the bioaccumulation potential of per- and polyfluoroalkyl substances (PFAS) in ferns and linked root uptake behaviors to root characteristics and PFAS molecular structure. Tissue and subcellular-level behavioral differences between alternative and legacy PFAS were compared via an electron probe microanalyzer with energy dispersive spectroscopy (EPMA-EDS) and differential centrifugation. Our results show that ferns can accumulate PFAS from water, immobilize them in roots, and store them in harvestable tissue. The PFAS loading in roots was dominated by PFOS; however, a substantial amount of associated PFOS could be rinsed off by methanol. Correlation analyses indicated that root length, surface and project area, surface area per unit length of the root system, and molecular size and hydrophobicity of PFAS were the most significant factors affecting the magnitude of root uptake and upward translocation. EPMA-EDS images together with exposure experiments suggested that long-chain hydrophobic compounds tend to be adsorbed and retained on the root epidermis, while short-chain compounds are absorbed and quickly translocated upward. Our findings demonstrated the feasibility of using ferns in phytostabilization and phytoextraction initiatives of PFAS in the future.
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Affiliation(s)
- Shenhua Qian
- Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing 400044, China
| | - Hongying Lu
- Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing 400044, China
| | - Tiantian Xiong
- Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, School of Life Science, South China Normal University, Guangzhou 510631, China
| | - Yue Zhi
- Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing 400044, China
| | - Gabriel Munoz
- Department of Chemistry, Université de Montréal, Montreal, QC H2V 0B3, Canada
| | - Chuhui Zhang
- Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, Colorado 80401, United States
| | - Zhengwei Li
- Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing 400044, China
| | - Caihong Liu
- Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing 400044, China
| | - Wei Li
- Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing 400044, China
| | - Xiaoming Wang
- Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing 400044, China
| | - Qiang He
- Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing 400044, China
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Rashid F, Dubinkina V, Ahmad S, Maslov S, Irudayaraj JMK. Gut Microbiome-Host Metabolome Homeostasis upon Exposure to PFOS and GenX in Male Mice. Toxics 2023; 11:281. [PMID: 36977046 PMCID: PMC10051855 DOI: 10.3390/toxics11030281] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 03/01/2023] [Accepted: 03/10/2023] [Indexed: 06/18/2023]
Abstract
Alterations of the normal gut microbiota can cause various human health concerns. Environmental chemicals are one of the drivers of such disturbances. The aim of our study was to examine the effects of exposure to perfluoroalkyl and polyfluoroalkyl substances (PFAS)-specifically, perfluorooctane sulfonate (PFOS) and 2,3,3,3-tetrafluoro-2-(heptafluoropropoxy) propanoic acid (GenX)-on the microbiome of the small intestine and colon, as well as on liver metabolism. Male CD-1 mice were exposed to PFOS and GenX in different concentrations and compared to controls. GenX and PFOS were found to have different effects on the bacterial community in both the small intestine and colon based on 16S rRNA profiles. High GenX doses predominantly led to increases in the abundance of Clostridium sensu stricto, Alistipes, and Ruminococcus, while PFOS generally altered Lactobacillus, Limosilactobacillus, Parabacteroides, Staphylococcus, and Ligilactobacillus. These treatments were associated with alterations in several important microbial metabolic pathways in both the small intestine and colon. Untargeted LC-MS/MS metabolomic analysis of the liver, small intestine, and colon yielded a set of compounds significantly altered by PFOS and GenX. In the liver, these metabolites were associated with the important host metabolic pathways implicated in the synthesis of lipids, steroidogenesis, and in the metabolism of amino acids, nitrogen, and bile acids. Collectively, our results suggest that PFOS and GenX exposure can cause major perturbations in the gastrointestinal tract, aggravating microbiome toxicity, hepatotoxicity, and metabolic disorders.
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Affiliation(s)
- Faizan Rashid
- Biomedical Research Center, Mills Breast Cancer Institute, Carle Foundation Hospital, Urbana, IL 61801, USA
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
| | - Veronika Dubinkina
- Department of Bioengineering, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
- Carl R. Woese Institute for Genomic Biology, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
| | - Saeed Ahmad
- Biomedical Research Center, Mills Breast Cancer Institute, Carle Foundation Hospital, Urbana, IL 61801, USA
- Department of Bioengineering, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
| | - Sergei Maslov
- Department of Bioengineering, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
- Carl R. Woese Institute for Genomic Biology, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
| | - Joseph Maria Kumar Irudayaraj
- Biomedical Research Center, Mills Breast Cancer Institute, Carle Foundation Hospital, Urbana, IL 61801, USA
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
- Department of Bioengineering, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
- Micro and Nanotechnology Laboratory, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
- Cancer Center at Illinois, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
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Wang X, Zhang W, Lamichhane S, Dou F, Ma X. Effects of physicochemical properties and co-existing zinc agrochemicals on the uptake and phytotoxicity of PFOA and GenX in lettuce. Environ Sci Pollut Res Int 2023; 30:43833-43842. [PMID: 36680712 DOI: 10.1007/s11356-023-25435-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 01/16/2023] [Indexed: 06/17/2023]
Abstract
Even though the potential toxicity and treatment methods for per- and polyfluoroalkyl substances (PFAS) have attracted extensive attention, the plant uptake and accumulation of PFAS in edible plant tissues as a potential pathway for human exposure received little attention. Our study in a hydroponic system demonstrated that perfluorooctanoic acid (PFOA) and its replacing compound, 2,3,3,3-tetrafluoro-2-(heptafluoropropoxy) propanoic acid (GenX) displayed markedly different patterns of plant uptake and accumulation. For example, the root concentration factor (RCF) of PFOA in lettuce is almost five times of that of GenX while the translocation factor (TF) of GenX is about 66.7% higher than that for PFOA. The co-presence of zinc amendments affected the phyto-effect of these two compounds and their accumulation in plant tissues, and the net effect on their plant accumulation depended on both the properties of Zn amendments and PFAS. Zinc oxide nanoparticles (ZnONPs) at 100 mg/L did not affect the uptake of PFOA in either lettuce roots or shoots; however, Zn2+ at the same concentration significantly increased PFOA accumulation in both tissues. In contrast, both Zn amendments significantly lowered the accumulation of GenX in lettuce roots, but only ZnONPs significantly hindered the GenX accumulation in lettuce shoots. The co-exposure to ZnONPs and PFOA/GenX resulted in lower oxidative stress than the plants exposed to PFOA or GenX alone. However, both zinc agrochemicals with or without PFAS led to lower root dry biomass. The results shed light on the property-dependent plant uptake of PFAS and the potential impact of co-existing nanoagrochemicals and their dissolved ions on plant uptake of PFOA and GenX.
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Affiliation(s)
- Xiaoxuan Wang
- Zachry Department of Civil and Environmental Engineering, Texas A&M University, College Station, TX, 77843, USA
| | - Weilan Zhang
- Department of Environmental and Sustainable Engineering, University at Albany, State University of New York, Albany, NY, 12222, USA
| | | | - Fugen Dou
- Texas A&M Agrilife Research Center, Beaumont, TX, 77713, USA
| | - Xingmao Ma
- Zachry Department of Civil and Environmental Engineering, Texas A&M University, College Station, TX, 77843, USA.
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Robarts DR, Paine-Cabrera D, Kotulkar M, Venneman KK, Gunewardena S, Corton JC, Lau C, Foquet L, Bial G, Apte U. Identifying Human Specific Adverse Outcome Pathways of Per- and Polyfluoroalkyl Substances Using Liver-Chimeric Humanized Mice. bioRxiv 2023:2023.02.01.526711. [PMID: 36778348 PMCID: PMC9915685 DOI: 10.1101/2023.02.01.526711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Background Per- and polyfluoroalkyl substances (PFAS) are persistent organic pollutants with myriad adverse effects. While perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) are the most common contaminants, levels of replacement PFAS, such as perfluoro-2-methyl-3-oxahexanoic acid (GenX), are increasing. In rodents, PFOA, PFOS, and GenX have several adverse effects on the liver, including nonalcoholic fatty liver disease. Objective We aimed to determine human-relevant mechanisms of PFAS induced adverse hepatic effects using FRG liver-chimeric humanized mice with livers repopulated with functional human hepatocytes. Methods Male humanized mice were treated with 0.067 mg/L of PFOA, 0.145 mg/L of PFOS, or 1 mg/L of GenX in drinking water for 28 days. Liver and serum were collected for pathology and clinical chemistry, respectively. RNA-sequencing coupled with pathway analysis was used to determine molecular mechanisms. Results PFOS caused a significant decrease in total serum cholesterol and LDL/VLDL, whereas GenX caused a significant elevation in LDL/VLDL with no change in total cholesterol and HDL. PFOA had no significant changes in serum LDL/VLDL and total cholesterol. All three PFAS induced significant hepatocyte proliferation. RNA-sequencing with alignment to the human genome showed a total of 240, 162, and 619 differentially expressed genes after PFOA, PFOS, and GenX exposure, respectively. Upstream regulator analysis revealed inhibition of NR1D1, a transcriptional repressor important in circadian rhythm, as the major common molecular change in all PFAS treatments. PFAS treated mice had significant nuclear localization of NR1D1. In silico modeling showed PFOA, PFOS, and GenX potentially interact with the DNA-binding domain of NR1D1. Discussion These data implicate PFAS in circadian rhythm disruption via inhibition of NR1D1. These studies show that FRG humanized mice are a useful tool for studying the adverse outcome pathways of environmental pollutants on human hepatocytes in situ.
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Affiliation(s)
- Dakota R. Robarts
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, KS
| | - Diego Paine-Cabrera
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, KS
| | - Manasi Kotulkar
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, KS
| | - Kaitlyn K. Venneman
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, KS
| | - Sumedha Gunewardena
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS
| | - J. Christopher Corton
- Center for Computational Toxicology and Exposure, Office of Research and Development, U.S. EPA, Research Triangle Park, NC
| | - Christopher Lau
- Center for Public Health and Environmental Assessment, Office of Research and Development, US EPA, Research Triangle Park, NC
| | | | | | - Udayan Apte
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, KS
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Asadi Zeidabadi F, Banayan Esfahani E, McBeath ST, Dubrawski KL, Mohseni M. Electrochemical degradation of PFOA and its common alternatives: Assessment of key parameters, roles of active species, and transformation pathway. Chemosphere 2023; 315:137743. [PMID: 36608884 DOI: 10.1016/j.chemosphere.2023.137743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 12/24/2022] [Accepted: 01/02/2023] [Indexed: 06/17/2023]
Abstract
This study investigates an electrochemical approach for the treatment of water polluted with per- and poly-fluoroalkyl substances (PFAS), looking at the impact of different variables, contributions from generated radicals, and degradability of different structures of PFAS. Results obtained from a central composite design (CCD) showed the importance of mass transfer, related to the stirring speed, and the amount of charge passed through the electrodes, related to the current density on decomposition rate of PFOA. The CCD informed optimized operating conditions which we then used to study the impact of solution conditions. Acidic condition, high temperature, and low initial concentration of PFOA accelerated the degradation kinetic, while DO had a negligible effect. The impact of electrolyte concentration depended on the initial concentration of PFOA. At low initial PFOA dosage (0.2 mg L-1), the rate constant increased considerably from 0.079 ± 0.001 to 0.259 ± 0.019 min-1 when sulfate increased from 0.1% to 10%, likely due to the production of SO4•-. However, at higher initial PFOA dosage (20 mg L-1), the rate constant decreased slightly from 0.019 ± 0.001 to 0.015 ± 0.000 min-1, possibly due to the occupation of active anode sites by excess amount of sulfate. SO4•- and •OH played important roles in decomposition and defluorination of PFOA, respectively. PFOA oxidation was initiated by one electron transfer to the anode or SO4•-, undergoing Kolbe decarboxylation where yielded perfluoroalkyl radical followed three reaction pathways with •OH, O2 and/or H2O. PFAS electrooxidation depended on the chemical structures where the decomposition rate constants (min-1) were in the order of 6:2 FTCA (0.031) > PFOA (0.019) > GenX (0.013) > PFBA (0.008). PFBA with a shorter chain length and GenX with -CF3 branching had slower decomposition than PFOA. While presence of C-H bonds makes 6:2 FTCA susceptible to the attack of •OH accelerating its decomposition kinetic. Conducting experiments in mixed solution of all studied PFAS and in natural water showed that the co-presence of PFAS and other water constituents (organic and inorganic matters) had adverse effects on PFAS decomposition efficiency.
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Affiliation(s)
- Fatemeh Asadi Zeidabadi
- Department of Chemical and Biological Engineering, University of British Columbia, 2360 East Mall, Vancouver, Canada
| | - Ehsan Banayan Esfahani
- Department of Chemical and Biological Engineering, University of British Columbia, 2360 East Mall, Vancouver, Canada
| | - Sean T McBeath
- Department of Civil and Environmental Engineering, University of Massachusetts Amherst, Amherst, MA 01002, United States
| | - Kristian L Dubrawski
- Department of Civil Engineering, University of Victoria, Victoria, BC, V8P 5C2, Canada
| | - Madjid Mohseni
- Department of Chemical and Biological Engineering, University of British Columbia, 2360 East Mall, Vancouver, Canada.
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22
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Thompson CM, Heintz MM, Wolf JC, Cheru R, Haws LC, Cullen JM. Assessment of Mouse Liver Histopathology Following Exposure to HFPO-DA With Emphasis on Understanding Mechanisms of Hepatocellular Death. Toxicol Pathol 2023; 51:4-14. [PMID: 36987989 PMCID: PMC10278389 DOI: 10.1177/01926233231159078] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/30/2023]
Abstract
Ammonium 2,3,3,3-tetrafluoro-2-(heptafluoropropoxy)-propanoate (HFPO-DA) is a short chain member of per- and polyfluoroalkyl substances (PFAS). To better understand the relevance of histopathological effects seen in livers of mice exposed to HFPO-DA for human health risk assessment, histopathological effects were summarized from hematoxylin and eosin (H&E)-stained sections in several repeat-dose toxicity studies in mice. Findings across studies revealed histopathological changes consistent with peroxisomal proliferation, whereas two reports of steatosis could not be confirmed in the published figures. In addition, mechanisms of hepatocellular death were assessed in H&E sections as well as with the apoptotic marker cleaved caspase-3 (CCasp3) in newly cut sections from archived liver blocks from select studies. A comparison of serially CCasp3 immunolabeled and H&E-stained sections revealed that mechanisms of hepatocellular death cannot be clearly discerned in H&E-stained liver sections alone as several examples of putatively necrotic cells were positive for CCasp3. Published whole genome transcriptomic data were also reevaluated for enrichment of various forms of hepatocellular death in response to HFPO-DA, which revealed enrichment of apoptosis and autophagy, but not ferroptosis, pyroptosis, or necroptosis. These morphological and molecular findings are consistent with transcriptomic evidence for peroxisome proliferator-activated receptor alpha (PPARα) signaling in HFPO-DA exposed mice.
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Affiliation(s)
| | | | - Jeffrey C. Wolf
- Experimental Pathology Laboratories, Sterling, Virginia, USA
| | - Roza Cheru
- Experimental Pathology Laboratories, Sterling, Virginia, USA
| | | | - John M. Cullen
- North Carolina State University College of Veterinary Medicine, Raleigh, North Carolina, USA
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23
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Rodrigo PM, Navarathna C, Pham MTH, McClain SJ, Stokes S, Zhang X, Perez F, Gunatilake SR, Karunanayake AG, Anderson R, Thirumalai RVKG, Mohan D, Pittman CU, Mlsna TE. Batch and fixed bed sorption of low to moderate concentrations of aqueous per- and poly-fluoroalkyl substances (PFAS) on Douglas fir biochar and its Fe 3O 4 hybrids. Chemosphere 2022; 308:136155. [PMID: 36099986 DOI: 10.1016/j.chemosphere.2022.136155] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 08/17/2022] [Accepted: 08/19/2022] [Indexed: 06/15/2023]
Abstract
Per- and poly-fluoroalkyl substances (PFAS) can cause deleterious effects at low concentrations (70 ng/L). Their remediation is challenging. Aqueous μg/L levels of PFOS, PFOS, PFOSA, PFBS, GenX, PFHxS, PFPeA, PFHxA, and PFHpA (abbreviations defined in Table 1) multi-component adsorption (pH dependence, kinetics, isotherms, fixed-bed adsorption, regeneration, complex matrix) was studied on commercial Douglas fir biochar (BC) and its Fe3O4-containing BC. BC is a waste product when syn-gas is produced in a large scale from wet Douglas fir wood fed to gasification at 900-1000 °C and held for 1-20 s. This generates a relatively high surface area (∼700 m2/g) and large pore volume (∼0.25 cm3/g) biochar. Treatment of BC with FeCl3/FeSO4 and NaOH to chemically precipitate Fe3O4 onto BC. BC and its magnetic Fe3O4/BC analogue rapidly adsorbed (20-45 min equilibrium time) significant amounts of PFOS (∼14.6 mg/g) and PFOA (∼652 mg/g) at natural waters' pH range (6-8). Adsorption from μg/L concentrations has produced remediated aqueous PFAS concentrations of ∼50 ng/L or below the detection limits, which is closing in on EPA advisory limits. Column capacities of PFOS were 215.3 mg/g on BC and 51.9 mg/g Fe3O4/BC vs 53.0 mg/g and 21.8 mg/g, respectively, for PFOA. Hydrophobic and electrostatic interactions are thought to drive this sorption. Successful stripping regeneration by methanol was achieved. Thus, hydrophobic Douglas fir biochar produced by fast high temperature pyrolysis and its Fe3O4/BC analogue are adsorbent candidates for PFAS remediation from the dilute PFAS concentrations often found in polluted environments. Small Fe3O4/BC particles can be magnetically removed from batch treatments avoiding filtration.
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Affiliation(s)
- Prashan M Rodrigo
- Department of Chemistry, Mississippi State University, Mississippi State, MS, 39762-9573, USA
| | - Chanaka Navarathna
- Department of Chemistry, Mississippi State University, Mississippi State, MS, 39762-9573, USA
| | - Michael T H Pham
- Department of Chemistry, Mississippi State University, Mississippi State, MS, 39762-9573, USA
| | - Sarah J McClain
- Department of Chemistry, Mississippi State University, Mississippi State, MS, 39762-9573, USA
| | - Sean Stokes
- Department of Chemistry, Mississippi State University, Mississippi State, MS, 39762-9573, USA
| | - Xuefeng Zhang
- Department of Sustainable Bioproducts, Mississippi State University, Box 9820, Mississippi State, MS, 39762, USA
| | - Felio Perez
- Material Science Lab, Integrated Microscopy Center, University of Memphis, Memphis, TN, 38152, USA
| | - Sameera R Gunatilake
- College of Chemical Sciences, Institute of Chemistry Ceylon, Rajagiriya, CO, 10100, Sri Lanka
| | | | | | - Rooban V K G Thirumalai
- Institute of Imaging and Analytic Technology (I2AT), Mississippi State University, Mississippi State, MS, 39762, USA
| | - Dinesh Mohan
- School of Environmental Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Charles U Pittman
- Department of Chemistry, Mississippi State University, Mississippi State, MS, 39762-9573, USA
| | - Todd E Mlsna
- Department of Chemistry, Mississippi State University, Mississippi State, MS, 39762-9573, USA.
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24
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Bangma J, Guillette TC, Strynar M, Lindstrom A, McCord J, Hill D, Lau C, Chernoff N, Lang JR. A rapid assessment bioaccumulation screening (RABS) study design for emerging per-and polyfluoroalkyl substances in mice exposed to industrially impacted surface water. Chemosphere 2022; 308:136159. [PMID: 36064024 DOI: 10.1016/j.chemosphere.2022.136159] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 08/04/2022] [Accepted: 08/19/2022] [Indexed: 05/25/2023]
Abstract
The shift away from PFOS and PFOA production in the past 20 years towards shorter chain and replacement PFAS has led to the environmental release of complex mixtures of emerging PFAS for which bioaccumulation potential and toxicology are largely unknown. The rate at which emerging PFAS can be prioritized for research in these complex mixtures is often limited by the lack of available chemical standards. We developed a study design that rapidly assesses which emerging PFAS in an environmentally derived mixture have the potential for mammalian bioaccumulation and thus prioritize these emerging chemicals for standard synthesis and toxicity testing. Surface water was collected at an impacted site downstream of an industrial fluorochemical manufacturing outfall and concentrated 100-fold via weak anion exchange, solid-phase extraction. The concentrated extract contained 13 previously identified emerging PFAS, including hexafluoropropylene oxide-dimer acid (HFPO-DA). BALB/c mice were orally dosed with surface water concentrate once a day for seven days. Twenty-four hours after the last dose, liver, serum, urine, and feces were collected and the emerging PFAS were semi-quantified based on peak area counts. Of the 13 emerging PFAS, Nafion byproduct-2 (Nafion BP2), Hydro-EVE, PFO4DA, and PFO5DoA had the largest increases in percent composition when comparing serum and liver to the dosing solution, suggesting that these PFAS may have the highest bioaccumulation potential. This finding supports other studies that detected bioaccumulation of the same four PFAS in human serum collected from communities with contaminated drinking water. In the future, the Rapid Assessment Bioaccumulation Screening (RABS) study design can be extended to other complex industrial chemical mixtures impacting surface water in order to better inform chemical prioritization for acquisition and in vitro/in vivo toxicity testing of the potential pollutants.
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Affiliation(s)
- Jacqueline Bangma
- Oak Ridge Institute for Science and Education, Oak Ridge, TN, 37831, USA; Center for Environmental Measurement and Modeling, Office of Research and Development, U.S. Environmental Protection Agency, 109 T.W. Alexander Drive, Research Triangle Park, NC, 27711, USA.
| | | | - Mark Strynar
- Center for Environmental Measurement and Modeling, Office of Research and Development, U.S. Environmental Protection Agency, 109 T.W. Alexander Drive, Research Triangle Park, NC, 27711, USA
| | - Andrew Lindstrom
- Center for Environmental Measurement and Modeling, Office of Research and Development, U.S. Environmental Protection Agency, 109 T.W. Alexander Drive, Research Triangle Park, NC, 27711, USA
| | - James McCord
- Center for Environmental Measurement and Modeling, Office of Research and Development, U.S. Environmental Protection Agency, 109 T.W. Alexander Drive, Research Triangle Park, NC, 27711, USA
| | - Donna Hill
- Center for Public Health and Environmental Assessment, U.S. Environmental Protection Agency, Research Triangle Park, NC, 27711, USA
| | - Christopher Lau
- Center for Public Health and Environmental Assessment, U.S. Environmental Protection Agency, Research Triangle Park, NC, 27711, USA
| | - Neil Chernoff
- Center for Public Health and Environmental Assessment, U.S. Environmental Protection Agency, Research Triangle Park, NC, 27711, USA
| | - Johnsie R Lang
- Arcadis G&M of North Carolina, Inc. 5420 Wade Park Blvd Suite 350, Raleigh, NC, 27607, USA
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Gallocchio F, Moressa A, Zonta G, Angeletti R, Lega F. Fast and Sensitive Analysis of Short- and Long-Chain Perfluoroalkyl Substances in Foods of Animal Origin. Molecules 2022; 27:molecules27227899. [PMID: 36431997 PMCID: PMC9697276 DOI: 10.3390/molecules27227899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 10/31/2022] [Accepted: 11/07/2022] [Indexed: 11/17/2022] Open
Abstract
The availability of sensitive analytical methods to detect per- and polyfluoroalkyl substances (PFASs) in food of animal origin is fundamental for monitoring programs to collect data useful for improving risk assessment strategies. The present study aimed to develop and validate a fast and sensitive method for determining short and long-chain PFASs in meat (bovine, fish, and swine muscle), bovine liver, hen eggs, and cow’s milk to be easily applicable in routine analysis of food. A QuEChERS extraction and clean-up method in combination with liquid chromatography coupled to mass spectrometry (LC-MSMS) were used. The method resulted in good linearity (Pearson’s R > 0.99), low limits of detection (7.78−16.35 ng/kg, 8.26−34.01 ng/kg, 6.70−33.65 ng/kg, and 5.92−19.07 ng/kg for milk, liver, egg, and muscle, respectively), and appropriate limits of quantification (50 ng/kg for all compounds except for GenX and C6O4, where the limits of quantification were 100 ng/kg). Trueness and precision for all the tested levels met the acceptability criteria of 80−120% and ≤20%, respectively, regardless of the analyzed matrix. As to measurement uncertainty, it was <50% for all compound/matrix combinations. These results demonstrate the selectivity and sensitivity of the method for simultaneous trace detection and quantification of 14 PFASs in foods of animal origin, verified through the analysis of 63 food samples.
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Feng Z, McLamb F, Vu JP, Gong S, Gersberg RM, Bozinovic G. Physiological and transcriptomic effects of hexafluoropropylene oxide dimer acid in Caenorhabditis elegans during development. Ecotoxicol Environ Saf 2022; 244:114047. [PMID: 36075119 DOI: 10.1016/j.ecoenv.2022.114047] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 08/26/2022] [Accepted: 08/29/2022] [Indexed: 06/15/2023]
Abstract
Per- and polyfluoroalkyl substances (PFAS) are chemicals resistant to degradation. While such a feature is desirable in consumer and industrial products, some PFAS, including perfluorooctanoic acid (PFOA), are toxic and bioaccumulate. Hexafluoropropylene oxide dimer acid (HFPO-DA), an emerging PFAS developed to replace PFOA, has not been extensively studied. To evaluate the potential toxicity of HFPO-DA with a cost- and time-efficient approach, we exposed C. elegans larvae for 48 h to 4 × 10-9-4 g/L HFPO-DA in liquid media and measured developmental, behavioral, locomotor, and transcriptional effects at various exposure levels. Worms exposed to 1.5-4 g/L HFPO-DA were developmentally delayed, and progeny production was significantly delayed (p < 0.05) in worms exposed to 2-4 g/L HFPO-DA. Statistically significant differential gene expression was identified in all fourteen HFPO-DA exposure groups ranging from 1.25 × 10-5 to 4 g/L, except for 6.25 × 10-5 g/L. Among 10298 analyzed genes, 2624 differentially expressed genes (DEGs) were identified in the developmentally delayed 4 g/L group only, and 78 genes were differentially expressed in at least one of the thirteen groups testing 1.25 × 10-5-2 g/L HFPO-DA exposures. Genes encoding for detoxification enzymes including cytochrome P450 and UDP glucuronosyltransferases were upregulated in 0.25-4 g/L acute exposure groups. DEGs were also identified in lower exposure level groups, though they did not share biological functions except for six ribosomal protein-coding genes. While our transcriptional data is inconclusive to infer mechanisms of toxicity, the significant gene expression differences at 1.25 × 10-5 g/L, the lowest concentration tested for transcriptional changes, calls for further targeted analyses of low-dose HFPO-DA exposure effects.
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Affiliation(s)
- Zuying Feng
- Boz Life Science Research and Teaching Institute, 3030 Bunker Hill Street, San Diego, CA, USA; School of Public Health, San Diego State University, 5500 Campanile Drive, San Diego, CA, USA.
| | - Flannery McLamb
- Boz Life Science Research and Teaching Institute, 3030 Bunker Hill Street, San Diego, CA, USA; Division of Extended Studies, University of California San Diego, 9600N. Torrey Pines Road, La Jolla, CA, USA.
| | - Jeanne P Vu
- Boz Life Science Research and Teaching Institute, 3030 Bunker Hill Street, San Diego, CA, USA; School of Public Health, San Diego State University, 5500 Campanile Drive, San Diego, CA, USA; Division of Extended Studies, University of California San Diego, 9600N. Torrey Pines Road, La Jolla, CA, USA.
| | - Sylvia Gong
- Boz Life Science Research and Teaching Institute, 3030 Bunker Hill Street, San Diego, CA, USA; School of Public Health, San Diego State University, 5500 Campanile Drive, San Diego, CA, USA; Division of Extended Studies, University of California San Diego, 9600N. Torrey Pines Road, La Jolla, CA, USA.
| | - Richard M Gersberg
- School of Public Health, San Diego State University, 5500 Campanile Drive, San Diego, CA, USA.
| | - Goran Bozinovic
- Boz Life Science Research and Teaching Institute, 3030 Bunker Hill Street, San Diego, CA, USA; School of Public Health, San Diego State University, 5500 Campanile Drive, San Diego, CA, USA; Division of Biological Sciences, University of California San Diego, 9500 Gilman Dr., La Jolla, CA, USA.
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Attema B, Janssen AW, Rijkers D, van Schothorst EM, Hooiveld GJ, Kersten S. Exposure to low-dose perfluorooctanoic acid promotes hepatic steatosis and disrupts the hepatic transcriptome in mice. Mol Metab 2022; 66:101602. [PMID: 36115532 PMCID: PMC9526138 DOI: 10.1016/j.molmet.2022.101602] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 09/07/2022] [Accepted: 09/13/2022] [Indexed: 12/29/2022] Open
Abstract
OBJECTIVE Perfluoroalkyl substances (PFAS) are man-made chemicals with demonstrated endocrine-disrupting properties. Exposure to perfluorooctanoic acid (PFOA) has been linked to disturbed metabolism via the liver, although the exact mechanism is not clear. Moreover, information on the metabolic effects of the new PFAS alternative GenX is limited. We examined whether exposure to low-dose PFOA and GenX induces metabolic disturbances in mice, including NAFLD, dyslipidemia, and glucose tolerance, and studied the involvement of PPARα. METHODS Male C57BL/6J wildtype and PPARα-/- mice were given 0.05 or 0.3 mg/kg body weight/day PFOA, or 0.3 mg/kg body weight/day GenX while being fed a high-fat diet for 20 weeks. Glucose and insulin tolerance tests were performed after 18 and 19 weeks. Plasma metabolite levels were measured next to a detailed assessment of the liver phenotype, including lipid content and RNA sequencing. RESULTS Exposure to high-dose PFOA decreased body weight and increased liver weight in wildtype and PPARα-/- mice. High-dose but not low-dose PFOA reduced plasma triglycerides and cholesterol, which for triglycerides was dependent on PPARα. PFOA and GenX increased hepatic triglycerides in a PPARα-dependent manner. RNA sequencing showed that the effects of GenX on hepatic gene expression were entirely dependent on PPARα, while the effects of PFOA were mostly dependent on PPARα. In the absence of PPARα, the involvement of PXR and CAR became more prominent. CONCLUSION Overall, we show that long-term and low-dose exposure to PFOA and GenX disrupts hepatic lipid metabolism in mice. Whereas the effects of PFOA are mediated by multiple nuclear receptors, the effects of GenX are entirely mediated by PPARα. Our data underscore the potential of PFAS to disrupt metabolism by altering signaling pathways in the liver.
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Affiliation(s)
- Brecht Attema
- Nutrition, Metabolism and Genomics Group, Division of Human Nutrition and Health, Wageningen University, the Netherlands
| | | | - Deborah Rijkers
- Wageningen Food Safety Research (WFSR), Wageningen, the Netherlands
| | | | - Guido J.E.J. Hooiveld
- Nutrition, Metabolism and Genomics Group, Division of Human Nutrition and Health, Wageningen University, the Netherlands
| | - Sander Kersten
- Nutrition, Metabolism and Genomics Group, Division of Human Nutrition and Health, Wageningen University, the Netherlands,Corresponding author. Division of Human Nutrition and Health, Wageningen University, Stippeneng 4, 6708 WE Wageningen, Netherlands.
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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: 37] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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Zhu Y, Ji H, He K, Blaney L, Xu T, Zhao D. Photocatalytic degradation of GenX in water using a new adsorptive photocatalyst. Water Res 2022; 220:118650. [PMID: 35640506 DOI: 10.1016/j.watres.2022.118650] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 05/19/2022] [Accepted: 05/21/2022] [Indexed: 06/15/2023]
Abstract
GenX, the ammonium salt of hexafluoropropylene oxide dimer acid, has been used as a replacement for perfluorooctanoic acid. Due to its widespread uses, GenX has been detected in waters around the world amid growing concerns about its persistence and adverse health effects. As relevant regulations are rapidly evolving, new technologies are needed to cost-effectively remove and degrade GenX. In this study, we developed an adsorptive photocatalyst by depositing a small amount (3 wt.%) of bismuth (Bi) onto activated-carbon supported titanate nanotubes, Bi/TNTs@AC, and tested the material for adsorption and subsequent solid-phase photodegradation of GenX. Bi/TNTs@AC at 1 g/L was able to adsorb GenX (100 µg/L, pH 7.0) within 1 h, and then degrade 70.0% and mineralize 42.7% of pre-sorbed GenX under UV (254 nm) in 4 h. The efficient degradation also regenerated the material, allowing for repeated uses without chemical regeneration. Material characterizations revealed that the active components of Bi/TNTs@AC included activated carbon, anatase, and Bi nanoparticles with a metallic Bi core and an amorphous Bi2O3 shell. Electron paramagnetic resonance spin-trapping, UV-vis diffuse reflectance spectrometry, and photoluminescence analyses indicated the superior photoactivity of Bi/TNTs@AC was attributed to enhanced light harvesting and generation of charge carriers due to the UV-induced surface plasmon resonance effect, which was enabled by the metallic Bi nanoparticles. •OH radicals and photogenerated holes (h+) were responsible for degradation of GenX. Based on the analysis of degradation byproducts and density functional theory calculations, photocatalytic degradation of GenX started with cleavage of the carboxyl group and/or ether group by •OH, h+, and/or eaq-, and the resulting intermediates were transformed into shorter-chain fluorochemicals following the stepwise defluorination mechanism. Bi/TNTs@AC holds the potential for more cost-effective degradation of GenX and other per- and polyfluorinated alkyl substances.
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Affiliation(s)
- Yangmo Zhu
- Department of Civil & Environmental Engineering, Auburn University, Auburn, AL 36849, USA
| | - Haodong Ji
- School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055, China
| | - Ke He
- Department of Chemical, Biochemical, and Environmental Engineering, University of Maryland Baltimore County, MD 21250, USA
| | - Lee Blaney
- Department of Chemical, Biochemical, and Environmental Engineering, University of Maryland Baltimore County, MD 21250, USA
| | - Tianyuan Xu
- School of Resource and Geosciences, China University of Mining and Technology, Xuzhou, Jiangsu 221116, China.
| | - Dongye Zhao
- Department of Civil & Environmental Engineering, Auburn University, Auburn, AL 36849, USA.
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Robarts DR, Venneman KK, Gunewardena S, Apte U. GenX induces fibroinflammatory gene expression in primary human hepatocytes. Toxicology 2022; 477:153259. [PMID: 35850385 PMCID: PMC9741548 DOI: 10.1016/j.tox.2022.153259] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 07/12/2022] [Accepted: 07/14/2022] [Indexed: 01/09/2023]
Abstract
The toxicity induced by the persistent organic pollutants per- and polyfluoroalkyl substances (PFAS) is dependent on the length of their polyfluorinated tail. Long-chain PFASs have significantly longer half-lives and profound toxic effects compared to their short-chain counterparts. Recently, production of a short-chain PFAS substitute called ammonium 2,3,3,3-tetrafluoro-2-(heptafluoropropoxy) propanoate, also known as GenX, has significantly increased. However, the adverse health effects of GenX are not completely known. In this study, we investigated the dose-dependent effects of GenX on primary human hepatocytes (PHH). Freshly isolated PHH were treated with either 0.1, 10, or 100 μM of GenX for 48 and 96 h; then, global transcriptomic changes were determined using Human Clariom™ D arrays. GenX-induced transcriptional changes were similar at 0.1 and 10 μM doses but were significantly different at the 100 μM dose. Genes involved in lipid, monocarboxylic acid, and ketone metabolism were significantly altered following exposure of PHH at all doses. However, at the 100 μM dose, GenX caused changes in genes involved in cell proliferation, inflammation and fibrosis. A correlation analysis of concentration and differential gene expression revealed that 576 genes positively (R > 0.99) and 375 genes negatively (R < -0.99) correlated with GenX concentration. The upstream regulator analysis indicated HIF1α was inhibited at the lower doses but were activated at the higher dose. Additionally, VEGF, PPARα, STAT3, and SMAD4 signaling was induced at the 100 µM dose. These data indicate that at lower doses GenX can interfere with metabolic pathways and at higher doses can induce fibroinflammatory changes in human hepatocytes.
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Affiliation(s)
- Dakota R Robarts
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS, USA.
| | - Kaitlyn K Venneman
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS, USA.
| | - Sumedha Gunewardena
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS, USA.
| | - Udayan Apte
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS, USA.
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Zhang C, McElroy AC, Liberatore HK, Alexander NLM, Knappe DR. Stability of Per- and Polyfluoroalkyl Substances in Solvents Relevant to Environmental and Toxicological Analysis. Environ Sci Technol 2022; 56:6103-6112. [PMID: 34734715 PMCID: PMC9065217 DOI: 10.1021/acs.est.1c03979] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Per- and polyfluoroalkyl substances (PFASs) are widely used anthropogenic chemicals. For environmental and toxicological analysis, it is important to understand the stability of PFASs, including novel per- and polyfluoroalkyl ether acids (PFEAs), in commonly used solvents. In this study, we investigated the effects of PFAS characteristics, solvent type, water-to-organic solvent ratio, and temperature on the stability of 21 PFASs including 18 PFEAs. None of the studied PFASs showed measurable degradation in deionized water, methanol, or isopropyl alcohol over 30 days; however, nine PFEAs degraded in the polar aprotic solvents acetonitrile, acetone, and dimethyl sulfoxide (DMSO). PFEA degradation followed first-order kinetics, and first-order rate constants increased with increasing temperature and with decreasing water-to-organic solvent ratio. Monoethers with a carboxylic acid functional group adjacent to a tertiary carbon (>CF-COOH) degraded more rapidly than multiethers in which the carboxylic acid moiety was adjacent to repeating -CF2O- groups. In contrast, monoethers with a carboxylic acid moiety adjacent to a secondary carbon (-CF2-COOH) were stable in all tested solvents. Using high-resolution mass spectrometry, we determined that PFEAs with a >CF-COOH group were stoichiometrically decarboxylated in aprotic solvents and formed products with a >CFH group; e.g., hexafluoropropylene oxide-dimer acid (HFPO-DA or GenX), HFPO-trimer acid, and HFPO-tetramer acid were stoichiometrically converted to Fluoroethers E-1, E-2, and E-3, respectively. PFEA degradation results highlight the importance of solvent choice when preparing dosing solutions and performing extractions for environmental and toxicological assessments of PFEAs.
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Affiliation(s)
- Chuhui Zhang
- Department of Civil, Construction, and Environmental Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Amie C. McElroy
- Department of Civil, Construction, and Environmental Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Hannah K. Liberatore
- Center for Environmental Measurement and Modeling, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, United States
| | - Nancy Lee M. Alexander
- Department of Civil, Construction, and Environmental Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Detlef R.U. Knappe
- Department of Civil, Construction, and Environmental Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
- Center for Human Health and the Environment, North Carolina State University, Raleigh, North Carolina 27695, United States
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Xu LL, Chen YK, Zhang QY, Chen LJ, Zhang KK, Li JH, Liu JL, Wang Q, Xie XL. Gestational exposure to GenX induces hepatic alterations by the gut-liver axis in maternal mice: A similar mechanism as PFOA. Sci Total Environ 2022; 820:153281. [PMID: 35066053 DOI: 10.1016/j.scitotenv.2022.153281] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 01/09/2022] [Accepted: 01/16/2022] [Indexed: 05/27/2023]
Abstract
GenX is an alternative to perfluorooctanoic acid (PFOA) and was included in the accession list of Substances of Very High Concern in 2019. Gestational GenX exposure induces maternal hepatotoxicity in animals. However, the mechanisms of GenX toxicity have not been explored. In the present study, pregnant Balb/c mice were administered with PFOA (1 mg/kg BW/day), GenX (2 mg/kg BW/day), or Milli-Q water by gavage during gestation. Similar hepatic pathological changes, including enlargement of hepatocytes, cytoplasm loss, nucleus migration, inflammatory cell infiltration, and reduction of glycogen storage, were observed in PFOA and GenX groups. Increased expression levels of indicators of the TLR4 pathway indicated activation of inflammation in the liver of maternal mice after exposure to PFOA or GenX, consistent with the pathological changes. Overexpression of cleaved PARP-1, cleaved caspase 3, Bax and decreased Bcl-2 proteins indicated activation of apoptosis, whereas overexpression of ULK-1, p62, beclin-1, LC3-II proteins and downregulation of p-mTOR implied that PFOA and GenX exposure initiated autophagy. Decreased secretion of mucus, reduced expression levels of tight junction proteins, and higher serum levels of lipopolysaccharide indicated disruption of the intestinal barrier. Translocation of lipopolysaccharide may be recognized by TLR4, thus triggering inflammatory pathway in the maternal liver. In summary, gestational exposure to PFOA or GenX induced maternal hepatic alterations through the gut-liver axis.
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Affiliation(s)
- Ling-Ling Xu
- Department of Toxicology, School of Public Health, Southern Medical University (Guangdong Provincial Key Laboratory of Tropical Disease Research), No. 1838 North Guangzhou Road, 510515 Guangzhou, China
| | - Yu-Kui Chen
- Department of Toxicology, School of Public Health, Southern Medical University (Guangdong Provincial Key Laboratory of Tropical Disease Research), No. 1838 North Guangzhou Road, 510515 Guangzhou, China
| | - Qin-Yao Zhang
- Department of Toxicology, School of Public Health, Southern Medical University (Guangdong Provincial Key Laboratory of Tropical Disease Research), No. 1838 North Guangzhou Road, 510515 Guangzhou, China
| | - Li-Jian Chen
- Department of Forensic Pathology, School of Forensic Medicine, Southern Medical University, No. 1838 North Guangzhou Road, 510515 Guangzhou, China
| | - Kai-Kai Zhang
- Department of Forensic Pathology, School of Forensic Medicine, Southern Medical University, No. 1838 North Guangzhou Road, 510515 Guangzhou, China
| | - Jia-Hao Li
- Department of Forensic Pathology, School of Forensic Medicine, Southern Medical University, No. 1838 North Guangzhou Road, 510515 Guangzhou, China
| | - Jia-Li Liu
- Department of Forensic Pathology, School of Forensic Medicine, Southern Medical University, No. 1838 North Guangzhou Road, 510515 Guangzhou, China
| | - Qi Wang
- Department of Forensic Pathology, School of Forensic Medicine, Southern Medical University, No. 1838 North Guangzhou Road, 510515 Guangzhou, China.
| | - Xiao-Li Xie
- Department of Toxicology, School of Public Health, Southern Medical University (Guangdong Provincial Key Laboratory of Tropical Disease Research), No. 1838 North Guangzhou Road, 510515 Guangzhou, China.
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Suresh Babu D, Mol JMC, Buijnsters JG. Experimental insights into anodic oxidation of hexafluoropropylene oxide dimer acid ( GenX) on boron-doped diamond anodes. Chemosphere 2022; 288:132417. [PMID: 34606896 DOI: 10.1016/j.chemosphere.2021.132417] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Revised: 09/24/2021] [Accepted: 09/28/2021] [Indexed: 06/13/2023]
Abstract
GenX is the trade name of the ammonium salt of hexafluoropropylene oxide dimer acid (HFPO-DA) and is used as a replacement for the banned perfluorooctanoic acid (PFOA). However, recent studies have found GenX to be more toxic than PFOA. This work deals with the electrochemical degradation of HFPO-DA using boron-doped diamond anodes. For the first time, an experimental study was conducted to investigate the influence of sulfate concentration and other operating parameters on HFPO-DA degradation. Results demonstrated that sulfate radicals were ineffective in HFPO-DA degradation due to steric hindrance by -CF3 branch. Direct electron transfer was found as the rate-determining step. By comparing degradation of HFPO-DA with that of PFOA, it was observed that the steric hindrance by -CF3 branch in HFPO-DA decreased the rate of electron transfer from the carboxyl head group even though its defluorination rate was faster. Conclusively, a degradation pathway is proposed in which HFPO-DA mineralizes to CO2 and F- via formation of three intermediates.
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Affiliation(s)
- Diwakar Suresh Babu
- Department of Materials Science and Engineering, Delft University of Technology, Mekelweg 2, 2628 CD Delft, The Netherlands.
| | - Johannes M C Mol
- Department of Materials Science and Engineering, Delft University of Technology, Mekelweg 2, 2628 CD Delft, The Netherlands.
| | - Josephus G Buijnsters
- Department of Precision and Microsystems Engineering, Research Group of Micro and Nano Engineering, Delft University of Technology, Mekelweg 2, 2628 CD Delft, The Netherlands.
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Adi MA, Altarawneh M. Thermal decomposition of heptafluoropropylene-oxide-dimer acid ( GenX). Chemosphere 2022; 289:133118. [PMID: 34863723 DOI: 10.1016/j.chemosphere.2021.133118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 11/25/2021] [Accepted: 11/27/2021] [Indexed: 06/13/2023]
Abstract
Incineration appears as a viable strategy in the disposal of the notorious perfluoroalkyl substances (PFASs) in a process that typically leads to fluorine mineralization. Central in the design of such operation is to comprehend the underlying chemical mechanisms that dictate thermal fragmentation of PFASs into smaller perfluorinated cuts and HF. Among notable short-chain PFASs entities is the heptafluoropropylene-oxide-dimer acid (HFPO-DA, C5F11C(O)OH), commercially known as GenX synthesized as a possible replacement of other PFASs compounds. However, reaction pathways that underpin the degradation of GenX at temperatures relevant to its decomposition in incinerators (i.e., cement kilns), remain unknown. Herein, we map out all plausible initial reactions that govern the thermal decomposition of GenX. Simultaneous elimination of HF and CO2 appears as the kinetically most favored channel with an accessible activation enthalpy of ∼62.0 kcal/mol. Fission of the ether linkage in the 1,1,1,2,2,3,3-heptafluoro-3-[(1-fluoroethenyl)oxy] propane molecule (that forms after HF/CO2 elimination) affords a wide array of CnFm cuts, most notably CF2 at elevated temperatures. Constructed kinetic model plots temperature-dependent profiles of important species. It is predicted that GenX to commence decomposition around 700 K at a residence time of 2.0 s, a value that is generally applied in incinerators. Findings from the study call to further investigate interactions between the predicted major fluorine carriers (HF and CF2) and other constituents encountered in relevant incineration mediums, most notably, calcium hydroxides and polymeric materials.
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Affiliation(s)
- Maissa A Adi
- Department of Chemical and Petroleum Engineering, United Arab Emirates University, PO Box 15551, Al-Ain, United Arab Emirates
| | - Mohammednoor Altarawneh
- Department of Chemical and Petroleum Engineering, United Arab Emirates University, PO Box 15551, Al-Ain, United Arab Emirates.
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Liu YL, Sun M. Ion exchange removal and resin regeneration to treat per- and polyfluoroalkyl ether acids and other emerging PFAS in drinking water. Water Res 2021; 207:117781. [PMID: 34731662 DOI: 10.1016/j.watres.2021.117781] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 10/12/2021] [Accepted: 10/13/2021] [Indexed: 05/27/2023]
Abstract
Ion exchange (IX) is a promising technology to remove legacy anionic per- and polyfluoroalkyl substances (PFAS) from water. As increasing numbers of per- and polyfluoroalkyl ether acids (PFEA) and other emerging PFAS were detected in the environment, it is necessary to understand how well IX resins remove these emerging PFAS for drinking water treatment. In this study, nine commercially available IX resins were tested to treat a drinking water source spiked with 40 legacy and emerging PFAS at 600 ng/L, including PFEA, perfluoroalkyl carboxylic and sulfonic acids, fluorotelomer sulfonic acids, perfluoroalkane sulfonamides, perfluoroalkane sulfonamidoacetic acids, and zwitterionic species. With limited contact time (15 min), PFAS properties such as the fluorinated chain length, charge, and functional groups all affected PFAS adsorption to resins. However, the impact of PFAS properties on PFAS removal became less pronounced when the contact time increased beyond 2 h, while the resin polymer matrix became the critical factor for PFAS removal. All five tested polystyrene-divinylbenzene (PS-DVB) resins achieved more than 90% removal in 24 h of 35 PFAS compounds, while polymethacrylate and polyacrylic resins achieved >90% removal for less than half of the compounds. Regenerating PS-DVB resin was investigated using different salt species, regenerant pH, brine concentrations, and methanol contents. Sodium chloride and ammonium chloride were found the best brines for regenerating the tested resins. Increasing brine concentrations enhanced the regeneration efficiency, especially for short-chain PFAS. Using simple salt regenerants, up to 94% of selected short-chain PFAS was released from resins designed for general water treatment, but no meaningful regeneration was achieved for long-chain PFAS or PFAS-specific resins when the organic solvent content was less than 20%.
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Affiliation(s)
- Yen-Ling Liu
- Department of Civil and Environmental Engineering, University of North Carolina at Charlotte, Charlotte, NC, 28223, United States
| | - Mei Sun
- Department of Civil and Environmental Engineering, University of North Carolina at Charlotte, Charlotte, NC, 28223, United States.
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Chambers WS, Hopkins JG, Richards SM. A Review of Per- and Polyfluorinated Alkyl Substance Impairment of Reproduction. Front Toxicol 2021; 3:732436. [PMID: 35295153 PMCID: PMC8915888 DOI: 10.3389/ftox.2021.732436] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 10/29/2021] [Indexed: 01/09/2023] Open
Abstract
In this review article, we compiled peer-reviewed literature describing PFAS exposure and reproductive effects in animals and humans. The aim was to compare environmental occurrence and effects of the most prominent long-chain PFAS compounds and their short-chain replacements. Long-chain PFAS compounds are known to persist in the environment due to their chemical stability, and also known to bioaccumulate; hence, these compounds are being replaced globally. Indeed, PFOA and PFOS are considered long-chain "forever pollutants," and thus the potential reproductive risk may continue for decades. Much less is known about their short-chain replacements despite the fact that they becoming more widespread in the environment. Short-chain PFAS are generally less bioaccumulative than long-chain, but they are more mobile and persistent in aquatic ecosystems. The three most prominent of these are commonly referred to as GenX, ADONA and F53B. The short-chain PFAS have similar physical and chemical properties as their predecessors; however, because they are relatively new, much less is known about the potential to disrupt reproduction. Indeed, high-quality epidemiological studies are needed to determine associations between short-chain PFAS exposure and effects on reproductive health. However, epidemiological evidence is mounting that long-chain PFAS exposure is associated with reproductive effects (i.e., decrease in fertility, reduced fetal growth and birth weight, pregnancy-induced hypertension and preeclampsia, thyroid hormone disruption during pregnancy, and preterm birth). Evidence from animal models and human cell lines indicates that short-chain PFAS similarly affect reproductive endpoints; however, epidemiological studies are scarce and inconsistent. Although short-chain PFAS have been quantified in drinking water and sediment worldwide, most of these studies did not focus on quantitation of GenX, ADONA, and F53B. There are also many other short-chain PFAS byproducts of manufacturing that have yet to be identified and studied. When sum total concentration of long- and short-chain PFAS are considered, the concentration rises by an order or magnitude or greater, as will the risk of exposure and subsequent reproductive effects.
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Affiliation(s)
- Weston S. Chambers
- Department of Biology, Geology and Environmental Sciences, University of Tennessee at Chattanooga, Chattanooga, TN, United States
| | - Jaida G. Hopkins
- Department of Biology, Geology and Environmental Sciences, University of Tennessee at Chattanooga, Chattanooga, TN, United States
| | - Sean M. Richards
- Department of Biology, Geology and Environmental Sciences, University of Tennessee at Chattanooga, Chattanooga, TN, United States
- Department of Obstetrics and Gynecology, Section on Maternal-Fetal Medicine, University of Tennessee College of Medicine, Chattanooga, TN, United States
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Cope HA, Blake BE, Love C, McCord J, Elmore SA, Harvey JB, Chappell VA, Fenton SE. Latent, sex-specific metabolic health effects in CD-1 mouse offspring exposed to PFOA or HFPO-DA ( GenX) during gestation. Emerg Contam 2021; 7:219-235. [PMID: 35097227 PMCID: PMC8794304 DOI: 10.1016/j.emcon.2021.10.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
BACKGROUND Perfluorooctanoic acid (PFOA) is an environmental contaminant associated with adverse metabolic outcomes in developmentally exposed human populations and mouse models. Hexafluoropropylene oxide-dimer acid (HFPO-DA, commonly called GenX) has replaced PFOA in many industrial applications in the U.S. and Europe and has been measured in global water systems from <1 to 9350 ng/L HFPO-DA. Health effects data for GenX are lacking. OBJECTIVE Determine the effects of gestational exposure to GenX on offspring weight gain trajectory, adult metabolic health, liver pathology and key adipose gene pathways in male and female CD-1 mice. METHODS Daily oral doses of GenX (0.2, 1.0, 2.0 mg/kg), PFOA (0.1, 1.0 mg/kg), or vehicle control were administered to pregnant mice (gestation days 1.5-17.5). Offspring were fed a high- or low-fat diet (HFD or LFD) at weaning until necropsy at 6 or 18 weeks, and metabolic endpoints were measured over time. PFOA and GenX serum and urine concentrations, weight gain, serum lipid parameters, body mass composition, glucose tolerance, white adipose tissue gene expression, and liver histopathology were evaluated. RESULTS Prenatal exposure to GenX led to its accumulation in the serum and urine of 5-day old pups (P = 0.007, P < 0.001), which was undetectable by weaning. By 18 weeks of age, male mice fed LFD in the 2.0 mg/kg GenX group displayed increased weight gain (P < 0.05), fat mass (P = 0.016), hepatocellular microvesicular fatty change (P = 0.015), and insulin sensitivity (P = 0.014) in comparison to control males fed LFD. Female mice fed HFD had a significant increase in hepatocyte single cell necrosis in 1.0 mg/kg GenX group (P = 0.022) and 1.0 mg/kg PFOA group (P = 0.003) compared to control HFD females. Both sexes were affected by gestational GenX exposure; however, the observed phenotype varied between sex with males displaying more characteristics of metabolic disease and females exhibiting liver damage in response to the gestational exposure. CONCLUSIONS Prenatal exposure to 1 mg/kg GenX and 1 mg/kg PFOA induces adverse metabolic outcomes in adult mice that are diet- and sex-dependent. GenX also accumulated in pup serum, suggesting that placental and potentially lactational transfer are important exposure routes for GenX.
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Affiliation(s)
- Harlie A. Cope
- National Toxicology Program Laboratory, Division of the National Toxicology Program (DNTP), National Institutes of Environmental Health Sciences (NIEHS), National Institutes of Health (NIH), Research Triangle Park, NC, USA
| | - Bevin E. Blake
- National Toxicology Program Laboratory, Division of the National Toxicology Program (DNTP), National Institutes of Environmental Health Sciences (NIEHS), National Institutes of Health (NIH), Research Triangle Park, NC, USA
| | - Charlotte Love
- National Toxicology Program Laboratory, Division of the National Toxicology Program (DNTP), National Institutes of Environmental Health Sciences (NIEHS), National Institutes of Health (NIH), Research Triangle Park, NC, USA
| | - James McCord
- Multimedia Methods Branch, Center for Environmental Measurement and Modeling, Office of Research and Development, U.S. Environmental Protection Agency, RTP, NC, USA
| | - Susan A. Elmore
- Cellular and Molecular Pathology Branch, DNTP, NIEHS, NIH, RTP, NC, USA
| | - Janice B. Harvey
- Cellular and Molecular Pathology Branch, DNTP, NIEHS, NIH, RTP, NC, USA
| | - Vesna A. Chappell
- National Toxicology Program Laboratory, Division of the National Toxicology Program (DNTP), National Institutes of Environmental Health Sciences (NIEHS), National Institutes of Health (NIH), Research Triangle Park, NC, USA
| | - Suzanne E. Fenton
- National Toxicology Program Laboratory, Division of the National Toxicology Program (DNTP), National Institutes of Environmental Health Sciences (NIEHS), National Institutes of Health (NIH), Research Triangle Park, NC, USA
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Langenbach B, Wilson M. Per- and Polyfluoroalkyl Substances (PFAS): Significance and Considerations within the Regulatory Framework of the USA. Int J Environ Res Public Health 2021; 18:ijerph182111142. [PMID: 34769660 PMCID: PMC8583519 DOI: 10.3390/ijerph182111142] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 10/13/2021] [Accepted: 10/20/2021] [Indexed: 01/09/2023]
Abstract
Per- and polyfluoroalkyl substances (PFAS) are an emerging environmental crisis. Deemed forever chemicals, many congeners bioaccumulate and are incredibly persistent in the environment due to the presence of the strong carbon-fluorine covalent bonds. Notable PFAS compounds include perfluorooctanesulfonic acid (PFOS), perfluorooctanoic acid (PFOA), and GenX. Robust toxicological knowledge exists for these substances, but regulatory decisions based on this knowledge has fallen behind. The United States Environmental Protection Agency (EPA) has addressed this issue with the PFAS Action Plan and EPA Council on PFAS, but the regulatory framework is severely lacking. Currently, no federal regulations or standards exist. Many occupational and non-occupational human cohorts exist that can lend knowledge on the environmental implications of PFAS and associated health effects. Occupationally, firefighters face significant exposure risks due to use of PFAS containing aqueous film-forming foams (AFFFs) and personal protective equipment contamination. Non-occupationally, wastewater discharge in North Carolina led to chronic and widespread residential exposure to GenX via drinking water contamination. This public health review seeks to convey the current and future significance of PFAS as an environmental contaminate, to lend considerations on regulatory frameworks within the USA, and to help guide and promote the need for future epidemiological studies in order to tackle this environmental emergency. While the PFAS Action Plan creates a scientific and regulatory foundation, it is important to take these lessons and apply them to future environmental health issues.
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Davidsen N, Rosenmai AK, Lauschke K, Svingen T, Vinggaard AM. Developmental effects of PFOS, PFOA and GenX in a 3D human induced pluripotent stem cell differentiation model. Chemosphere 2021; 279:130624. [PMID: 34134420 DOI: 10.1016/j.chemosphere.2021.130624] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 04/14/2021] [Accepted: 04/17/2021] [Indexed: 06/12/2023]
Abstract
Polyfluoroalkyl substances (PFASs), including perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), are persistent pollutants routinely found in human blood. PFASs have been associated with health issues such as decreased birth weight and impaired vaccination response in children. Substitutes to these PFASs, such as ammonium 2,3,3,3-tetrafluoro-2-(heptafluoropropoxy)propanoate (GenX) have been introduced, although hazard information is limited. Human induced pluripotent stem cell (hiPSC) based models are valuable for studying these compounds, as they mimic human embryonic development. We used our recently developed PluriBeat assay to investigate PFOS, PFOA and GenX for effects on early embryonic development in vitro. In our assay hiPSCs go through the early stages of embryonic development in 3D cultures of embryoid bodies (EBs) that mimic the human blastocyst until they finally form beating cardiomyocytes. Both PFOS and PFOA had a strong effect on cardiomyocyte differentiation at non-cytotoxic concentrations, with PFOS being more potent than PFOA. Moreover, both compounds decreased EB size at the highest test concentrations. GenX induced a weak concentration-dependent effect on differentiation of one hiPSC line, but not of another. Transcriptional analysis of mRNA from the cardiomyocytes showed that PFOS increased expression of the early cardiac marker ISL1, whereas PFOA decreased expression of the cardiomyocyte marker MYH7. This suggest that PFOS and PFOA perturb cardiomyocyte differentiation by disrupting molecular pathways similar to those taking place in the developing embryo. Based on these findings, we conclude that our PluriBeat assay has the potential to become a valuable, sensitive model system for elucidating embryotoxic effects of PFASs in future.
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Affiliation(s)
- Nichlas Davidsen
- National Food Institute, Technical University of Denmark, Kgs. Lyngby DK, 2800, Denmark
| | | | - Karin Lauschke
- National Food Institute, Technical University of Denmark, Kgs. Lyngby DK, 2800, Denmark
| | - Terje Svingen
- National Food Institute, Technical University of Denmark, Kgs. Lyngby DK, 2800, Denmark
| | - Anne Marie Vinggaard
- National Food Institute, Technical University of Denmark, Kgs. Lyngby DK, 2800, Denmark.
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Xu B, Liu S, Zhou JL, Zheng C, Weifeng J, Chen B, Zhang T, Qiu W. PFAS and their substitutes in groundwater: Occurrence, transformation and remediation. J Hazard Mater 2021; 412:125159. [PMID: 33951855 DOI: 10.1016/j.jhazmat.2021.125159] [Citation(s) in RCA: 86] [Impact Index Per Article: 28.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 12/29/2020] [Accepted: 01/13/2021] [Indexed: 05/27/2023]
Abstract
Poly- and perfluoroalkyl substances (PFAS) are increasingly investigated due to their global occurrence and potential human health risk. The ban on PFOA and PFOS has led to the use of novel substitutes such as GenX, F-53B and OBS. This paper reviews the studies on the occurrence, transformation and remediation of major PFAS i.e. PFOA, PFNA, PFBA, PFOS, PFHxS, PFBS and the three substitutes in groundwater. The data indicated that PFOA, PFBA, PFOS and PFBS were present at high concentrations up to 21,200 ng L-1 while GenX and F-53B were found up to 30,000 ng L-1 and 0.18-0.59 ng L-1, respectively. PFAS in groundwater are from direct sources e.g. surface water and soil. PFAS remediation methods based on membrane, redox, sorption, electrochemical and photocatalysis are analyzed. Overall, photocatalysis is considered to be an ideal technology with low cost and high degradation efficacy for PFAS removal. Photocatalysis could be combined with electrochemical or membrane filtration to become more advantageous. GenX, F-53B and OBS in groundwater treatment by UV/sulfite system and electrochemical oxidation proved effective. The review identified gaps such as the immobilization and recycling of materials in groundwater treatment, and recommended visible light photocatalysis for future studies.
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Affiliation(s)
- Bentuo Xu
- National and Local Joint Engineering Research Center of Ecological Treatment Technology for Urban Water Pollution, School of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China
| | - Shuai Liu
- Research Institute of Poyang Lake, Jiangxi Academy of Sciences, Nanchang 330012, China
| | - John L Zhou
- Centre for Green Technology, School of Civil and Environmental Engineering, University of Technology Sydney, 15 Broadway, NSW 2007, Australia
| | - Chunmiao Zheng
- Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control, State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Jin Weifeng
- National and Local Joint Engineering Research Center of Ecological Treatment Technology for Urban Water Pollution, School of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China
| | - Bei Chen
- Fisheries Research Institute of Fujian, Xiamen 361013, China
| | - Ting Zhang
- Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control, State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Wenhui Qiu
- Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control, State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China.
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Roostaei J, Colley S, Mulhern R, May AA, Gibson JM. Predicting the risk of GenX contamination in private well water using a machine-learned Bayesian network model. J Hazard Mater 2021; 411:125075. [PMID: 33858085 DOI: 10.1016/j.jhazmat.2021.125075] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 01/04/2021] [Accepted: 01/05/2021] [Indexed: 06/12/2023]
Abstract
Per- and polyfluoroalkyl substances (PFAS) are emerging contaminants that pose significant challenges in mechanistic fate and transport modeling due to their diverse and complex chemical characteristics. Machine learning provides a novel approach for predicting the spatial distribution of PFAS in the environment. We used spatial location information to link PFAS measurements from 1207 private drinking water wells around a fluorochemical manufacturing facility to a mechanistic model of PFAS air deposition and to publicly available data on soil, land use, topography, weather, and proximity to multiple PFAS sources. We used the resulting linked data set to train a Bayesian network model to predict the risk that GenX, a member of the PFAS class, would exceed a state provisional health goal (140 ng/L) in private well water. The model had high accuracy (ROC curve index for five-fold cross-validation of 0.85, 90% CI 0.84-0.87). Among factors significantly associated with GenX risk in private wells, the most important was the historic rate of atmospheric deposition of GenX from the fluorochemical manufacturing facility. The model output was used to generate spatial risk predictions for the study area to aid in risk assessment, environmental investigations, and targeted public health interventions.
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Affiliation(s)
- Javad Roostaei
- Department of Environmental and Occupational Health, Indiana University, Bloomington, IN 47405, United States
| | - Sarah Colley
- Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, Chapel Hill 27516, United States
| | - Riley Mulhern
- Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, Chapel Hill 27516, United States
| | - Andrew A May
- Department of Civil, Environmental and Geodetic Engineering, Ohio State University, Columbus, OH 43210, United States
| | - Jacqueline MacDonald Gibson
- Department of Environmental and Occupational Health, Indiana University, Bloomington, IN 47405, United States.
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Pike KA, Edmiston PL, Morrison JJ, Faust JA. Correlation Analysis of Perfluoroalkyl Substances in Regional U.S. Precipitation Events. Water Res 2021; 190:116685. [PMID: 33279752 DOI: 10.1016/j.watres.2020.116685] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 11/21/2020] [Accepted: 11/25/2020] [Indexed: 05/28/2023]
Abstract
Per- and polyfluoroalkyl substances (PFAS) are transported in the atmosphere, leading to both wet and dry deposition to the surface. The concentrations of 15 PFAS were measured at six locations in the Ohio-Indiana region of the U.S. during the summer of 2019 and compared to samples collected at a distant site in NW Wyoming. ΣPFAS concentrations ranged from 50-850 ng L-1, with trifluoroacetic acid (TFA) being the dominant compound (~90%). Concentrations of perfluorooctanoic acid (PFOA) and perfluorosulfonic acid (PFOS) were similar to amounts observed over the past 20 years, indicating persistence in the atmosphere despite regulatory action, and the newer species HFPO-DA (GenX) was also widely detected in rainwater. ANOVA modeling and correlation matrices were used to determine association of PFAS concentrations, location, and functional group and chain length. Statistically significant differences (p < 0.05) in PFAS profiles across sites separated by 10-100 km indicate that local point sources strongly contribute to wet deposition. This work introduces correlation plots for PFAS that allow rapid visual comparison of multi-analyte and multi-site data sets.
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Affiliation(s)
- Kyndal A Pike
- Department of Chemistry, College of Wooster, 943 College Mall, Wooster, Ohio 44691, United States; Department of Mathematical and Computational Sciences, College of Wooster, 308 E. University, Wooster, Ohio 44691, United States
| | - Paul L Edmiston
- Department of Chemistry, College of Wooster, 943 College Mall, Wooster, Ohio 44691, United States
| | - Jillian J Morrison
- Department of Mathematical and Computational Sciences, College of Wooster, 308 E. University, Wooster, Ohio 44691, United States
| | - Jennifer A Faust
- Department of Chemistry, College of Wooster, 943 College Mall, Wooster, Ohio 44691, United States.
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Dixit F, Barbeau B, Mostafavi SG, Mohseni M. PFAS and DOM removal using an organic scavenger and PFAS-specific resin: Trade-off between regeneration and faster kinetics. Sci Total Environ 2021; 754:142107. [PMID: 32920395 DOI: 10.1016/j.scitotenv.2020.142107] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 08/10/2020] [Accepted: 08/29/2020] [Indexed: 05/27/2023]
Abstract
Treatment technologies such as ion exchange (IX) process exhibit promising potentials for the removal of toxic per- and poly-fluoroalkyl substances (PFAS) from natural waters. In recent years, industries have started manufacturing PFAS-specific resins which are typically operated in a single use-and-dispose mode until exhaustion. However, this increases the resin demand and the consequent operational cost and environmental burden of the IX process. In this study, the performance of a PFAS-specific resin (A592) was compared with that of a regenerative organic scavenger resin (A860) which is traditionally employed for dissolved organic matter (DOM) and micorpollutant removal. Comparative studies were performed to examine the removal of multiple long- and short-chain carboxylic, sulfonic, precursor and emerging PFAS (including GenX) from synthetic and natural waters. The A592 resin exhibited faster uptake kinetics for PFAS while simultaneously removing 10-15% of DOM. The A860 resin removed ~60-70% of DOM; however, it required approximately 3-fold higher contact times for achieving the same degree of PFAS removal when compared to the PFAS-specific resin. The resin breakthrough (Ctreated (PFAS) > 70 ng/L) was observed around 125,000 ± 5000 bed volumes (BVs) for the PFAS-specific resin (via multiple loading tests), while it ranged between 15,000-27,000 BVs for the organic scavenger. Yet, a mass balance on PFAS and DOM removal indicated ~90-98% site saturation (in milli-equivalents (meqs)) on both IX resins before exhaustion. More importantly, the regenerated organic scavenger resin (A860) exhibited PFAS and DOM removal capabilities for longer operational BVs when compared to A592 operated in a single-use-mode in natural waters.
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Affiliation(s)
- Fuhar Dixit
- Department of Chemical and Biological Engineering, University of British Columbia, Vancouver, Canada
| | - Benoit Barbeau
- Department of Civil, Geological and Mining Engineering, Polytechnique Montreal, Quebec, Canada
| | - Shadan Ghavam Mostafavi
- Department of Chemical and Biological Engineering, University of British Columbia, Vancouver, Canada
| | - Madjid Mohseni
- Department of Chemical and Biological Engineering, University of British Columbia, Vancouver, Canada.
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Reisz B, Belova V, Duva G, Zeiser C, Hodas M, Hagara J, Šiffalovič P, Pithan L, Hosokai T, Hinderhofer A, Gerlach A, Schreiber F. Polymorphism and structure formation in copper phthalocyanine thin films. J Appl Crystallogr 2021; 54:203-210. [PMID: 33833648 PMCID: PMC7941321 DOI: 10.1107/s1600576720015472] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 11/22/2020] [Indexed: 11/30/2022] Open
Abstract
This X-ray diffraction study proves that two α polymorphs of copper pthalocyanine (CuPc) co-exist in vacuum-deposited thin films and provides possible molecular configurations by excluded-volume considerations. Furthermore, atomic force microscopy images together with a simple MATLAB simulation show that elevated substrate temperatures facilitate the downward diffusion of CuPc molecules during film growth and lead to a smoother surface. Many polymorphic crystal structures of copper phthalocyanine (CuPc) have been reported over the past few decades, but despite its manifold applicability, the structure of the frequently mentioned α polymorph remained unclear. The base-centered unit cell (space group C2/c) suggested in 1966 was ruled out in 2003 and was replaced by a primitive triclinic unit cell (space group P1). This study proves unequivocally that both α structures coexist in vacuum-deposited CuPc thin films on native silicon oxide by reciprocal space mapping using synchrotron radiation in grazing incidence. The unit-cell parameters and the space group were determined by kinematic scattering theory and provide possible molecular arrangements within the unit cell of the C2/c structure by excluded-volume considerations. In situ X-ray diffraction experiments and ex situ atomic force microscopy complement the experimental data further and provide insight into the formation of a smooth thin film by a temperature-driven downward diffusion of CuPc molecules during growth.
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Affiliation(s)
- Berthold Reisz
- Institute for Applied Physics, University of Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany
| | - Valentina Belova
- Institute for Applied Physics, University of Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany
| | - Giuliano Duva
- Institute for Applied Physics, University of Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany
| | - Clemens Zeiser
- Institute for Applied Physics, University of Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany
| | - Martin Hodas
- Institute for Applied Physics, University of Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany
| | - Jakub Hagara
- Institute of Physics, Slovak Academy of Sciences, Dúbravská cesta 9, 845 11 Bratislava 45, Slovak Republic
| | - Peter Šiffalovič
- Institute of Physics, Slovak Academy of Sciences, Dúbravská cesta 9, 845 11 Bratislava 45, Slovak Republic
| | - Linus Pithan
- European Synchrotron Radiation Facility, 71 avenue des Martyrs CS 402200, 38043 Grenoble Cedex 9, France
| | - Takuya Hosokai
- National Metrology Institute of Japan (NMIJ), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 5, 1-1-1 Azuma, Tsukuba, Ibaraki 305-8565, Japan
| | - Alexander Hinderhofer
- Institute for Applied Physics, University of Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany
| | - Alexander Gerlach
- Institute for Applied Physics, University of Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany
| | - Frank Schreiber
- Institute for Applied Physics, University of Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany
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Brase RA, Mullin EJ, Spink DC. Legacy and Emerging Per- and Polyfluoroalkyl Substances: Analytical Techniques, Environmental Fate, and Health Effects. Int J Mol Sci 2021; 22:995. [PMID: 33498193 DOI: 10.3390/ijms22030995] [Citation(s) in RCA: 88] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 01/12/2021] [Accepted: 01/13/2021] [Indexed: 01/24/2023] Open
Abstract
Due to their unique chemical properties, per- and polyfluoroalkyl substances (PFAS) have been used extensively as industrial surfactants and processing aids. While several types of PFAS have been voluntarily phased out by their manufacturers, these chemicals continue to be of ecological and public health concern due to their persistence in the environment and their presence in living organisms. Moreover, while the compounds referred to as “legacy” PFAS remain in the environment, alternative compounds have emerged as replacements for their legacy predecessors and are now detected in numerous matrices. In this review, we discuss the historical uses of PFAS, recent advances in analytical techniques for analysis of these compounds, and the fate of PFAS in the environment. In addition, we evaluate current biomonitoring studies of human exposure to legacy and emerging PFAS and examine the associations of PFAS exposure with human health impacts, including cancer- and non-cancer-related outcomes. Special focus is given to short-chain perfluoroalkyl acids (PFAAs) and ether-substituted, polyfluoroalkyl alternatives including hexafluoropropylene oxide dimer acid (HFPO-DA; tradename GenX), 4,8-dioxa-3H-perfluorononanoic acid (DONA), and 6:2 chlorinated polyfluoroethersulfonic acid (6:2 Cl-PFESA; tradename F-53B).
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Bangma J, Szilagyi J, Blake BE, Plazas C, Kepper S, Fenton SE, Fry RC. An assessment of serum-dependent impacts on intracellular accumulation and genomic response of per- and polyfluoroalkyl substances in a placental trophoblast model. Environ Toxicol 2020; 35:1395-1405. [PMID: 32790152 PMCID: PMC7738272 DOI: 10.1002/tox.23004] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 07/07/2020] [Accepted: 07/11/2020] [Indexed: 05/18/2023]
Abstract
Per- and polyfluoroalkyl substances (PFAS), a class of environmental contaminants, have been detected in human placenta and cord blood. The mechanisms driving PFAS-induced effects on the placenta and adverse pregnancy outcomes are not well understood. This study investigated the impact of perfluorooctanesulfonic acid (PFOS), perfluorooctanoic acid (PFOA), and a replacement PFAS known as hexafluoropropylene oxide dimer acid (HFPO-DA, tradename GenX) on placental trophoblasts in vitro. Several key factors were addressed. First, PFAS levels in cell culture reagents at baseline were quantified. Second, the role of supplemental media serum in intracellular accumulation of PFAS in a human trophoblast (JEG3) cell line was established. Finally, the impact of PFAS on the expression of 96 genes involved in proper placental function in JEG3 cells was evaluated. The results revealed that serum-free media (SFM) contained no detectable PFAS. In contrast, fetal bovine serum-supplemented media (SSM) contained PFNA, PFUdA, PFTrDA, and 6:2 FTS, but these PFAS were not detected internally in cells. Intracellular accumulation following 24 hr treatments was significantly higher when cultured in SFM compared to SSM for PFOS and PFOA, but not HFPO-DA. Treatment with PFAS was associated with gene expression changes (n = 32) in pathways vital to placental function, including viability, syncytialization, inflammation, transport, and invasion/mesenchymal transition. Among the most robust PFAS-associated changes were those observed in the known apoptosis-related genes, BAD and BAX. These results suggest a complex relationship between PFAS, in vitro culture conditions, and altered expression of key genes necessary for proper placentation.
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Affiliation(s)
- Jacqueline Bangma
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - John Szilagyi
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Curriculum in Toxicology & Environmental Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Bevin E. Blake
- Curriculum in Toxicology & Environmental Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, NC
- Division of the National Toxicology Program (DNTP), NTP Laboratory, National Institute of Environmental Health Sciences (NIEHS), Research Triangle Park, North Carolina, USA
| | - Cinthya Plazas
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Stewart Kepper
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Suzanne E. Fenton
- Division of the National Toxicology Program (DNTP), NTP Laboratory, National Institute of Environmental Health Sciences (NIEHS), Research Triangle Park, North Carolina, USA
| | - Rebecca C Fry
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Institute for Environmental Health Solutions, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC
- Curriculum in Toxicology & Environmental Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, NC
- Corresponding author: Rebecca Fry, PhD, , Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC
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Semerád J, Hatasová N, Grasserová A, Černá T, Filipová A, Hanč A, Innemanová P, Pivokonský M, Cajthaml T. Screening for 32 per- and polyfluoroalkyl substances (PFAS) including GenX in sludges from 43 WWTPs located in the Czech Republic - Evaluation of potential accumulation in vegetables after application of biosolids. Chemosphere 2020; 261:128018. [PMID: 33113642 DOI: 10.1016/j.chemosphere.2020.128018] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 07/22/2020] [Accepted: 08/13/2020] [Indexed: 06/11/2023]
Abstract
Highly persistent, toxic and bioaccumulative per - and polyfluoroalkyl substances (PFAS) represents a serious problem for the environment and their concentrations and fate remain largely unknown. The present study consists of a PFAS screening in sludges originating from 43 wastewater treatment plants (WWTPs) in the Czech Republic. To analyze an extended group of PFAS consisting of 32 PFAS, including GenX and other new replacements of older and restricted PFAS in sludge, a new method was optimized and validated using pressurized solvent extraction, followed by the SPE clean-up step to eliminate the observed matrix effects and LC-MS/MS. The results revealed high PFAS contamination of sewage sludge, reaching values from 5.6 to 963.2 ng g-1. The results showed that in the majority of the samples (about 60%), PFOS was the most abundant among the targeted PFAS, reaching 932.9 ng g-1. Approximately 20% of the analyzed samples contained more short-chain PFAS, suggesting the replacement of long-chain PFAS (especially restricted PFOA and PFOS). GenX was detected in 9 samples, confirming the trend in the use of new PFAS. The results revealed that significantly higher contamination was detected in the samples from large WWTPs (population equivalent > 50,000; p-value <0.05). Concerning the application of sludge in agriculture, our prediction using the respective PFAS bioconcentration factors, the observed concentrations, and the legislatively permitted management of biosolids in Czech Republic agriculture revealed that PFAS can cause serious contamination of cereals and vegetables (oat, celery shoots and lettuce leaves), as well as general secondary contamination of the environment.
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Affiliation(s)
- Jaroslav Semerád
- Institute of Microbiology of the Czech Academy of Sciences, Vídeňská 1083, CZ-142 20, Prague 4, Czech Republic; Institute for Environmental Studies, Faculty of Science, Charles University, Benátská 2, CZ-128 01, Prague 2, Czech Republic
| | - Nicolette Hatasová
- Institute for Environmental Studies, Faculty of Science, Charles University, Benátská 2, CZ-128 01, Prague 2, Czech Republic
| | - Alena Grasserová
- Institute of Microbiology of the Czech Academy of Sciences, Vídeňská 1083, CZ-142 20, Prague 4, Czech Republic; Institute for Environmental Studies, Faculty of Science, Charles University, Benátská 2, CZ-128 01, Prague 2, Czech Republic
| | - Tereza Černá
- Institute of Microbiology of the Czech Academy of Sciences, Vídeňská 1083, CZ-142 20, Prague 4, Czech Republic; Institute for Environmental Studies, Faculty of Science, Charles University, Benátská 2, CZ-128 01, Prague 2, Czech Republic
| | - Alena Filipová
- Institute of Microbiology of the Czech Academy of Sciences, Vídeňská 1083, CZ-142 20, Prague 4, Czech Republic
| | - Aleš Hanč
- Department of Agro-Environmental Chemistry and Plant Nutrition, Czech University of Life Sciences Prague, Kamýcká 129, CZ-165 00, Prague 6, Czech Republic
| | - Petra Innemanová
- Institute for Environmental Studies, Faculty of Science, Charles University, Benátská 2, CZ-128 01, Prague 2, Czech Republic; Dekonta a.s., Dřetovice 109, CZ-273 42 Stehelčeves, Czech Republic
| | - Martin Pivokonský
- Institute of Hydrodynamics of the Czech Academy of Sciences, Pod Paťankou 30/5, CZ-166 12, Prague 6, Czech Republic
| | - Tomáš Cajthaml
- Institute of Microbiology of the Czech Academy of Sciences, Vídeňská 1083, CZ-142 20, Prague 4, Czech Republic; Institute for Environmental Studies, Faculty of Science, Charles University, Benátská 2, CZ-128 01, Prague 2, Czech Republic.
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48
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Brase RA, Spink DC. Enhanced Sensitivity for the Analysis of Perfluoroethercarboxylic Acids Using LC-ESI-MS/MS: Effects of Probe Position, Mobile Phase Additive, and Capillary Voltage. J Am Soc Mass Spectrom 2020; 31:2124-2132. [PMID: 32794713 DOI: 10.1021/jasms.0c00244] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Perfluoroethercarboxylic acids (PFECAs) have recently emerged as replacements for toxic per- and polyfluorinated alkyl substances (PFAS) including perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS). Compared with other PFAS, many PFECAs including hexafluoropropylene oxide dimer acid (HFPO-DA, trade name GenX) exhibit poor sensitivity during analysis using liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) and are therefore often difficult to quantify. This study examined changes in ESI probe position, mobile phase additive, and capillary voltage with the goal of enhancing PFECA sensitivity. In addition, the relative contributions of existing mechanistic theories for PFAS ionization during ESI are discussed. Results indicated that the LC-ESI-MS/MS sensitivity for 9 PFECAs can be improved significantly by altering the ESI probe position. At the optimal probe position, lowering the capillary voltage from 2.0 to 0.5 kV universally enhanced the LC-ESI-MS/MS sensitivity for PFAS analysis. For most analytes, the use of ammonium bicarbonate rather than ammonium acetate as a mobile phase additive also enhanced the analytical response. These effects have not been previously reported and suggest that many laboratories may be conducting analyses of PFECAs under suboptimal conditions. Using the strategies outlined in this study, PFECAs can be more easily incorporated into comprehensive methods for PFAS analysis. Here, we describe analytical parameters that enhance the sensitivity for some PFECAs by up to 36-fold while maintaining high sensitivity for legacy PFAS. This work not only highlights solutions to mitigate inadequate PFECA sensitivity but also provides insight into the mechanisms underlying PFAS ionization efficiency during LC-ESI-MS/MS.
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Affiliation(s)
- Richard A Brase
- Laboratory of Organic Analytical Chemistry, Wadsworth Center, New York State Department of Health, and Department of Environmental Health Sciences, School of Public Health, University at Albany, State University of New York, Albany, New York 12237, United States
| | - David C Spink
- Laboratory of Organic Analytical Chemistry, Wadsworth Center, New York State Department of Health, and Department of Environmental Health Sciences, School of Public Health, University at Albany, State University of New York, Albany, New York 12237, United States
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49
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Dixit F, Barbeau B, Mostafavi SG, Mohseni M. Removal of legacy PFAS and other fluorotelomers: Optimized regeneration strategies in DOM-rich waters. Water Res 2020; 183:116098. [PMID: 32663697 DOI: 10.1016/j.watres.2020.116098] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 06/15/2020] [Accepted: 06/21/2020] [Indexed: 06/11/2023]
Abstract
We present the first study investigating optimized regeneration strategies for anionic ion exchange (IX) resins during the removal of persistent per- and poly-fluoroalkyl substances (PFAS, including GenX) from surface and treated wastewater effluents. IX regeneration studies are of critical importance from environmental perspectives. Specifically, the knowledge is essential for water utilities who presently operate IX (for PFAS removal) in a single use-and-dispose mode. In this study, legacy PFAS such as PFOA/PFOS were tested along with other harmful short-chained PFAS (PFBA/PFBS) and other toxic perfluorinated substitutes (GenX). Studies were performed on synthetic water (spiked with Suwannee River Natural Organic Matter (SRNOM), Fulvic Acid (SRFA) and Humic Acid (SRHA)), surface water, and wastewater effluents, and the regeneration was performed in batch stirred reactors. The resin service life with and without regeneration was investigated in the presence of background organic matter. In ultra-pure waters, all PFAS (C0 ∼10 μg/L, concentrations similar to that of natural waters) were effectively removed for >100,000 Bed Volume (BV) of operation. This was reduced to ∼23,500 BV in the presence of SRNOM (C0 = 5 mg C/L), 20,500 BV in SRFA and 8500 BV in SRHA, after which the saturated resins required regeneration. More importantly, all resin breakthrough (PFAS> 70 ng/L) corresponded to > 90% resin site saturation (in meqs), an essential information for optimizing IX loading. The competitive dissolved organic matter (DOM) fractions were estimated to be approximately 5-9% of the initial DOC, as estimated by the IAST-EBC model. Finally, it was identified that IX regeneration efficiency improved with increasing brine contact time but effectiveness plateaued for brine concentrations above 10% (W/V). Nonetheless, a regeneration with 10% NaCl solution with a contact time of 2 h was found to be optimal for IX operations in synthetic and natural waters. Therefore, this study provides key knowledge essential for the scientific community and the water industry on optimizing IX operational parameters for DOM and PFAS removal and would be highly valuable for systems which presently operate IX in a use-and-dispose mode.
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Affiliation(s)
- Fuhar Dixit
- Department of Chemical and Biological Engineering, University of British Columbia, Vancouver, Canada
| | - Benoit Barbeau
- Department of Civil, Geological and Mining Engineering, Polytechnique Montreal, Quebec, Canada
| | - Shadan Ghavam Mostafavi
- Department of Chemical and Biological Engineering, University of British Columbia, Vancouver, Canada
| | - Madjid Mohseni
- Department of Chemical and Biological Engineering, University of British Columbia, Vancouver, Canada.
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50
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Chappell GA, Thompson CM, Wolf JC, Cullen JM, Klaunig JE, Haws LC. Assessment of the Mode of Action Underlying the Effects of GenX in Mouse Liver and Implications for Assessing Human Health Risks. Toxicol Pathol 2020; 48:494-508. [PMID: 32138627 PMCID: PMC7153225 DOI: 10.1177/0192623320905803] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
GenX is an alternative to environmentally persistent long-chain perfluoroalkyl and polyfluoroalkyl substances. Mice exposed to GenX exhibit liver hypertrophy, elevated peroxisomal enzyme activity, and other apical endpoints consistent with peroxisome proliferators. To investigate the potential role of peroxisome proliferator-activated receptor alpha (PPARα) activation in mice, and other molecular signals potentially related to observed liver changes, RNA sequencing was conducted on paraffin-embedded liver sections from a 90-day subchronic toxicity study of GenX conducted in mice. Differentially expressed genes were identified for each treatment group, and gene set enrichment analysis was conducted using gene sets that represent biological processes and known canonical pathways. Peroxisome signaling and fatty acid metabolism were among the most significantly enriched gene sets in both sexes at 0.5 and 5 mg/kg GenX; no pathways were enriched at 0.1 mg/kg. Gene sets specific to the PPARα subtype were significantly enriched. These findings were phenotypically anchored to histopathological changes in the same tissue blocks: hypertrophy, mitoses, and apoptosis. In vitro PPARα transactivation assays indicated that GenX activates mouse PPARα. These results indicate that the liver changes observed in GenX-treated mice occur via a mode of action (MOA) involving PPARα, an important finding for human health risk assessment as this MOA has limited relevance to humans.
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Affiliation(s)
| | | | | | - John M. Cullen
- North Carolina State University College of Veterinary Medicine, Raleigh, NC, USA
| | - James E. Klaunig
- Indiana University, School of Public Health, Bloomington, IN, USA
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