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González-Alvarez ME, Antwi-Boasiako C, Keating AF. Effects of Per- and Polyfluoroalkylated Substances on Female Reproduction. TOXICS 2024; 12:455. [PMID: 39058107 PMCID: PMC11280844 DOI: 10.3390/toxics12070455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2024] [Revised: 06/02/2024] [Accepted: 06/18/2024] [Indexed: 07/28/2024]
Abstract
Per- and poly-fluoroalkylated substances (PFAS) are a large group of chemicals that persist both in the environment and in the body. Legacy PFAS, e.g., perfluorooctanoic acid and perfluorooctane sulfonic acid, are implicated as endocrine disruptors and reproductive and developmental toxicants in epidemiological and animal model studies. This review describes female reproductive outcomes of reported studies and includes where associative relationships between PFAS exposures and female reproductive outcomes have been observed as well as where those are absent. In animal models, studies in which PFAS are documented to cause toxicity and where effects are lacking are described. Discrepancies exist in both human and animal studies and are likely attributable to human geographical contamination, developmental status, duration of exposure, and PFAS chemical identity. Similarly, in animal investigations, the model used, exposure paradigm, and developmental status of the female are important and vary widely in documented studies. Taken together, support for PFAS as reproductive and developmental toxicants exists, although the disparity in study conditions and human exposures contribute to the variation in effects noted.
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Affiliation(s)
| | | | - Aileen F. Keating
- Department of Animal Science, Iowa State University, Ames, IA 50011, USA
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Wang W, Hong X, Zhao F, Wu J, Wang B. The effects of perfluoroalkyl and polyfluoroalkyl substances on female fertility: A systematic review and meta-analysis. ENVIRONMENTAL RESEARCH 2023; 216:114718. [PMID: 36334833 DOI: 10.1016/j.envres.2022.114718] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 10/21/2022] [Accepted: 10/31/2022] [Indexed: 06/16/2023]
Abstract
OBJECTIVE The reproductive toxicity of perfluoroalkyl and polyfluoroalkyl substances (PFAS) has been verified in both animal and in vitro experiments, however, the association between PFAS and female fertility remains contradictory in population studies. Therefore, in this systematic review and meta-analysis, we evaluated the effects of PFAS on female fertility based on population evidence. METHODS Electronic searches of the Web of Science, PubMed, The Cochrane Library, and Embase databases were conducted (from inception to March 2022) to collect observational studies related to PFAS and female fertility. Two evaluators independently screened the literature, extracted information and evaluated the risk of bias for the included studies, meta-analysis was performed using R software. RESULTS A total of 5468 records were searched and 13 articles fully met the inclusion criteria. Meta-analysis showed that perfluorooctanoic acid (PFOA) exposure was negatively associated with the female fecundability odds ratio (FOR = 0.88, 95% confidence interval (Cl) [0.78; 0.98]) and positively associated with the odds ratio for infertility (OR = 1.33, 95%Cl [1.03; 1.73]). Perfluorooctane sulfonate (PFOS) exposure was negatively associated with the fecundability odds ratio (FOR = 0.94, 95% CI [0.90; 0.98]). Pooled effect values for perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), and perfluorohexane sulfonate (PFHxS) exposure did not find sufficient evidence for an association with female fertility. CONCLUSION Based on the evidence provided by the current study, increased levels of PFAS exposure are associated with reduced fertility in women, this was characterized by a reduction in fecundability odds ratio and an increase in odds ratio for infertility. This finding could partially explain the decline in female fertility and provide insight into risk assessment when manufacturing products containing PFAS.
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Affiliation(s)
- Wei Wang
- Key Laboratory of Environmental Medicine and Engineering of Ministry of Education, Department of Epidemiology and Health Statistics, School of Public Health, Southeast University, Nanjing, Jiangsu, China
| | - Xiang Hong
- Key Laboratory of Environmental Medicine and Engineering of Ministry of Education, Department of Epidemiology and Health Statistics, School of Public Health, Southeast University, Nanjing, Jiangsu, China
| | - Fanqi Zhao
- Key Laboratory of Environmental Medicine and Engineering of Ministry of Education, Department of Epidemiology and Health Statistics, School of Public Health, Southeast University, Nanjing, Jiangsu, China
| | - Jingying Wu
- Key Laboratory of Environmental Medicine and Engineering of Ministry of Education, Department of Epidemiology and Health Statistics, School of Public Health, Southeast University, Nanjing, Jiangsu, China
| | - Bei Wang
- Key Laboratory of Environmental Medicine and Engineering of Ministry of Education, Department of Epidemiology and Health Statistics, School of Public Health, Southeast University, Nanjing, Jiangsu, China.
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Luo K, Liu X, Zhou W, Nian M, Qiu W, Yang Y, Zhang J. Preconception exposure to perfluoroalkyl and polyfluoroalkyl substances and couple fecundity: A couple-based exploration. ENVIRONMENT INTERNATIONAL 2022; 170:107567. [PMID: 36240624 DOI: 10.1016/j.envint.2022.107567] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 09/09/2022] [Accepted: 10/04/2022] [Indexed: 06/16/2023]
Abstract
Numerous studies have examined the adverse health effects of perfluoroalkyl and polyfluoroalkyl substances (PFAS) but it remains unclear whether preconception exposure to PFAS affects couple fecundity. This prospective preconception cohort study with 936 Chinese couples aimed to comprehensively assess the effects of PFAS on couple fecundity [measured by the time to pregnancy (TTP)] and infertility (i.e., TTP > 12 menstrual cycles) with a focus on the effects of partner-specific exposure and joint-effects of couple-based exposure. Twenty-five PFAS were quantified in plasma from each partner, including seven branched isomers, two chlorinated polyfluoroalkyl ether sulfonic acids, four emerging PFAS replacements [i.e., 6:2 fluorotelomer phosphate diester (6:2 diPAP) and three short-chain alternatives: perfluoro-n-butanoicacid, perfluorobutane sulfonate and perfluoroheptanoic acid (PFHpA)]. Using a two-phase regression approach composed of elastic net regression and principal component analysis, we found that exposure to 6:2 diPAP and PFHpA rather than legacy PFAS in women and the couple-based exposure patterns characterized by high level of female 6:2 diPAP were significantly associated with reduced couple fecundity, which was independent of the adjustment of co-exposed PFAS homogenous from both partners. For example, a ln unit increase in female 6:2 diPAP was associated with 15 % [fecundity odds ratio (FOR) = 0.85, 95 %CI: 0.76, 0.96)] lower odds of couple fecundability (i.e., longer TTP) and 45 % increased risk of infertility [OR = 1.45 (95 %CI: 1.16, 1.81)], respectively. While most PFAS in men were not associated with couple fecundity, certain PFAS (e.g., perfluorohexane sulfonic acid) in men were negatively associated with infertility risk. However, the combined effects of PFAS mixture in couples were nonsignificant. Our findings suggest that PFAS in men and women may exert different impacts on couple fecundity. Preconception exposure to 6:2 diPAP and PFHpA in women may have the potential to impair couple fecundity.
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Affiliation(s)
- Kai Luo
- Ministry of Education-Shanghai Key Laboratory of Children's Environmental Health, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China; School of Public Health, Shanghai Jiao Tong University, Shanghai 200025, China
| | - Xiaotu Liu
- School of Environment, Guangzhou Key Laboratory of Environmental Exposure and Health, and Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou 510632, China
| | - Wei Zhou
- Center for Reproductive Medicine, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, China; Key Laboratory of Reproductive Endocrinology of Ministry of Education, Shandong University, Jinan, Shandong 250012, China
| | - Min Nian
- Ministry of Education-Shanghai Key Laboratory of Children's Environmental Health, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China; School of Public Health, Shanghai Jiao Tong University, Shanghai 200025, China
| | - Wei Qiu
- Ministry of Education-Shanghai Key Laboratory of Children's Environmental Health, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China; School of Public Health, Shanghai Jiao Tong University, Shanghai 200025, China
| | - Yan Yang
- School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, China; Jieyang Branch of Chemistry and Chemical Engineering Guangdong Laboratory, Jieyang 515200, Guangdong, China; Synergy Innovation Institute of GDUT, Shantou 515041, China.
| | - Jun Zhang
- Ministry of Education-Shanghai Key Laboratory of Children's Environmental Health, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China; School of Public Health, Shanghai Jiao Tong University, Shanghai 200025, China.
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Land KL, Miller FG, Fugate AC, Hannon PR. The effects of endocrine-disrupting chemicals on ovarian- and ovulation-related fertility outcomes. Mol Reprod Dev 2022; 89:608-631. [PMID: 36580349 PMCID: PMC10100123 DOI: 10.1002/mrd.23652] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 11/03/2022] [Accepted: 11/06/2022] [Indexed: 11/21/2022]
Abstract
Exposure to endocrine-disrupting chemicals (EDCs) is unavoidable, which represents a public health concern given the ability of EDCs to target the ovary. However, there is a large gap in the knowledge about the impact of EDCs on ovarian function, including the process of ovulation. Defects in ovulation are the leading cause of infertility in women, and EDC exposures are contributing to the prevalence of infertility. Thus, investigating the effects of EDCs on the ovary and ovulation is an emerging area for research and is the focus of this review. The effects of EDCs on gametogenesis, uterine function, embryonic development, and other aspects of fertility are not addressed to focus on ovarian- and ovulation-related fertility issues. Herein, findings from epidemiological and basic science studies are summarized for several EDCs, including phthalates, bisphenols, per- and poly-fluoroalkyl substances, flame retardants, parabens, and triclosan. Epidemiological literature suggests that exposure is associated with impaired fecundity and in vitro fertilization outcomes (decreased egg yield, pregnancies, and births), while basic science literature reports altered ovarian follicle and corpora lutea numbers, altered hormone levels, and impaired ovulatory processes. Future directions include identification of the mechanisms by which EDCs disrupt ovulation leading to infertility, especially in women.
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Affiliation(s)
- Katie L. Land
- Department of Obstetrics & Gynecology, College of MedicineUniversity of KentuckyLexingtonKentuckyUSA
| | - Frances G. Miller
- Department of Obstetrics & Gynecology, College of MedicineUniversity of KentuckyLexingtonKentuckyUSA
| | - Ava C. Fugate
- Department of Obstetrics & Gynecology, College of MedicineUniversity of KentuckyLexingtonKentuckyUSA
| | - Patrick R. Hannon
- Department of Obstetrics & Gynecology, College of MedicineUniversity of KentuckyLexingtonKentuckyUSA
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Li J, Pinkard BR, Wang S, Novosselov IV. Review: Hydrothermal treatment of per- and polyfluoroalkyl substances (PFAS). CHEMOSPHERE 2022; 307:135888. [PMID: 35931254 DOI: 10.1016/j.chemosphere.2022.135888] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 07/14/2022] [Accepted: 07/28/2022] [Indexed: 06/15/2023]
Abstract
PER: and polyfluoroalkyl substances (PFAS) are a concerning and unique class of environmentally persistent contaminants with biotoxic effects. Decades of PFAS discharge into water and soil resulted in PFAS bioaccumulation in plants, animals, and humans. PFAS are very stable, and their treatment has become a global environmental challenge. Significant efforts have been made to achieve efficient and complete PFAS mineralization using existing and emerging technologies. Hydrothermal treatments in subcritical and supercritical water have emerged as promising end-of-life PFAS destruction technologies, attracting the attention of scholars, industry, and key stakeholders. This paper reviews the state-of-the-art research on the behavior of PFAS, PFAS precursors, PFAS alternatives, and PFAS-containing waste in hydrothermal processes, including the destruction and defluorination efficiency, the proposed reaction mechanisms, and the environmental impact of these treatments. Scientific literature shows that >99% degradation and >60% defluorination of PFAS can be achieved through subcritical and supercritical water processing. The limitations of current research are evaluated, special considerations are given to the challenges of technology maturation and scale-up from laboratory studies to large-scale industrial application, and potential future technological developments are proposed.
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Affiliation(s)
- Jianna Li
- University of Washington, Mechanical Engineering Department, Seattle, WA 98195, USA; Key Laboratory of Thermo-Fluid Science and Engineering of MOE, School of Energy and Power Engineering, Xi'an Jiaotong University, 28 Xianning West Road, Xi'an 710049, China
| | - Brian R Pinkard
- University of Washington, Mechanical Engineering Department, Seattle, WA 98195, USA; Aquagga, Inc., Tacoma, WA 98421, USA
| | - Shuzhong Wang
- Key Laboratory of Thermo-Fluid Science and Engineering of MOE, School of Energy and Power Engineering, Xi'an Jiaotong University, 28 Xianning West Road, Xi'an 710049, China
| | - Igor V Novosselov
- University of Washington, Mechanical Engineering Department, Seattle, WA 98195, USA.
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Green MP, Harvey AJ, Finger BJ, Tarulli GA. Endocrine disrupting chemicals: Impacts on human fertility and fecundity during the peri-conception period. ENVIRONMENTAL RESEARCH 2021; 194:110694. [PMID: 33385395 DOI: 10.1016/j.envres.2020.110694] [Citation(s) in RCA: 59] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 12/24/2020] [Accepted: 12/25/2020] [Indexed: 05/08/2023]
Abstract
It is becoming increasingly difficult to avoid exposure to man-made endocrine disrupting chemicals (EDCs) and environmental toxicants. This escalating yet constant exposure is postulated to partially explain the concurrent decline in human fertility that has occurred over the last 50 years. Controversy however remains as to whether associations exist, with conflicting findings commonly reported for all major EDC classes. The primary aim of this extensive work was to identify and review strong peer-reviewed evidence regarding the effects of environmentally-relevant EDC concentrations on adult male and female fertility during the critical periconception period on reproductive hormone concentrations, gamete and embryo characteristics, as well as the time to pregnancy in the general population. Secondly, to ascertain whether individuals or couples diagnosed as sub-fertile exhibit higher EDC or toxicant concentrations. Lastly, to highlight where little or no data exists that prevents strong associations being identified. From the greater than 1480 known EDCs, substantial evidence supports a negative association between exposure to phthalates, PCBs, PBDEs, pyrethroids, organochloride pesticides and male fertility and fecundity. Only moderate evidence exists for a negative association between BPA, PCBs, organochloride pesticides and female fertility and fecundity. Overall fewer studies were reported in women than men, with knowledge gaps generally evident for both sexes for all the major EDC classes, as well as a paucity of female fertility studies following exposure to parabens, triclosans, dioxins, PFAS, organophosphates and pyrethroids. Generally, sub-fertile individuals or couples exhibit higher EDC concentrations, endorsing a positive association between EDC exposure and sub-fertility. This review also discusses confounding and limiting factors that hamper our understanding of EDC exposures on fertility and fecundity. Finally, it highlights future research areas, as well as government, industry and social awareness strategies required to mitigate the negative effects of EDC and environmental toxicant exposure on human fertility and fecundity.
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Affiliation(s)
- Mark P Green
- School of BioSciences, University of Melbourne, Melbourne, VIC, Australia.
| | - Alexandra J Harvey
- School of BioSciences, University of Melbourne, Melbourne, VIC, Australia
| | - Bethany J Finger
- School of BioSciences, University of Melbourne, Melbourne, VIC, Australia
| | - Gerard A Tarulli
- School of BioSciences, University of Melbourne, Melbourne, VIC, Australia
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Kahn LG, Harley KG, Siegel EL, Zhu Y, Factor-Litvak P, Porucznik CA, Klein-Fedyshin M, Hipwell AE. Persistent organic pollutants and couple fecundability: a systematic review. Hum Reprod Update 2021; 27:339-366. [PMID: 33147335 PMCID: PMC7903116 DOI: 10.1093/humupd/dmaa037] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 07/22/2020] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Despite increasing regulation, exposure to persistent organic pollutants (POPs) remains a serious public health concern due to their accumulation in the environment and ability to biomagnify up the food chain. POPs are associated with endocrine-disrupting effects including adverse reproductive outcomes that could affect fecundability, i.e. the capacity to conceive a pregnancy, quantified as time to pregnancy (TTP). OBJECTIVE AND RATIONALE Results of epidemiologic studies that examine the impact of various chemical classes of POPs on TTP have not been synthesised. We undertook a systematic review to summarise the strength of evidence for associations of four common groups of POPs with couple fecundability and to identify gaps and limitations in the literature in order to inform policy decisions and future research. SEARCH METHODS We performed an electronic search of literature published between 1 January 2007 and 6 August 2019 in MEDLINE, EMBASE.com, Global Health, DART/TOXLINE and POPLINE. We included empirical research papers that examined human exposure to organochlorine (OC) pesticides, brominated flame retardants, polychlorinated organic compounds and/or per- and polyfluoroalkyl substances (PFAS) and considered TTP or fecundability as an outcome. Standardised forms for screening, data extraction and study quality were developed using DistillerSR software, and all reviews were completed in duplicate. We used the Newcastle-Ottawa Scale to assess risk of bias and devised additional quality metrics based on specific methodological features of fecundability studies. OUTCOMES The search returned 4573 articles, and 28 papers from 19 different studies met inclusion criteria. Among them, four studies measured TTP prospectively, three had data on participants' prenatal exposure, three examined associations in both male and female partners and one focused exclusively on males. Analyses varied widely in terms of exposure characterisation, precluding a meta-analytic approach. Evidence was strongest for adverse associations of female exposure to polychlorinated biphenyls with TTP, with some additional support for associations of female exposure to polybrominated diphenyl ethers and PFAS with longer TTP. Our review provided little or no support for associations between female exposure to OC pesticides or male exposure to any of the POP groups and TTP. WIDER IMPLICATIONS Evidence suggests that female exposure to at least some POPs may reduce fecundability. Although many of these chemicals are no longer in production, they are still detectable in human biosamples because of their persistence in the environment. Replacement chemicals that are being introduced as older ones are restricted may have similar reproductive consequences. Future studies should examine these newer POPs, assess interactions between POPs and other chemical and non-chemical exposures, investigate how POPs are distributed in and metabolised by the human body and focus on populations that may be disproportionately exposed.
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Affiliation(s)
- Linda G Kahn
- Department of Pediatrics, New York University Grossman School of Medicine, New York, NY 10016 USA
| | - Kim G Harley
- Center for Environmental Research and Children’s Health, University of California Berkeley, Berkley, CA 94720, USA
| | - Eva L Siegel
- Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, NY 10032, USA
| | - Yeyi Zhu
- Division of Research, Kaiser Permanente Northern California, Oakland, CA 94612, USA
| | - Pam Factor-Litvak
- Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, NY 10032, USA
| | - Christina A Porucznik
- Department of Family and Preventive Medicine, School of Medicine, University of Utah, Salt Lake City, UT 84108, USA
| | | | - Alison E Hipwell
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA 15213, USA
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Dasgupta S, Reddam A, Liu Z, Liu J, Volz DC. High-content screening in zebrafish identifies perfluorooctanesulfonamide as a potent developmental toxicant. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 256:113550. [PMID: 31706782 PMCID: PMC6920544 DOI: 10.1016/j.envpol.2019.113550] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2019] [Revised: 10/27/2019] [Accepted: 10/30/2019] [Indexed: 05/20/2023]
Abstract
Per- and polyfluoroalkyl substances (PFASs) have been used for decades within industrial processes and consumer products, resulting in frequent detection within the environment. Using zebrafish embryos, we screened 38 PFASs for developmental toxicity and revealed that perfluorooctanesulfonamide (PFOSA) was the most potent developmental toxicant, resulting in elevated mortality and developmental abnormalities following exposure from 6 to 24 h post fertilization (hpf) and 6 to 72 hpf. PFOSA resulted in a concentration-dependent increase in mortality and abnormalities, with surviving embryos exhibiting a >12-h delay in development at 24 hpf. Exposures initiated at 0.75 hpf also resulted in a concentration-dependent delay in epiboly, although these effects were not driven by a specific sensitive window of development. We relied on mRNA-sequencing to identify the potential association of PFOSA-induced developmental delays with impacts on the embryonic transcriptome. Relative to stage-matched vehicle controls, these data revealed that pathways related to hepatotoxicity and lipid transport were disrupted in embryos exposed to PFOSA from 0.75 to 14 hpf and 0.75 to 24 hpf. Therefore, we measured liver area as well as neutral lipids in 128-hpf embryos exposed to vehicle (0.1% DMSO) or PFOSA from 0.75 to 24 hpf and clean water from 24 to 128 hpf, and showed that PFOSA exposure from 0.75 to 24 hpf resulted in a decrease in liver area and increase in yolk sac neutral lipids at 128 hpf. Overall, our findings show that early exposure to PFOSA adversely impacts embryogenesis, an effect that may lead to altered lipid transport and liver development.
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Affiliation(s)
- Subham Dasgupta
- Department of Environmental Sciences, University of California, Riverside, CA, USA
| | - Aalekhya Reddam
- Department of Environmental Sciences, University of California, Riverside, CA, USA; Environmental Toxicology Graduate Program, University of California, Riverside, CA, USA
| | - Zekun Liu
- Department of Chemical and Environmental Engineering, University of California, Riverside, CA, USA
| | - Jinyong Liu
- Department of Chemical and Environmental Engineering, University of California, Riverside, CA, USA
| | - David C Volz
- Department of Environmental Sciences, University of California, Riverside, CA, USA.
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Bach C, Matthiesen N, Olsen J, Henriksen T. Conditioning on Parity in Studies of Perfluoroalkyl Acids and Time to Pregnancy: An Example from the Danish National Birth Cohort. ENVIRONMENTAL HEALTH PERSPECTIVES 2018; 126:117003. [PMID: 30417653 PMCID: PMC6371644 DOI: 10.1289/ehp1493] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
BACKGROUND Previous studies have investigated the associations between perfluoroalkyl acids (PFAAs) in women and time to pregnancy (TTP). Inconsistent results may be explained by differences in conditioning on parity. OBJECTIVES We used causal directed acyclic graphs to illustrate potential confounding related to previous pregnancies and exposure measurement error due to differences in the interpregnancy interval in pregnancy-based studies that include parous women. We exemplified the potential importance of these issues using data from the Danish National Birth Cohort. METHODS We used discrete time survival models to estimate associations between maternal plasma PFAAs in early pregnancy and TTP in 638 nulliparous and 613 parous women. RESULTS PFAA quartiles were not associated with the TTP in nulliparous women. In parous women, higher PFAA quartiles were associated with longer TTP. The strongest associations were estimated for perfluorohexane sulfonate and perfluorooctane sulfonate. PFAA concentrations were higher in women with longer interpregnancy intervals. Accounting for the interpregnancy interval attenuated the estimated associations. CONCLUSIONS Associations between PFAAs and TTP in parous women may be biased by confounders related to previous pregnancies and exposure measurement error. To avoid these biases, studies that include parous women may need to condition on a) common causes of PFAAs and the TTP in the index pregnancy, b) previous births (a descendant of a collider), c) PFAA levels or common causes of PFAA levels and the TTP in the previous pregnancy (to alleviate collider stratification bias caused by conditioning on previous births), and d) the interpregnancy interval (in pregnancy-based studies). Alternatives would be to restrict studies to nulliparous women or to use toxicokinetic modeling to correct exposure estimates in parous women. These recommendations may be extended to studies of other chemicals with similar toxicokinetic properties. https://doi.org/10.1289/EHP1493.
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Affiliation(s)
- Cathrine Bach
- Department of Pediatrics and Adolescent Medicine, Viborg Regional Hospital, Viborg, Denmark
- Department of Pediatrics and Adolescent Medicine, Aarhus University Hospital, Aarhus, Denmark
- Perinatal Epidemiology Research Unit, Aarhus University Hospital, Aarhus, Denmark
| | - Niels Matthiesen
- Department of Pediatrics and Adolescent Medicine, Aarhus University Hospital, Aarhus, Denmark
- Perinatal Epidemiology Research Unit, Aarhus University Hospital, Aarhus, Denmark
- Department of Pediatrics and Adolescent Medicine, Randers Regional Hospital, Randers, Denmark
| | - Jørn Olsen
- Section for Epidemiology, Department of Public Health, Aarhus University, Aarhus, Denmark
- Department of Epidemiology, Fielding School of Public Health, University of California, Los Angeles, Los Angeles, California, USA
- Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark
| | - Tine Henriksen
- Department of Pediatrics and Adolescent Medicine, Aarhus University Hospital, Aarhus, Denmark
- Perinatal Epidemiology Research Unit, Aarhus University Hospital, Aarhus, Denmark
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Zhao S, Zhou T, Wang B, Zhu L, Chen M, Li D, Yang L. Different biotransformation behaviors of perfluorooctane sulfonamide in wheat (Triticum aestivum L.) from earthworms (Eisenia fetida). JOURNAL OF HAZARDOUS MATERIALS 2018; 346:191-198. [PMID: 29275108 DOI: 10.1016/j.jhazmat.2017.12.018] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2017] [Revised: 12/05/2017] [Accepted: 12/06/2017] [Indexed: 06/07/2023]
Abstract
Perfluorooctane sulfonamide (PFOSA) is a precursor of perfluorooctane sulfonic acid (PFOS) and can be broken down to PFOS in environment and biota. In the present work, PFOSA was spiked in soil and its biodegradation in soil, uptake and metabolism in wheat (Triticum aestivum L.) and earthworms (Eisenia fetida) were investigated. The results indicated that PFOSA could be biodegraded to highly stable PFOS, which has the same perfluorinated carbon chain length as PFOSA, by microbes in soil. PFOSA could be taken up by wheat root and earthworm from soil with higher bioaccumulation ability than PFOS. In both wheat and earthworms, PFOSA also degraded to PFOS. However, other shorter-chain perfluoroalkane sulfonates (PFSAs), including perfluorohexane sulfonate (PFHxS) and perfluorobutane sulfonate (PFBS), were observed in wheat, but not in soil and earthworms, suggesting that wheat displayed distinctly different degradation mechanisms to PFOSA from soil microbes and earthworms.
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Affiliation(s)
- Shuyan Zhao
- Key Laboratory of Industrial Ecology and Environmental Engineering, School of Food and Environment, Dalian University of Technology, Panjin, Liaoning 124221, PR China
| | - Tao Zhou
- Key Laboratory of Industrial Ecology and Environmental Engineering, School of Food and Environment, Dalian University of Technology, Panjin, Liaoning 124221, PR China
| | - Bohui Wang
- Key Laboratory of Industrial Ecology and Environmental Engineering, School of Food and Environment, Dalian University of Technology, Panjin, Liaoning 124221, PR China
| | - Lingyan Zhu
- Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, PR China; College of Natural Resources and Environment, Northwest A&F University, Yangling, Shanxi 712100, PR China.
| | - Meng Chen
- 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
| | - Dandan Li
- 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
| | - Liping Yang
- 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
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