Early life exposure to per- and polyfluoroalkyl substances (PFAS) and latent health outcomes: A review including the placenta as a target tissue and possible driver of peri- and postnatal effects.
Blake Bevin E,Fenton Suzanne E
Per- and polyfluoroalkyl substances (PFAS) are ubiquitous drinking water contaminants of concern due to mounting evidence implicating adverse health outcomes associated with exposure, including reduced kidney function, metabolic syndrome, thyroid disruption, and adverse pregnancy outcomes. PFAS have been produced in the U.S. since the 1940s and now encompass a growing chemical family comprised of diverse chemical moieties, yet the toxicological effects have been studied for relatively few compounds. Critically, exposures to some PFAS in utero are associated with adverse outcomes for both mother and offspring, such as hypertensive disorders of pregnancy (HDP), including preeclampsia, and low birth weight. Given the relationship between HDP, placental dysfunction, adverse health outcomes, and increased risk for chronic diseases in adulthood, the role of both developmental and lifelong exposure to PFAS likely contributes to disease risk in complex ways. Here, evidence for the role of some PFAS in disrupted thyroid function, kidney disease, and metabolic syndrome is synthesized with an emphasis on the placenta as a critical yet understudied target of PFAS and programming agent of adult disease. Future research efforts must continue to fill the knowledge gap between placental susceptibility to environmental exposures like PFAS, subsequent perinatal health risks for both mother and child, and latent health effects in adult offspring.
Association between Prenatal Exposure to PFAS and Fetal Sex Hormones: Are the Short-Chain PFAS Safer?
Nian Min,Luo Kai,Luo Fei,Aimuzi Ruxianguli,Huo Xiaona,Chen Qian,Tian Ying,Zhang Jun
Environmental science & technology
Epidemiologic evidence regarding the effects of in utero exposure to per- and polyfluoroalkyl substances (PFAS), particularly short-chain PFAS, on fetal reproductive hormones is limited and inconsistent. This study aimed to assess the relationship between maternal PFAS exposure and fetal reproductive hormones. A total of 752 mother-infant pairs who were recruited in the Shanghai Birth Cohort Study between 2013 and 2016 were selected. We quantified 10 PFAS, including two short-chain PFAS congeners (perfluorobutanesulfonate, PFBS and perfluoroheptanoic acid, PFHpA), in maternal blood plasma in early pregnancy. Dehydroepiandrosterone sulfate (DHEA-S), sex hormone-binding globulin (SHBG), luteinizing hormone (LH), follicle-stimulating hormone (FSH) and total testosterone (TT) were measured in the umbilical cord blood using chemiluminescence kits. Free androgen index (FAI) was calculated by TT divided by SHBG. Multiple linear regression found that one ln-unit increase in maternal PFBS was associated with decreases in FSH (-0.159; 95% CI: -0.290, -0.029), LH (-0.113; 95% CI: -0.221, -0.004), and FAI (-0.009; 95% CI: -0.017, -0.001). In addition, PFHpA showed negative associations with LH (-0.154; 95% CI: -0.297, -0.011) and FAI (-0.008; 95% CI: -0.014, -0.002). When PFAS were analyzed in quartiles, significant negative associations were observed between PFBS and FSH, and between PFHpA and FAI. Overall, prenatal exposure to PFBS and PFHpA was associated with the disturbance of fetal gonadotropins as well as free androgen level in this prospective cohort, suggesting that the reproductive toxicity of short-chain PFAS may not be neglected.
PFAS Exposure Pathways for Humans and Wildlife: A Synthesis of Current Knowledge and Key Gaps in Understanding.
De Silva Amila O,Armitage James M,Bruton Thomas A,Dassuncao Clifton,Heiger-Bernays Wendy,Hu Xindi C,Kärrman Anna,Kelly Barry,Ng Carla,Robuck Anna,Sun Mei,Webster Thomas F,Sunderland Elsie M
Environmental toxicology and chemistry
We synthesize current understanding of the magnitudes and methods for assessing human and wildlife exposures to poly- and perfluoroalkyl substances (PFAS). Most human exposure assessments have focused on 2 to 5 legacy PFAS, and wildlife assessments are typically limited to targeted PFAS (up to ~30 substances). However, shifts in chemical production are occurring rapidly, and targeted methods for detecting PFAS have not kept pace with these changes. Total fluorine measurements complemented by suspect screening using high-resolution mass spectrometry are thus emerging as essential tools for PFAS exposure assessment. Such methods enable researchers to better understand contributions from precursor compounds that degrade into terminal perfluoroalkyl acids. Available data suggest that diet is the major human exposure pathway for some PFAS, but there is large variability across populations and PFAS compounds. Additional data on total fluorine in exposure media and the fraction of unidentified organofluorine are needed. Drinking water has been established as the major exposure source in contaminated communities. As water supplies are remediated, for the general population, exposures from dust, personal care products, indoor environments, and other sources may be more important. A major challenge for exposure assessments is the lack of statistically representative population surveys. For wildlife, bioaccumulation processes differ substantially between PFAS and neutral lipophilic organic compounds, prompting a reevaluation of traditional bioaccumulation metrics. There is evidence that both phospholipids and proteins are important for the tissue partitioning and accumulation of PFAS. New mechanistic models for PFAS bioaccumulation are being developed that will assist in wildlife risk evaluations. Environ Toxicol Chem 2021;40:631-657. © 2020 SETAC.
Exposure, health effects, sensing, and remediation of the emerging PFAS contaminants - Scientific challenges and potential research directions.
Bell Erin M,De Guise Sylvain,McCutcheon Jeffrey R,Lei Yu,Levin Milton,Li Baikun,Rusling James F,Lawrence David A,Cavallari Jennifer M,O'Connell Caitlin,Javidi Bethany,Wang Xinyu,Ryu Heejeong
The Science of the total environment
Per- and polyfluoroalkyl substances (PFAS) make up a large group of persistent anthropogenic chemicals which are difficult to degrade and/or destroy. PFAS are an emerging class of contaminants, but little is known about the long-term health effects related to exposure. In addition, technologies to identify levels of contamination in the environment and to remediate contaminated sites are currently inadequate. In this opinion-type discussion paper, a team of researchers from the University of Connecticut and the University at Albany discuss the scientific challenges in their specific but intertwined PFAS research areas, including rapid and low-cost detection, energy-saving remediation, the role of T helper cells in immunotoxicity, and the biochemical and molecular effects of PFAS among community residents with measurable PFAS concentrations. Potential research directions that may be employed to address those challenges and improve the understanding of sensing, remediation, exposure to, and health effects of PFAS are then presented. We hope our account of emerging problems related to PFAS contamination will encourage a broad range of scientific experts to bring these research initiatives addressing PFAS into play on a national scale.