PFAS Environmental Pollution and Antioxidant Responses: An Overview of the Impact on Human Field

Exposure to PFOS, PFBS, PFOA and PFBA impairs cell cycle progression in bovine brain (Bos taurus) endothelial cells

Perfluoroalkylated substances (PFAS) are the large class of synthetic chemicals that persist in the environment and bioaccumulate in different tissues including the brain, inducing blood brain barrier (BBB) disruption. In this study, we assessed cytotoxicity of PFAS in a bovine brain endothelial cell line by exposing the cells to increasing concentrations (0.01, 0.1, 1, 10, and 100 μM) of perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), perfluorobutane sulfonic acid (PFBS), perfluorobutanoic acid (PFBA) and perfluoro ([5-methoxy-1,3-dioxolan-4-yl]oxy) acetic acid (C6O4). Cell viability, cell cycle profiling and the apoptotic potential were then analyzed. Cells were categorized by grouping nuclei into G0 + G1, Synthesis (S) and Mitotic phases (M), nuclei showing characteristics of senescence and nuclear fragments. By combining high throughput screening with cell nuclei counting for group, we determined the relationship between the dose-response effect of PFAS and their proliferative potential. Our results showed that PFOS decreased the number of cells in S and M phase. PFBS reduced the number of cells in M phase, decreased the senescence phenotype and increased the number of fragment nuclei. PFOA enhanced the number of cells nuclei in S and M phase. The PFBA enhanced the number of nuclei in G0 + G1, S and M phase. C6O4 did not show significant variation under any of the experimental conditions tested. We did not find significant changes in terms of cell viability assay. This bovine endothelial cell line provides an alternative model for studying the mechanisms involved in the decrease of BBB integrity due to PFAS accumulation in a large mammal with large brain.

Assessing the Impact of Serum Per- and Polyfluoroalkyl Substance Concentrations on Immune Function in an Industrialized Region of China

This study investigates the presence and health implications of per- and polyfluoroalkyl substances (PFAS) in human serum samples collected from white-collar workers in an industrialized region of China. Our research offers fresh insights into the underexplored area of nonoccupational PFAS exposure among white-collar workers, shedding light on health risks linked to industrial PFAS pollution. Seven PFAS compounds were measured. Perfluorooctanoic acid (PFOA) and perfluorooctanesulfonate (PFOS) emerged as predominant pollutants, with Σ7PFAS concentrations averaging 65.486 ng/mL. Gender differences showed higher serum Σ7PFAS levels in males, and age-related analyses suggested PFAS accumulation over time, with higher concentrations in older groups. Additionally, significant correlations were found between PFAS concentrations and biomarkers of oxidative stress and immune interference, specifically malondialdehyde (MDA) and immunoglobulin M (IgM), indicating that PFAS exposure may contribute to oxidative damage and potential immunosuppression. The study highlights regional and international variations in PFAS serum concentrations, underscoring the influence of industrial activities on PFAS exposure and expanding on the established links between PFAS exposure and health outcomes. These findings call for targeted strategies to mitigate PFAS exposure in high-risk regions and warrant further research on PFAS health impacts, especially in regard to immune interference.

Dietary protein deficiency exacerbates perfluorohexane sulfonate (PFHxS)-induced reproductive abnormalities and metabolic disruptions in female rats

Perfluorohexane sulfonate (PFHxS) is a persistent environmental contaminant linked with several health implications. Humans are exposed to PFHxS mainly through ingestion. Studies reported that a diet deficient in essential nutrients may have confounding effect on toxicity outcome of chemicals. We evaluated the potential impact of PFHxS exposure on reproductive damage in animals maintained on the diet deficient in protein. Female Wistar rats (n=6) were divided as controls and treatment groups (5 ppm and 25 ppm PFHxS, protein deficient, protein deficient +5 ppm PFHxS and protein deficient +25 ppm PFHxS). Chronic PFHxS exposure disrupted the estrous cycle with an increased duration of the diestrus stage at 25 ppm and protein deficient +25 ppm PFHxS showing 55.56% and 78.77% disorder, respectively. There was a significant elevation (P<0.01) in LH/FSH ratio and reduction in testosterone (P<0.01), estradiol (P<0.01), and progesterone (P<0.001) in protein deficient +25 ppm PFHxS group. A high order of increase in lipid profile parameters was found in protein deficient +25 ppm PFHxS group. However, high-density lipoprotein decreased in this group. Protein deficient +25 ppm PFHxS group animals also revealed high level of oxidative stress. Histopathological findings revealed the presence of cystic follicles and theca cell degeneration in ovaries in protein deficient +25 ppm PFHxS group with a significant decreased (P<0.01) in the myometrium and endometrial area of uterus. The combined effect of protein deficiency and PFHxS exposure caused a greater reprotoxicity compared to either factor alone implying an increased vulnerability of reproductive function in malnourished populations to environmental contaminants.

Assessment of per- and polyfluoroalkyl substances (PFAS) exposure and associations with oxidative stress biomarkers among pregnant women from the PROTECT cohort

INTRODUCTION

Per- and polyfluoroalkyl substances (PFAS) are synthetic chemicals linked with adverse pregnancy outcomes, yet they remain understudied in Puerto Rico. Moreover, underlying biological mechanisms of PFAS are not fully understood, although oxidative stress and inflammation are suspected pathways.

OBJECTIVES

We aimed to characterize PFAS exposure among pregnant women in Puerto Rico and examine associations between early to mid-pregnancy PFAS concentrations and repeated measures of oxidative stress biomarkers.

METHODS

This study included 434 participants enrolled in the PROTECT birth cohort. We analyzed serum samples (∼18 weeks of gestation) for nine PFAS, while urinary oxidative stress biomarkers [8-isoprostaglandin F2α (8-IsoP), its metabolite (IsoP-M), and prostaglandin F₂α (PGF2α)] were measured up to three times during pregnancy. We examined associations between each PFAS and oxidative stress biomarker using linear mixed effects regression models and multivariable regression analyses, adjusting for maternal demographic, socioeconomic, and study-related factors.

RESULTS

PFOS, PFNA, PFHxS, and PFOA were detected in over 50 % of participants, with PFOS being the most dominant. The majority of participants had total PFAS levels above 2 ng/mL. In repeated measures analyses, an interquartile range increase in PFHxS was associated with a 5.35 % (95 % CI: 0.12, 10.86) rise in IsoP-M levels. In categorical analyses, moderate levels of PFOS and PFNA were positively associated with PGF2α, while higher PFDeA was suggestively linked to 8-IsoP and IsoP-M.

CONCLUSIONS

Despite relatively modest levels compared to the U.S. NHANES, certain PFAS were positively linked with oxidative stress or inflammation, highlighting the need for broader investigations to examine PFAS-related alteration of inflammatory processes during pregnancy.

Estimation of species- and sex-specific PFAS pharmacokinetics in mice, rats, and non-human primates using a Bayesian hierarchical methodology

The carbon chain length, degree of fluorination, and functional group of per- and polyfluoroalkyl substances (PFAS) influences the bioaccumulation and half-lives of these substances in humans and laboratory animals. Pharmacokinetic (PK) studies using laboratory animals characterize the absorption, distribution, metabolism, and excretion (ADME) of a PFAS and can provide the underlying data for inter-species extrapolation to inform human pharmacokinetics. However, variations in ADME arise due to differences in protein binding and renal and hepatobiliary clearance mechanisms. In particular, sex- and species-specific differences in active transporter abundance and PFAS binding affinity challenge body weight-based extrapolation assumptions from animal models to human PK parameters. Because these protein-dependent changes in ADME do not always scale with species body weight, classic allometric scaling assumptions can fail to account for species-specific transporter-mediated clearance. In addition, study-dependent differences in pharmacokinetic modeling approaches and parameterization techniques can result in large differences among the PK parameters reported in the literature. To better quantify PFAS pharmacokinetics and characterize the underlying uncertainty, we implemented a Bayesian inference hierarchical model to estimate PFAS PK parameters for multiple species (mice, rats, and non-human primates) using numerous single-dose animal studies. Through an alternative parameterization of the one- and two-compartment models, this method improved parameter identifiability and allowed for the use of prior information on PFAS absorption rate, clearance, and volume of distribution. Using reported time-course concentration data, we estimated sex-specific clearance, volume of distribution, and half-life across mice, rats, and non-human primates using a consistent modeling methodology for eight PFAS: PFHxA, PFHxS, PFNA, PFDA, PFBS, PFBA, PFOA, and PFOS. The resulting comparison to available human data demonstrated that standard volume of distribution body-mass scaling (BW1) for PFAS generally agrees with reported human values while standard assumptions for allometric scaling of clearance (BW3/4) are not appropriate for most of the PFAS investigated in this study. In addition, we demonstrated that there may be considerable differences in clearance for PFAS in some species when comparing across different sexes and routes of exposure.

Towards Surface-Enhanced Homogeneous Catalysis: Tailoring the Enrichment of Metal Complexes at Ionic Liquid Surfaces

When talking about homogeneous catalyst systems, it has long been assumed that the system at hand consists of a transition metal complex in solution with the liquid interface representing the composition of the bulk solution. Now, in light of considerable developments in the study of metal complexes dissolved in ionic liquids with their negligible vapor pressures, more detailed studies of the composition at the liquid/gas interface became possible. These investigations revealed pronounced surface enrichment and segregation effects of high relevance for practical applications. This article reviews recent advancements in tailoring the interfacial composition of ionic liquid-based catalytic systems. A particular focus is dedicated to surface enrichment phenomena, and a variety of parameters are presented for deliberate control of the local concentration of the complexes at the surface, that is, the nature of the ligands, the bulk concentration, the temperature, and the nature of the IL solvent. As experimental methods, angle-resolved X-ray photoelectron spectroscopy (ARXPS) and vacuum-based pendant-drop surface tension measurements were applied. The reviewed results are intended to provide the basis for the advancement of catalytic systems with high surface areas, such as in supported ionic liquid phase (SILP) catalysis, where the interface design is directly interconnected with catalytic performance.

Early-pregnancy per- and polyfluoroalkyl substances and maternal post-pregnancy weight trajectory

OBJECTIVE

The objective of this study was to evaluate associations of early-pregnancy plasma per- and polyfluoroalkyl substances (PFAS) with maternal post-pregnancy weight trajectory parameters.

METHODS

We studied 1106 Project Viva participants with measures of early-pregnancy plasma concentrations of eight PFAS. We measured weight at in-person visits at 6 months and 3, 7, and 12 years after pregnancy and collected self-reported weight via annual questionnaires up to 17 years after pregnancy. Weight trajectory parameters were estimated via the Superimposition by Translation and Rotation model. We assessed individual and joint effects of PFAS with trajectory parameters using linear regression and Bayesian kernel machine regression (BKMR).

RESULTS

Perfluorooctane sulfonate (PFOS) concentrations were positively associated with weight trajectory magnitude in both linear regression (0.8 kg [95% CI: 0.1 to 1.4] per doubling of PFOS) and BKMR analyses (2.6 kg [95% CI: 1.4 to 3.8] per increase from 25th to 75th percentile of PFOS concentrations). Conversely, in BKMR analyses, perfluorononanoate was negatively associated with trajectory magnitude (-2.0 kg [95% CI: -2.9 to -1.1]). In stratified linear regression, older-aged participants had more pronounced positive associations of PFOS, perfluorooctanoate, and 2-(N-ethyl-perfluorooctane sulfonamido) acetate with weight trajectory velocity. No associations were observed with the overall PFAS mixture.

CONCLUSIONS

Select PFAS, assessed in pregnancy, may affect maternal weight trajectories spanning 17 years after pregnancy, especially for older-aged individuals.

The impact of endocrine disrupting chemicals on adrenal corticosteroids - A systematic review of epidemiological studies

BACKGROUND

The role of endocrine disrupting chemicals (EDCs) in the development of metabolic syndrome has gained increasing recognition in recent years. The underlying mechanisms are largely unresolved. Disruption of corticosteroid action and hypothalamic-pituitary-adrenal (HPA) axis are considered possible mechanisms.

OBJECTIVE

To summarise epidemiological studies investigating an association between EDC concentration and altered levels of corticosteroids and the adrenocorticotropic hormone (ACTH).

METHODS

Following the PRISMA guidelines, we searched PubMed and the Cochrane Library for epidemiological studies published from database inception until April 1st, 2024. Various groups of EDCs were evaluated with the prerequisite of direct measurement of the chemical, a metabolite, or biomarker.

RESULTS

We identified 2094 articles. After removing duplicates and screening, 27 studies were included. Studies focused predominantly on glucocorticoids (n = 26) compared to mineralocorticoids (n = 5) and ACTH (n = 2). The most studied EDCs were pesticides (n = 9) and phthalates (n = 8). Significant associations between the concentrations of specific EDCs and hormone levels were found in all but three studies. Only one study described an association between EDCs, and hormone concentration and metabolic features.

CONCLUSION

There is clear evidence for the impact of specific EDCs on plasma corticosteroid concentrations in different age groups worldwide, however, results varied according to EDC class, study population and study methodology. Further research combining EDC and hormone concentrations, and clinical features, complemented by experimental investigations to study cell mechanisms, is needed to gain holistic knowledge of EDCs' influence on glucocorticoid- and mineralocorticoid-related disorders.

Association and binding interaction between per- and polyfluoroalkyl substances and maternal thyroid hormones: A case study based on a prospective birth cohort in Wuxi, China

BACKGROUND AND AIM

The relationship between prenatal exposure to per- and polyfluoroalkyl substances (PFASs), a well-known endocrine disruptor, and thyroid hormones (THs) levels remains unclear. Therefore, this study aimed to investigate this relationship in a birth cohort during the second trimester.

METHOD

This prospective study included 562 pregnant women in the Wuxi Birth Cohort from 2019 to 2021 and quantified the serum concentrations of 23 PFASs and 5 THs. Multiple statistical models were used to assess the associations between individual or combined PFASs concentrations and THs, while molecular docking simulated the interactions between PFASs and four thyroid-related proteins.

RESULTS

The median concentration of ∑23PFASs was 71.91 ng/mL, with perfluorovaleric acid (PFPeA) (18.13 ng/mL) emerging as the predominant PFAS. Most PFASs were negatively associated with maternal free thyroxine (FT4) and thyroid-stimulating hormone (TSH) levels, whereas perfluorobutane sulfonate (PFBS) was positively correlated with TSH levels. A similar trend was observed in the weighted quantile sum (WQS) model, in which combined PFASs exposure was inversely associated with the FT4 and TSH levels. Molecular docking results showed that compared with TH natural ligand thyroxine (T4), perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), and 6:2 chlorinated polyfluorinated ether sulfonate (6:2 Cl- PFESA) exhibited relatively high binding affinity with thyroid-related proteins (-6.6 to -9.8 kcal/mol vs. T4: -5.6 to -8.6 kcal/mol). Furthermore, PFASs with medium chain lengths and sulfonic acid groups exhibited enhanced protein-binding properties.

CONCLUSION

PFASs exposure may affect THs homeostasis during pregnancy. Moreover, different types and concentrations of PFASs have different effects on THs in the maternal serum.

Per- and polyfluoroalkyl substances in environment and potential health impacts: Sources, remediation treatment and management, policy guidelines, destructive technologies, and techno-economic analysis

Per- and polyfluoroalkyl Substances (PFAS), also known as forever chemicals and ubiquitous persistence, pose significant public health challenges due to their potential toxicity, particularly in drinking water and soil contamination. However, PFAS occurrence and their concentrations in different environmental matrices vary globally, but factors influencing trends, transport, fate, toxicity, and interactions with co-contaminants remain largely unexplored. Therefore, this review critically examines the state-of-the-art worldwide PFAS sources, distribution, and pathways, and evaluates how PFASs are processed in wastewater treatment, generally, which causes severe problems with the quality and safety of drinking water. Importantly, the review also underscores health issues due to PFAS consumption and recent research trends on developing effective treatment strategies to manage PFAS contamination. Potential effects of PFAS were linked to urban land use and the proportion of wastewater effluent in streamflow. Besides, major emphasis was provided on challenges for conventional treatment, destructive technologies, environmental accumulation, precursor transformation, and cost-investment related to PFAS removal technologies. To combat PFAS contamination, this review proposes a framework that promotes the comprehensive identification of prevalent compounds, with a focus on their eradication through knowledge-based and targeted analysis. Additionally, it explores the ongoing debate surrounding PFAS laws and legal frameworks, offering ideas for enhancing contamination management. Lastly, this review provides a strategic plan for improving response and preparedness, serving as a foundation for addressing future environmental challenges and informing health risk assessments.

Sensitive and accurate determination of 32 PFAS in human serum using online SPE-UHPLC-HRMS

Per- and polyfluoroalkyl substances' (PFAS) extreme persistence has been linked to many adverse effects on human health including increased risk of certain cancers. This study presents the development and validation of a new, highly sensitive method for the quantification of 32 PFAS in human serum using online solid-phase extraction (SPE) coupled with ultra-high performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS). Legacy and emerging PFAS were targeted. Main steps of sample pretreatment include protein precipitation (PP), pellet rinsing, centrifugation, preconcentration through solvent evaporation, and online SPE using a weak anion-exchange polymeric sorbent. The PP and pellet-rinsing procedures were optimized through a comprehensive exploration of solvent combinations. Following this, a pretreatment that offers the best compromise for the targeted PFAS was identified using principal component analysis. The method demonstrated excellent linearity (R² = 0.977-0.997) with limits of quantification ranging from 8.9 to 27 ng/L, 5 to 15 times lower than previous methods. Precision (intraday 2.6-14.0 % and interday 1.3-11.0 % relative standard deviation) and accuracy (recoveries 72.7-106 %) were robust. The method was validated in accordance with ISO/IEC 17025 and successfully applied to five human serum samples, confirming its suitability for high-throughput profiling of PFAS in biomonitoring studies. This method is the first to use online SPE for the simultaneous determination of a broad range of PFAS, including ether congeners such as perfluoro(2-ethoxyethane) sulfonic acid and Nafion byproduct 2. Furthermore, control charts were employed to assess instrument performance during routine analysis and implement necessary actions.

Revealing hidden risks: in vitro analysis of PFAS hazards in Mytilus galloprovincialis gills and digestive gland

Per- and polyfluoroalkyl substances (PFAS) are synthetic chemicals known for their persistence and bioaccumulation, leading to widespread environmental contamination. Despite their recognised environmental risks, particularly to aquatic wildlife, including marine invertebrates, detailed impact studies are limited. PFAS can be categorised according to the length of the compound chain, with short-chain PFAS announced as a safer alternative to the more commonly used long-chain PFAS. However, recent evidence suggests that also short-chain PFAS pose significant environmental risks. The present study evaluated the adverse effects of six PFAS compounds-two short-chain (PFHxA, 6:2 FTA) and four long-chain (PFUnDA, PFDoA, PFTriDA, PFTeDA)- on the digestive gland and gills of mussels, Mytilus galloprovincialis, using in vitro assays. The results showed organ-specific responses: the digestive gland was more sensitive to PFHxA, with increased catalase activity and decreased total antioxidant capacity, and cellular damage was observed only at higher concentrations of PFTriDA. Gills were more affected by PFDoA and PFTeDA, with inhibited antioxidant enzyme activity and increased oxidative stress. PFHxA and PFTriDA also showed inhibition of acetylcholinesterase activity. 6:2 FTA had the lowest effects for both organs, while PFHxA was the most harmful. These findings underscore the need for thorough risk assessments of PFAS, considering both chain length and organ-specific effects.

Characterisation of the prdx4 gene in Squalius cephalus and its role in freshwater environments with varying impact of perfluoroalkyl substances (PFAS)

Given the pervasive detection of perfluoroalkyl substances (PFAS) in several environmental matrices and their known toxicological effects, it is imperative to investigate their impact on the physiological responses of freshwater organisms. This research is crucial for developing effective strategies to protect aquatic ecosystems by directly addressing how PFAS influences aquatic species' health and survival. In this study, we conducted a biomonitoring analysis to evaluate the effects of naturally occurring PFAS, specifically perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), on the physiology of common chub (Squalius cephalus), a freshwater fish native to the Veneto region. We measured oxidative damage in the kidney and skeletal muscle, with results showing that low PFAS contamination is sufficient to increase protein oxidation in both tissues. Conversely, even high PFAS levels did not induce lipid peroxidation in either tissue. We also examined the expression of peroxiredoxin isoform 4 (prdx4) in the kidney, finding its down-regulation with increasing PFAS pollution, which demonstrates the minor function of Prdx4 against oxidative stress. Instead, its down-regulation plays an important role in increasing lipid accumulation in the cell, creating a hydrophobic environment that limits PFAS bioaccumulation and their capacity to bind proteins, thus preserving them from further damage.

Advances in kidney disease: pathogenesis and therapeutic targets

Chronic kidney disease (CKD) is a global public health issue characterized by progressive loss of kidney function, of which end-stage kidney disease (ESKD) is the last stage. The global increase in the prevalence of CKD is linked to the increasing prevalence of traditional risk factors, including obesity, hypertension, and diabetes mellitus, as well as metabolic factors, particularly insulin resistance, dyslipidemia, and hyperuricemia. Mortality and comorbidities, such as cardiovascular complications, rise steadily as kidney function deteriorates. Patients who progress to ESKD require long-term kidney replacement therapy, such as transplantation or hemodialysis/peritoneal dialysis. It is currently understood that a crucial aspect of CKD involves persistent, low-grade inflammation. In addition, increased oxidative and metabolic stress, endothelial dysfunction, vascular calcification from poor calcium and phosphate metabolism, and difficulties with coagulation are some of the complex molecular pathways underlying CKD-related and ESKD-related issues. Novel mechanisms, such as microbiome dysbiosis and apolipoprotein L1 gene mutation, have improved our understanding of kidney disease mechanisms. High kidney disease risk of Africa has been linked to APOL1 high-risk alleles. The 3-fold increased risk of ESKD in African Americans compared to European Americans is currently mainly attributed to variants in the APOL1 gene in the chromosome 22q12 locus. Additionally, the role of new therapies such as SGLT2 inhibitors, mineralocorticoid receptor antagonists, and APOL1 channel function inhibitors offers new therapeutic targets in slowing down the progression of chronic kidney disease. This review describes recent molecular mechanisms underlying CKD and emerging therapeutic targets.

Effect of Per and Poly-Fluoroalkyl Substances on Pregnancy and Child Development

BACKGROUND

Childhood obesity is significantly influenced by maternal exposure to Per and Poly-Fluoroalkyl Substances (PFAS) during pregnancy. PFAS exposure occurs through the Peroxisome Proliferator-Activated Receptor (PPAR-γ) receptor, leading to increased fat deposition and profound health effects in child growth and development. Despite ongoing investigations, the relationship between maternal serum PFAS concentration and child obesity requires further exploration.

OBJECTIVE

This study aimed to review the possible effects of Per and poly-fluoroalkyl substances exposure and their mechanism in overweight/obese children from pregnant ladies.

METHODS

A detailed literature survey was conducted using online databases, including Science Direct, Google Scholar, Scopus, Cochrane, and PubMed. The study focused on the diverse effects of PFAS on maternal and child health, with particular emphasis on neurological complications.

RESULTS

Child growth development depends upon breastfeeding and placenta health, which is disrupted by PFAS exposure, ultimately destroying the body mass index of the child. Neurotoxicity testing utilized the SH-SY5Y human-derived cell line as an in vitro model, revealing PFAS-induced increases in adipocyte number, reduced cell size, altered lipid conglomeration, increased adiposity, and changes in liver function. in vivo studies in mice and human cell lines indicated PPAR-γ and ER-α activation, leading to adiposity and weight gain through Estrogen signaling and Lipid metabolism. PFAS concentrations positively correlated in maternal sera, analyzed by liquid chromatography/quadrupole mass spectrometry.

CONCLUSION

PFAS, with a long half-life of 3.5-8.5 years, is commonly found in the serum of pregnant women, crossing the placenta barrier. This exposure disrupts placental homeostasis, negatively impacting mechanisms of action and potentially leading to deterioration in pregnancy and child health. Further research is needed to comprehensively understand the complex interplay between PFAS exposure and its implications for maternal and child well-being.

Considerations for Measurements of Aggregate PFAS Exposure in Precision Environmental Health

Per- and polyfluoroalkyl substances (PFAS) have become a major focus of research due to their widespread environmental presence and adverse health effects associated with human exposure. PFAS include legacy and emerging structures and are characterized by a range of functional groups and carbon-fluorine chains that vary in length (from fewer than 3 carbons to more than 7 carbons). Research has linked PFAS exposure to an array of health concerns, ranging from developmental and reproductive disorders to immune system impairments and an increased risk of certain cancers. In this new era of personalized health, measuring markers of PFAS exposure in human biospecimens is an important part of environmental public health surveillance. PFAS are typically measured in human blood and tissues using targeted approaches, which quantify individual PFAS structures using specific instrumentation. The diversity and complexity of PFAS, the limitations of the targeted approaches due to the sheer number of structures, and the absence of publicly available analytical standards pose significant challenges for measurement methodologies. This perspective aims to describe aggregate PFAS exposure measurements and their potential for use in precision medicine applications including a discussion of the limitations and potential benefits of these aggregate measurements. As public health organizations, healthcare professionals, and the public look for guidance regarding the safe use of and exposure to PFAS, in a pragmatic cost-effective manner, the dynamic field of measurement science is poised to respond with innovative technological solutions to an important public health need.

Neurotoxicity of per- and polyfluoroalkyl substances: Evidence and future directions

Per- and polyfluoroalkyl substances (PFAS) are synthetic chemicals widely used in various products, including food packaging, textiles, and firefighting foam, owing to their unique properties such as amphiphilicity and strong CF bonds. Despite their widespread use, concerns have arisen due to their resistance to degradation and propensity for bioaccumulation in both environmental and human systems. Emerging evidence suggests a potential link between PFAS exposure and neurotoxic effects, spanning cognitive deficits, neurodevelopmental disorders, and neurodegenerative diseases. This review comprehensively synthesizes current knowledge on PFAS neurotoxicity, drawing insights from epidemiological studies, animal experiments, and mechanistic investigations. PFAS, known for their lipophilic nature, tend to accumulate in lipid-rich tissues, including the brain, breaching biological barriers such as the blood-brain barrier (BBB). The accumulation of PFAS within the central nervous system (CNS) has been implicated in a spectrum of neurological maladies. Neurotoxicity induced by PFAS manifests through a multitude of direct and indirect mechanisms. A growing body of research associated PFAS exposure with BBB disruption, calcium dysregulation, neurotransmitter alterations, neuroinflammation, oxidative stress, and mitochondrial dysfunction, all contributing to neuronal impairment. Despite notable strides in research, significant lacunae persist, necessitating further exploration to elucidate the full spectrum of PFAS-mediated neurotoxicity. Prospective research endeavors should prioritize developing biomarkers, delineating sensitive exposure windows, and exploring mitigation strategies aimed at safeguarding neurological integrity within populations vulnerable to PFAS exposure.

Tissue-specific distribution and fatty acid content of PFAS in the northern Bohai Sea fish: Risk-benefit assessment of legacy PFAS and emerging alternatives

This study aimed to examine the distribution of poly- and perfluoroalkyl substances (PFAS) in 15 marine fish species from the northern Bohai Sea, investigate their sources of contamination, and evaluate the benefits-risks associated with the concurrent consumption of fish fatty acids and PFAS. The ∑PFAS concentrations in fish ranged from 9.38 to 262.92 ng·g-1 (dry weight). The highest PFAS levels were found in the viscera and gills, while the lowest levels were found in the muscles. Industrial effluents and sewage treatment plant discharges were the primary sources of PFAS contamination. The individual PFAS concentrations in fish were insignificantly correlated with their trophic levels (p > 0.05). However, the concentrations of hexafluoropropylene oxide dimer acid (HFPO-DA) or long-chain PFAS (C > 8) significantly increased with fish size (e.g., total length, weight) and lipid content (p < 0.001). The benefit-risk analysis suggests that HPFO-DA poses a higher health risk than perfluorooctanoic acid (PFOA) in fish (p < 0.05). Long-term consumption of contaminated fish may significantly increase human serum PFOA concentration and kidney cancer risk (p < 0.05). Daily consumption of 5 g (wet weight) muscle from Ditrema temmincki and Konosirus punctatus is recommended to meet the requirements for fatty acid supplementation without posing health risks.

Per- and poly-fluoroalkyl substances (PFAS) accelerate biological aging mediated by increased C-reactive protein

Unhealthy biological aging is related to higher incidence of varied age-related diseases, even higher all-cause mortality. Previous small sample size study suggested that Per- and poly-fluoroalkyl substances (PFAS) was associated with biological aging, but the evidence of exposure-response relationships, potential effect modifiers, and potential mediators were not investigated. Therefore, we conducted a cross-sectional analysis of national study including 14, 865 adults in the US from 8 survey cycles of NHANES from 2003 to 2018, to investigate the associations of PFAS compounds in body serum, including perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), perfluorononanoic acid (PFNA), and perfluorohexane sulfonic acid (PFHxS), with biological aging. Generalized linear models showed that higher human exposure to PFAS was associated with accelerated biological aging. Importantly, human exposure to PFOA, PFOS, PFNA, and PFHxS with detected level (above 0.10 ng/mL) was associated with an average of 3.3 year (95 %CI: 2.7, 3.9, P < 0.001), 14.9 year (95 %CI: 7.2, 22.7, P < 0.001), 10.9 years (95 %CI: 3.9, 17.7, P < 0.001), and 8.8 years (95 %CI: 4.8, 12.9, P < 0.001) of biological aging acceleration. Cubic spline models indicated exposure-response relationships where there was no safe threshold of PFAS level regarding harms to human healthy aging. The weighted sum regression model found the significant associations of PFAS compound mixture with biological aging acceleration, and PFOA was the dominant contributor among 4 PFAS compounds. Mediation analysis suggested that C-reactive protein, one of the inflammation biomarkers, might play as mediator in PFAS-induced accelerated biological aging, but not Triglyceride-glucose index. In summary, our study suggests that the effects of PFAS on biological aging acceleration should be of concern and more action plans to address their negative impact on human health should be launched.

The Effects of Perfluorooctanesulfonic acid (PFOS) on Human Umbilical Vein Endothelial Cells (HUVECs) Proliferation and Gene Expression and its Implications on Fetal Development

Polyfluoro-alkyl substances (PFAS) are widely distributed environmental contaminants linked to human toxicity and developmental delays, especially low birthweight (LBW). In this study, Human Umbilical Vein Endothelial Cells (HUVECs) were exposed to the PFAS perfluorooctanesulfonic acid (PFOS). After 48-hours, their proliferation, and differential gene expression were assessed. A small, yet significant, reduction in proliferation was seen at 50 μg/mL and 75 μg/mL. RNA sequencing showed that estrogen response and notch signaling pathways were significantly altered. This study increases our understanding of how PFAS may interfere with endothelial cell (HUVECs) functions which may have larger effects on fetal growth, development, and birthweight.

Transplacental transfer of perfluorinated and poly-fluorinated substances in maternal-cord serum and association with birth weight: A birth cohort study, China

Although the effects of traditional perfluorinated and polyfluorinated substances (PFASs) exposure have been extensively explored, research on novel PFASs remains limited, and there is a lack of data regarding their placental transfer and fetal impact. Herein, we aimed to examine maternal and fetal PFASs exposure levels, placental transfer efficiency (TTE), and the consequences of prenatal exposure on birth weight. The study included 214 mother-child pairs recruited in Wuxi birth cohort from 2019 to 2021. Twenty-three PFASs were quantified in maternal serum during the second trimester and umbilical serum during delivery. Median concentrations of ∑23PFASs in maternal and cord sera were 9.34 and 6.88 ng/mL, respectively. The novel alternatives exhibited elevated levels of maternal and fetal exposure, such as perfluorovaleric acid (PFPeA, 2.00 ng/mL and 1.66 ng/mL, respectively) and perfluorohexane sulfonate (PFHxS, 1.77 and 1.14 ng/mL, respectively). With increasing carbon chain length, the TTE of perfluorocarbonic acid (PFCAs) displayed a pattern of initially decreasing before subsequently increasing, with novel alternatives exhibiting a relatively high TTE. Multiple linear regression showed that exposure to perfluorobutane sulfonate (PFBS) and PFPeA in cord serum positively correlated with the birth weight of female infants (β = 231.04 g, 95% confidence interval [CI]: 21.73-440.36; β = 121.26 g, 95% CI: 29.51-213.00). No nonlinear relationship was observed between cord serum PFASs and birth weight. The weighted quantile sum (WQS) regression analysis has reaffirmed that PFPeA and PFBS were predominant contributors to the positive correlation observed between the mixture of PFASs and birth weight. Our findings suggest that novel PFASs may exhibit a heightened susceptibility for transplacental transfer and that exposure to PFBS and PFPeA during pregnancy could be linked to increased birth weight.

Association between PFAS exposure and thyroid health: A systematic review and meta-analysis for adolescents, pregnant women, adults and toxicological evidence

A burgeoning body of epidemiological and toxicological evidence suggests that thyroid health may be significantly impacted by exposure to both long- and short-chain perfluoroalkyl substances (PFAS) compounds. We conducted a meta-analysis to examine the association between 16 PFAS compounds and five thyroid hormones (TSH, TT3, TT4, FT3, and FT4) in the serum of a pregnant women, adolescents, and adults. The dose-response relationship between some PFAS and thyroid hormones in different population subpopulation was found and the model was fitted. We also amalgamated data from 18 animal experiments with previously published in vitro studies to elucidate the toxicological mechanisms underlying the impact of PFAS on the thyroid gland. The results of the study showed that (a) both conventional and emerging PFAS compounds were identified in human samples and exhibited associations with thyroid health outcomes; (b) in animal studies, PFAS have been found to impact thyroid gland health through two primary mechanisms: by influencing the hypothalamic-pituitary-thyroid axis and by binding to thyroid receptors. This study provides a systematic description of the health effects and risk assessment associated with PFAS exposure on the thyroid gland. Furthermore, dose-response relationships were established through the Hill model in python.

Associations between co-exposure to per- and polyfluoroalkyl substances and metabolic diseases: The mediating roles of inflammation and oxidative stress

BACKGROUND

Per- and polyfluoroalkyl substances (PFAS) pose potential risks to human health. In real-world settings, humans are exposed to various PFAS through numerous pathways.

OBJECTIVES

This study evaluated the associations between co-exposure to PFAS and obesity and its comorbidities, along with the mediating roles of inflammation and oxidative stress.

METHODS

We analyzed 11,090 participants from National Health and Nutrition Examination Survey (NHANES), 2003-2018. Linear regression, logistic regression, and generalized additive models were used to assess the individual effects of PFAS exposure on obesity and its comorbidities. The environmental risk score (ERS) was calculated using the adaptive elastic-net model to assess the co-exposure effects. Linear and logistic regression models explored the associations between ERS and obesity and its comorbidities. Mediation analyses explored the roles of inflammatory (neutrophils, lymphocytes, and alkaline phosphatase) and oxidative stress (gamma-glutamyl transferase, total bilirubin, and uric acid) markers in the associations between ERS and obesity and its comorbidities.

RESULTS

For each unit increase in ERS, the odds of obesity and type 2 diabetes mellitus (T2DM) increased 3.60-fold (95 % CI: 2.03, 6.38) and 1.91-fold (95 % CI: 1.28, 2.86), respectively. For each unit increase in ERS, BMI increased by 2.36 (95 % CI: 1.24, 3.48) kg/m2, waist circumference increased by 6.47 (95 % CI: 3.56, 9.37) cm, and waist-to-height ratio increased by 0.04 (95 % CI: 0.02, 0.06). Lymphocytes, alkaline phosphatase, and total bilirubin were significantly associated with both ERS and obesity, with mediation proportions of 4.17 %, 3.62 %, and 7.37 %, respectively. Lymphocytes, alkaline phosphatase, total bilirubin, and uric acid were significantly associated with both ERS and T2DM, with the mediation proportions of 8.90 %, 8.74 %, 29.73 %, and 38.19 %, respectively.

CONCLUSIONS

Co-exposure to PFAS was associated with obesity and T2DM, and these associations may be mediated by inflammation and oxidative stress. Further mechanistic and prospective studies are required to verify these associations.

Comparative Proteomics Highlights that GenX Exposure Leads to Metabolic Defects and Inflammation in Astrocytes

Exposure to PFAS such as GenX (HFPO dimer acid) has become increasingly common due to the replacement of older generation PFAS in manufacturing processes. While neurodegenerative and developmental effects of legacy PFAS exposure have been studied in depth, there is a limited understanding specific to the effects of GenX exposure. To investigate the effects of GenX exposure, we exposed Drosophila melanogaster to GenX and assessed the motor behavior and performed quantitative proteomics of fly brains to identify molecular changes in the brain. Additionally, metabolic network-based analysis using the iDrosophila1 model unveiled a potential link between GenX exposure and neurodegeneration. Since legacy PFAS exposure has been linked to Parkinson's disease (PD), we compared the proteome data sets between GenX-exposed flies and a fly model of PD expressing human α-synuclein. Considering the proteomic data- and network-based analyses that revealed GenX may be regulating GABA-associated pathways and the immune system, we next explored the effects of GenX on astrocytes, as astrocytes in the brain can regulate GABA. An array of assays demonstrated GenX exposure may lead to mitochondrial dysfunction and neuroinflammatory response in astrocytes, possibly linking non-cell autonomous neurodegeneration to the motor deficits associated with GenX exposure.

Forever chemicals don't make hero mutant ninja turtles: Elevated PFAS levels linked to unusual scute development in newly emerged freshwater turtle hatchlings (Emydura macquarii macquarii) and a reduction in turtle populations

Per- and polyfluoroalkyl substances (PFAS) are persistent environmental contaminants known to pose significant risks to human and wildlife health. Freshwater turtles (Emydura macquarii macquarii), as long-lived species inhabiting aquatic ecosystems, are particularly vulnerable to PFAS bioaccumulation. This study investigated the multifaceted impact of PFAS contamination on these turtles, focusing on metabolic disruptions, reproductive success, hatchling health, and population impacts. Comprehensive analyses, including proteomics, lipidomics, metabolomics, and histopathology, were conducted on turtles from PFAS-impacted, control, and reference sites. The findings reveal significant metabolic disruptions in PFAS-exposed turtles, with alterations in amino acid and lipid metabolism, energy production, and oxidative stress responses. Proteomic analysis identified several health biomarkers indicative of early disease progression. Despite high levels of PFAS in tissues and organs, no gross or histopathological phenotypical abnormalities were directly linked to PFAS exposure. Gravid females from contaminated sites exhibited altered egg composition, particularly in magnesium to calcium ratios, potentially affecting eggshell strength. Biochemical profiles of egg albumin and yolk indicated significant differences in metabolites and lipids between contaminated and reference sites, suggesting potential impacts on embryo development. Hatchling deformities were notably higher and with increased frequency in terms of the types of deformities at the PFAS-impacted sites, with common defects including abnormal intergular scale shapes and marginal scale counts. Furthermore, the demographic profile of the turtle population showed a lack of juvenile turtles at contaminated sites, indicating reduced recruitment and potential long-term population declines. This indicates a field-based demonstration of an Adverse Outcome Pathway, from elevated levels of PFAS in the turtles, to biochemical perturbations within the animals, and finally population effects. These findings underscore the urgent need for regulatory measures to address PFAS contamination and its detrimental effects on wildlife.

A combinational threat of micro- and nano-plastics (MNPs) as potential emerging vectors for per- and polyfluoroalkyl substances (PFAS) to human health

Micro- and nano-plastics (MNPs) and per- and polyfluoroalkyl substances (PFAS) are prevalent in ecosystems due to their exceptional properties and widespread use, profoundly affecting both human health and ecosystem. Upon entering the environment, MNPs and PFAS undergo various transformations, such as weathering, transport, and accumulation, potentially altering their characteristics and structural dynamics. Their interactions, governed by factors like hydrogen bonding, hydrophobic interactions, Van der Waals forces, electrostatic attractions, and environmental conditions, can amplify or mitigate their toxicity toward human health within ecological conditions. Several studies demonstrate the in vivo effects of PFAS and MNPs, encompassing growth and reproductive impairments, oxidative stress, neurotoxicity, apoptosis, DNA damage, genotoxicity, immunological responses, behavioral changes, modifications in gut microbiota, and histopathological alterations. Moreover, in vitro investigations highlight impacts on cellular uptake, affecting survival, proliferation, membrane integrity, reactive oxygen species (ROS) generation, and antioxidant responses. This review combines knowledge on the co-existence and adsorption of PFAS and MNPs in the environment, defining their combined in vivo and in vitro impacts. It provides evidence of potential human health implications. While significant research originates from China, Europe, and the USA, studies from other regions are limited. Only freshwater and marine organisms and their impacts are extensively studied in comparison to terrestrial organisms and humans. Nonetheless, detailed investigations are lacking regarding their fate, combined environmental exposure, mode of action, and implications in human health studies. Ongoing research is imperative to comprehensively understand environmental exposures and interaction mechanisms, addressing the need to elucidate these aspects thoroughly.

Perfluorooctane sulfonate (PFOS) and benzo[a]pyrene (BaP) synergistically induce neurotoxicity in C6 rat glioma cells via the activation of neurotransmitter and Cyp1a1-mediated steroid hormone synthesis pathways

Humans are often exposed to complex mixtures of multiple pollutants rather than a single pollutant. However, the combined toxic effects and the molecular mechanism of PFOS and BaP remain poorly understood. In this study, two typical environmental pollutants, perfluorooctane sulfonate acid (PFOS) and benzo [a]pyrene (BaP), were selected to investigate their combined neurotoxic effects on rat C6 glioma cells at environmentally relevant concentrations. The results showed that coexposure to low-dose PFOS and BaP induced greater toxicity (synergistic effect) than did single exposure. PFOS-BaP coexposure had stronger toxic effects on inducing oxidative stress and promoting early apoptosis. Targeted metabolomics confirmed that increased levels of the neurotransmitters 5-hydroxytryptophan, dopamine, tryptophan and serotonin disturb the phenylalanine, tyrosine and tryptophan biosynthesis pathways. Mechanistically, exposure to a low-dose PFOS-BaP binary mixture induces steroid hormone synthesis disorder through the activation of Cyp1a1 and Hsd17b8 (steroid hormone synthesis genes) and Dhcr24 and Dhcr7 (cholesterol synthesis genes). These findings are useful for comprehensively and systematically elucidating the biological safety of PFOS-BaP and its potential threats to human health.

Effect of physicochemical parameters on the occurrence of per- and polyfluoroalkyl substances (PFAS) in aquatic environment

Perfluoroalkyl substances (PFAS) and their distribution in aquatic environments have been studied extensively, but more information is needed to link these occurrences to their physicochemical characteristics. Understanding how these parameters influence PFAS can help predict their fate, mobility, and occurrences in water. This study reviewed the influence of physicochemical parameters on the occurrences of PFAS in aquatic environment using the relevant keywords to retrieve articles from databases spanning mostly between 2017 and 2024. The result suggests that high pH, turbidity, and dissolved oxygen, give high concentration of PFAS, while high electrical conductivity, temperature and salinity give low PFAS concentration in the water. Therefore, monitoring and safeguarding the aquatic bodies for human and environmental safety is imperative. Future studies should include the effects of the physicochemical properties on PFAS occurrences in the natural environment and focus on an organism's distinctive characteristics to comprehend the bioaccumulation and biomagnification of PFAS in them and environmental matrices.

Unveiling the Molecular Effects of Replacement and Legacy PFASs: Transcriptomic Analysis of Zebrafish Embryos Reveals Surprising Similarities and Potencies

The prevalence of per- and poly fluoroalkyl substances (PFASs) in the environment has prompted restrictions on legacy PFASs due to their recognized toxic effects. Consequently, alternative "replacement" PFASs have been introduced and are prevalent in environmental matrices. Few studies have investigated the molecular effects of both legacy and replacement PFASs under short-term exposures. This study aimed to address this by utilizing transcriptomic sequencing to compare the molecular impacts of exposure to concentrations 0.001-5 mg/L of the legacy PFOS and two of its replacements, PFECHS and FBSA. Using zebrafish embryos, the research assessed apical effects (mortality, morphology, and growth), identified differentially expressed genes (DEGs) and enriched pathways, and determined transcriptomic points of departure (tPoDs) for each compound. Results indicated that PFOS exhibited the highest relative potency, followed by PFECHS and then FBSA. While similarities were observed among the ranked DEGs across all compounds, over-representation analysis revealed slight differences. Notably, PFOS demonstrated the lowest tPoD identified to date. These findings raise concerns regarding the safety of emerging replacement PFASs and challenge assumptions about PFAS toxicity solely resulting from their accumulative potential. As replacement PFASs proliferate in the environment, this study underscores the need for heightened scrutiny of their effects and questions current regulatory thresholds.

Evaluation of per- and polyfluoroalkyl substances (PFAS) toxic effects on the acute inflammatory response in the medicinal leech Hirudoverbana

Per- and polyfluoroalkyl (PFAS) substances are a large group of chemicals with elevated water and oil-resistance properties, widely implicated in various applicative fields. Due to the extensive use and high resistance to degradative factors, these compounds pose a significant risk of environmental spreading, bioaccumulating also in living organisms. In this context, despite many researches have been performed to demonstrate "legacy" PFAS harmfulness, only few data are still available about all the emerging fluorinated molecules, industrially introduced to replace the previous ones. For this reason, we proposed the medicinal leech Hirudo verbana as consolidated invertebrate model to assess the effects of four different PFAS (HFPO-DA, PFMoBa, PFOA and PFMOPrA) following freshwater dispersion. Morphological, immunohistochemical and molecular analyses demonstrate that, despite all the compounds basically induce an acute inflammatory and oxidative stress response, a different cellular and molecular response has been observed. Whereas for PFOA and PFMOPrA an increase in the tested concentration leads to a corresponding rise in the immune response, HFPO-DA and PFMoBa trigger an entirely opposite effect. Indeed, the significant recruitment of both granulocytes and macrophage like cells, typically involved in the removal of non-self, is inhibited with increasing concentrations of these compounds. The data collected revealed a different sensitivity of the leech immune system following PFAS exposure, requiring to deepen the current knowledge on the potential toxicity of these compounds.

Comparative toxicity assessment of alternative versus legacy PFAS: Implications for two primary trophic levels in freshwater ecosystems

Perfluoroalkyl substances (PFAS) are common environmental pollutants, but their toxicity framework remains elusive. This research focused on ten PFAS, evaluating their impacts on two ecotoxicologically relevant model organisms from distinct trophic levels: the crustacean Daphnia magna and the unicellular green alga Raphidocelis subcapitata. The results showed a greater sensitivity of R. subcapitata compared to D. magna. However, a 10-day follow-up to the 48 h immobilisation test in D. magna showed delayed mortality, underlining the limitations of relying on EC50 s from standard acute toxicity tests. Among the compounds scrutinized, Perfluorodecanoic acid (PFDA) was the most toxic to R. subcapitata, succeeded by Perfluorooctane sulfonate (PFOS), Perfluorobutanoic acid (PFBA), and Perfluorononanoic acid (PFNA), with the latter being the only one to show an algicidal effect. In the same species, assessment of binary mixtures of the compounds that demonstrated high toxicity in the single evaluation revealed either additive or antagonistic interactions. Remarkably, with an EC50 of 31 mg L-1, the short-chain compound PFBA, tested individually, exhibited toxicity levels akin to the notorious long-chain PFOS, and its harm to freshwater ecosystems cannot be ruled out. Despite mounting toxicological evidence and escalating environmental concentrations, PFBA has received little scientific attention and regulatory stewardship. It is strongly advisable that regulators re-evaluate its use to mitigate potential risks to the environmental and human health.

Early Pregnancy Plasma Per- and Polyfluoroalkyl Substances (PFAS) and Maternal Midlife Adiposity

CONTEXT

Evidence suggests that exposure to per- and polyfluoroalkyl substances (PFAS) increases the risk of developing cardiometabolic disease risk factors. Limited research has evaluated associations between PFAS, assessed during pregnancy, a sensitive window for maternal endocrine effects, and long-term maternal adiposity.

OBJECTIVE

Estimate associations of early pregnancy measures of individual PFAS, and PFAS mixtures, with maternal adiposity in midlife.

METHODS

We studied 547 Project Viva participants with measures of early pregnancy (mean gestation 10.0 weeks; mean age 32.5 years) plasma concentrations of 6 PFAS and midlife adiposity outcomes (mean follow-up 17.7 years; mean age 50.7 years), including weight, waist circumference (WC), trunk fat mass (TFM), and total body fat mass (TBFM). We used linear regression and Bayesian Kernel Machine Regression (BKMR).

RESULTS

Linear regression estimated higher midlife weight per doubling of perfluorooctane sulfonate (PFOS) (3.8 kg [95% CI: 1.6, 5.9]) and 2-(N-ethyl-perfluorooctane sulfonamido) acetate (2.3 kg [95% CI: 0.9, 3.7]). BKMR analyses of single PFAS plasma concentrations (comparing the 25th percentile concentration to the 75th percentile) showed a positive association between PFOS and midlife adiposity (weight: 7.7 kg [95% CI: 4.0, 11.5]; TFM: 1.2 kg [95% CI: 0.0, 2.3]; TBFM: 3.0 kg [95% CI: 0.8, 5.2]), but inverse associations with perfluorononanoate (weight: -6.0 kg [95% CI: -8.5, -3.5]; WC: -1.8 cm [95% CI: -3.2, -0.3]; TFM: -0.8 kg [95% CI: -1.5, -0.1]; TBFM: -1.4 kg [95% CI: -2.7, -0.3]) and perfluorohexane sulfonate (TFM: -0.8 kg [95% CI: -1.5, -0.1]; TBFM: -1.4 kg [95% CI: -2.6, -0.2]). No associations were observed with the overall PFAS mixture.

CONCLUSION

Select PFAS, assessed in pregnancy, may differentially affect maternal midlife adiposity, influencing later-life maternal cardiometabolic health.

Assessment of per- and poly-fluoroalkyl substances and physiological biomarkers in aquarium-based bottlenose dolphins and killer whales

Environmental concerns about per- and polyfluoroalkyl substances (PFAS) are considerably increasing due to their extensive use in commercial and consumer products. PFAS bioaccumulate and biomagnify throughout the food chain, and their toxicity and potential adverse health effects can potentially represent a threat to living organisms. In this study, we described PFAS profiles in the serum of two species of zoo-based bottlenose dolphins (Tursiops truncatus, n = 14 individuals) and killer whales (Orcinus orca, n = 14 individuals) from three locations (California, Florida, and Texas, USA), from 1994 to 2020. Potential physiological effects of PFAS were also explored by measuring different biomarkers (cortisol, corticosterone, aldosterone, TBARS, and hydrogen peroxide) while accounting for individual age, sex, and reproductive stage. All PFAS were detected in at least one of the individuals, considering both species. ΣPFAS reached 496 ng mL-1 in bottlenose dolphins and 230 ng mL-1 in killer whales. In both species, the PFAS with higher mean concentrations were PFOS (108.0-183.0 ng ml-1) and PFNA (14.40-85.50 ng ml-1), which are long-chain compounds. Newborn individuals of both species were also exposed to PFAS, indicating transference via placenta and lactation. Linear mixed model analyses indicated significant correlations between aldosterone, month, year, location, and status; and between hydrogen peroxide, month, year, age, status, ΣPFAS, and Σ short-chain PFAS in killer whales suggesting seasonal variations related to the animal's physiological state (e.g., reproductive cycles, stress responses, weaning events) and increased reactive oxygen species formation due to PFAS exposure. Given our results, other contaminant classes should be investigated in cetaceans as they might have additive and synergistic detrimental effects on these individuals. This study lays the foundation to guide future researchers and highlights the importance of such assessments for animal welfare, and species conservation. Our results may inform management decisions regarding regulations of contaminant thresholds in delphinids.

Exposure to per- and polyfluoroalkyl substances and age-related macular degeneration in U.S. middle-aged and older adults

Despite various health effects of per- and polyfluoroalkyl substances (PFAS) exposure, the association between PFAS exposure and age-related macular degeneration (AMD) has not been investigated. We aimed to assess associations of PFAS exposure with AMD, using data from 1722 U.S. adults aged 40 years or more participating in the National Health and Nutrition Examination Survey 2005-2008 with complete data on PFAS measurement, AMD diagnosis, and covariates. Serum concentrations of PFAS, including perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorohexane sulfonic acid (PFHxS), and perfluorooctane sulfonic acid (PFOS), were measured. An overall PFAS burden score was calculated using item response theory scoring. Individual PFAS concentration and overall PFAS burden score were categorized into low (reference), medium, and high groups. Diagnosis of AMD was based on retinal image examination. Any AMD was defined as the presence of early or late AMD. Survey-weighted logistic regression adjusted for potential confounders was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for presence of AMD according to PFAS exposure. Overall, 132 (6.5%) individuals were diagnosed as any AMD, including 115 (5.7%) individuals with early AMD. A significant dose-response association was observed between serum PFOS concentration and any AMD (p-trend = 0.03), with a significant OR of 1.99 (95% CI: 1.05, 3.79) for the high group compared to the reference. Overall PFAS burden showed a non-monotonic association with any AMD, with a significant OR of 2.18 (95% CI: 1.18, 4.04) for the medium. Inverted U-shaped associations were observed by restricted cubic spline analyses. Also, early AMD showed similar patterns in PFOS and overall PFAS burden and additionally an inverted U-shape association in PFNA. Our findings suggest that exposure to PFAS estimated by serum PFOS and PFNA as well as overall PFAS burden might be a risk factor for AMD in middle-aged and older population.

Emerging eco-friendly technologies for remediation of Per- and poly-fluoroalkyl substances (PFAS) in water and wastewater: A pathway to environmental sustainability

Per- and polyfluoroalkyl substances (PFAS) are rampant, toxic contaminants from anthropogenic sources, called forever chemicals for their recalcitrance. Although banned in several parts of the world for public health implications, including liver, kidney, and testicular diseases, PFAS are abundant in water sources due to easy dispersion. With chemical properties resulting from strong hydrophobic bonds, they defile many physicochemical removal methods. Though adsorption processes such as granular activated carbon (GAC) are widely used, they are marred by several limitations, including cost and secondary contamination. Thus, eco-friendly methods involving a synergy of the removal principles have been preferred for ease of use, cost-effectiveness, and near-zero effect on the environment. We present novel eco-friendly methods as the solution to PFAS remediation towards environmental sustainability. Current eco-friendly methods of PFAS removal from water sources, including electrocoagulation, membrane/filtration, adsorption, and phytoremediation methods, were highlighted, although with limitations. Novel eco-friendly methods such as microbial fuel cells, photoelectrical cells, and plasma treatment offer solutions to PFAS remediation and are quite efficient in terms of cost, result, and environmental sustainability. Overall, the successful integration of eco-friendly techniques in a seamless manner ensures the desired result. We also present a balanced position on the ecosystem impact of these ecofriendly methods, noting the successes towards environmental sustainability while exposing the gaps for further research.

Cortisol levels reveal species-specific stress condition in fish from PFAS polluted rivers

In the context of increasing environmental contamination, our study employed fish as bioindicators, focusing on non-invasive cortisol measurements in scales and fins in response to severe PFAS pollution in the Veneto area of Italy. Our preliminary findings showed species-specific stress responses, as observed in Squalius cephalus and Padogobius bonelli, suggesting the need for broader biomonitoring to capture the complex impact of environmental stressors on aquatic organisms. Moreover, due to the unusual characteristics of the rivers selected for the biomonitoring activity, a possible link between PFAS exposure and cortisol levels in S. cephalus demonstrates the method's potential.

Drinking water quality impacts oocyte viability and embryo development

Normal reproductive function and fertility is considered a "sixth vital sign" because disruptions to this sensitive physiological system can forewarn other health issues, including exposure to environmental toxicants. We found that female mice exhibited profound loss of embryos during pre-implantation and fetal development coincident with a change to the source of their drinking water. When female mice were provided with tap water from the building in which they were housed (Water 2), instead of tap water from a neighboring building which was their previous supply (Water 1), ovulated oocytes were degenerated or had impaired meiotic maturation, and failed to form embryos. The harmful effects of Water 2 exposure were not reversible even following a recovery period; however, carbon-filtration of Water 2 removed the toxic contaminant. Water composition analysis to identify the responsible toxicant(s) found that trace elements were present at expected levels and phthalates were undetectable. Per- and Poly-fluoroalkyl Substances (PFAS), a family of persistent organic pollutants were detected at ∼4 ng/L. To investigate further, female mice were given drinking water categorized by level of PFAS contamination (0.6 ng/L, 2.8 ng/L, or 4.4 ng/L) for 9 weeks. Compared to mice consuming purified MilliQ water, mice consuming PFAS-contaminated water had decreased oocyte quality, impaired embryogenesis and reduced cell numbers in blastocysts. PFAS concentration in the drinking water was negatively correlated with oocyte viability. Importantly, the levels of PFAS detected in the tap water are within current "safe level" guidelines, and further research is needed to determine whether PFAS are responsible for the observed reproductive toxicity. However, this research demonstrating that water deemed suitable for human consumption has detrimental effects on mammalian embryo development has important implications for public health and water quality policies.

Prenatal Exposure of PFAS in Cohorts of Pregnant Women: Identifying the Critical Windows of Vulnerability and Health Implications

Cohorts of pregnant women in 2018 and 2020 were selected to explore prenatal exposure to perfluoroalkyl and polyfluoroalkyl substances (PFAS). Maternal serum during the whole pregnancy (first to third trimesters) and matched cord serum were collected for the analysis of 50 PFAS. Perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), and 6:2 fluorotelomer sulfonic acid (6:2 FTS) were the dominant PFAS in both the maternal and cord serum. The median ∑PFAS concentration was 14.18 ng/mL, and the ∑PFAS concentration was observed to decline from the first trimester to the third trimester. The transplacental transfer efficiencies (TTE) of 29 PFAS were comprehensively assessed, and a "U"-shaped trend in TTE values with increasing molecular chain length of perfluoroalkyl carboxylic acid (PFCA) was observed in this study. Moreover, the maternal concentrations of 9-chlorohexadecafluoro-3-oxanonane-1-sulfonic acid (6:2 Cl-PFESA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUdA), perfluorododecanoic acid (PFDoA), PFOS, and hexafluoropropylene oxide dimer acid (HFPO-DA) in the 2020 cohort were significantly lower than those in the 2018 cohort, declining by about 23.85-43.2% from 2018 to 2020 (p < 0.05). Higher proportions of emerging PFAS were observed in fetuses born in 2020. This birth cohort was collected during the COVID-19 epidemic period. The change in the PFAS exposure scene might be in response to the different exposure profiles of the 2018 and 2020 cohorts, which are attributed to the impact of COVID-19 on the social activities and environment of pregnant women. Finally, by application of a multiple informant model, the third trimester was identified as the critical window of vulnerability to PFAS exposure that affects birth weight and birth length.

Association Between Prenatal Exposure to Per- and Poly-Fluoroalkyl Substances From Electronic Waste Disassembly Areas and Steroid Hormones in Human Milk Samples

Per- and poly-fluoroalkyl substances (PFAS), which are long-lasting environmental contaminants that are released into the environment during the e-waste disassembly process, pose a threat to human health. Human milk is a complex and dynamic mixture of endogenous and exogenous substances, including steroid hormones and PFAS. Therefore, in this study, we aimed to investigate the association between PFAS and steroid hormones in human milk from women living close to an e-waste disassembly area. In 2021, we collected milk samples from 150 mothers within 4 weeks of delivery and analyzed them via liquid chromatography-tandem mass spectrometry to determine the levels of 21 perfluorinated compounds and five steroid hormones (estrone, estriol, testosterone, progesterone, and androstenedione [A-dione]). We also performed multiple linear regression analysis to clarify the association between maternal PFAS exposure and steroid hormone concentrations. Our results indicated that PFOA and PFOS were positively associated with estrone (β, 0.23; 95% CI, 0.08-0.39) and A-dione (β, 0.186; 95% CI, 0.016-0.357) concentrations in human milk, respectively. Further, the average estimated daily intake of PFOA and PFOS were 36.5 ng/kg bw/day (range, 0.52-291.7 ng/kg bw/day) and 5.21 ng/kg bw/day (range, 0.26-32.3 ng/kg bw/day), respectively. Of concern, the PFAS intake of breastfeeding infants in the study area was higher than the recommended threshold. These findings suggested that prenatal exposure to PFAS from the e-waste disassembly process can influence steroid hormones levels in human milk. Increased efforts to mitigate mother and infant exposure to environmental pollutants are also required.

Prenatal per- and polyfluoroalkyl substances (PFAS) and maternal oxidative stress: Evidence from the LIFECODES study

BACKGROUND

Per- and polyfluoroalkyl substances (PFAS) are synthetic chemicals linked to adverse pregnancy outcomes. Although their underlying biological mechanisms are not fully understood, evidence suggests PFAS may disrupt endocrine functions and contribute to oxidative stress (OS) and inflammation.

OBJECTIVE

We examined associations between early pregnancy PFAS exposure and OS biomarkers, exploring potential effect modifications by fetal sex and maternal race.

METHODS

We used data from 469 LIFECODES participants with measured plasma PFAS (median 10 weeks gestation) and repeated measures (median 10, 18, 26, and 35 weeks gestation) of urinary OS biomarkers [8-iso-prostaglandin-F2α (8-isoprostane) and 8-hydroxydeoxyguanosine (8-OHdG)]. Protein damage biomarkers (chlorotyrosine, dityrosine, and nitrotyrosine) were additionally measured in plasma from a subset (N = 167) during the third visit. Associations between each PFAS and OS biomarkers were examined using linear mixed-effects models and multivariable linear regressions, adjusting for potential confounders, including maternal age, race, education level, pre-pregnancy BMI, insurance status, and parity. Effect modifications were evaluated by including an interaction term between each PFAS and fetal sex or maternal race in the models.

RESULTS

We observed significant positive associations between PFOS and 8-isoprostane, with a 9.68% increase in 8-isoprostane levels (95% CI: 0.10%, 20.18%) per interquartile range increase in PFOS. In contrast, PFUA was negatively associated [9.32% (95% CI: -17.68%, -0.11%)], while there were suggestive positive associations for MPAH and PFOA with 8-isoprostane. The associations of several PFAS with 8-OHdG varied by fetal sex, showing generally positive trends in women who delivered females, but negative or null in those who delivered males. No significant effect modification by maternal race was observed.

CONCLUSIONS

This study provides evidence linking PFAS exposure to OS during pregnancy, with potential sex-specific effects of certain PFAS on 8-OHdG. Further research should explore additional OS/inflammatory biomarkers and assess the modifying effects of dietary and behavioral patterns across diverse populations.

Effects of developmental exposure to individual and combined PFAS on development and behavioral stress responses in larval zebrafish

Per- and polyfluoroalkyl substances (PFAS) are a class of synthetic chemicals known for their widespread use and persistence in the environment. Laboratory and epidemiological studies investigating these compounds have signaled their neurotoxic and endocrine-disrupting propensities, prompting further research into their effects on behavioral stress responses and their potential role as risk factors for stress-related disorders such as anxiety and depression. This study elucidates the ramifications of early developmental exposures to individual and combined PFAS on the development and behavioral stress responses of larval zebrafish (Danio rerio), an established model in toxicological research. Wild-type zebrafish embryos were enzymatically dechorionated and exposed to PFOS, PFOA, PFHxS, and PFHxA between 6 and 120 h post-fertilization (hpf). We targeted environmentally relevant concentrations stemming from the USEPA 2016 Hazard Advisory Limit (HAL, 0.07 μg/L) and folds higher (0.35, 0.7, 1.75, and 3.5 μg/L). Evaluations at 120 hpf encompassed mortality, overall development, developmental defects, and larval activity both at baseline stress levels and following exposure to acute stressors (acoustic and visual). Larval exposure to PFOA, PFOS, or PFHxS (0.07 μg/L or higher) elicited significant increases in mortality rates, which capped at 23.1%. Exposure to individual chemicals resulted in limited effects on overall development but increased the prevalence of developmental defects in the body axis, swim bladder, pigmentation, and eyes, as well as the prevalence of yolk sac and pericardial edemas. Larval activity at baseline stress levels and following exposure to acute stimuli was significantly altered. Combined exposure to all four chemicals intensified the breadth of developmental and behavioral alterations, suggesting possible additive or synergistic effects. Our findings shed light on the developmental and neurobehavioral disturbances associated with developmental exposure to PFAS at environmentally relevant concentrations, the added risks of combined exposures to these chemicals, and their possible role as environmental risk factors for stress-related disorders.

Persistent organic pollutants dysregulate energy homeostasis in human ovaries in vitro

Exposure to persistent organic pollutants (POPs), such as dichlorodiphenyltrichloroethane (DDT) and polychlorinated biphenyls (PCBs), has historically been linked to population collapses in wildlife. Despite international regulations, these legacy chemicals are still currently detected in women of reproductive age, and their levels correlate with reduced ovarian reserve, longer time-to-pregnancy, and higher risk of infertility. However, the specific modes of action underlying these associations remain unclear. Here, we examined the effects of five commonly occurring POPs - hexachlorobenzene (HCB), p,p'-dichlorodiphenyldichloroethylene (DDE), 2,3,3',4,4',5-hexachlorobiphenyl (PCB156), 2,2',3,4,4',5,5'-heptachlorobiphenyl (PCB180), perfluorooctane sulfonate (PFOS) - and their mixture on human ovaries in vitro. We exposed human ovarian cancer cell lines COV434, KGN, and PA1 as well as primary ovarian cells for 24 h, and ovarian tissue containing unilaminar follicles for 6 days. RNA-sequencing of samples exposed to concentrations covering epidemiologically relevant levels revealed significant gene expression changes related to central energy metabolism in the exposed cells, indicating glycolysis, oxidative phosphorylation, fatty acid metabolism, and reactive oxygen species as potential shared targets of POP exposures in ovarian cells. Alpha-enolase (ENO1), lactate dehydrogenase A (LDHA), cytochrome C oxidase subunit 4I1 (COX4I1), ATP synthase F1 subunit alpha (ATP5A), and glutathione peroxidase 4 (GPX4) were validated as targets through qPCR in additional cell culture experiments in KGN. In ovarian tissue cultures, we observed significant effects of exposure on follicle growth and atresia as well as protein expression. All POP exposures, except PCB180, decreased unilaminar follicle proportion and increased follicle atresia. Immunostaining confirmed altered expression of LDHA, ATP5A, and GPX4 in the exposed tissues. Moreover, POP exposures modified ATP production in KGN and tissue culture. In conclusion, our results demonstrate the disruption of cellular energy metabolism as a novel mode of action underlying POP-mediated interference of follicle growth in human ovaries.

Sub-acute exposure of male guppies (Poecilia reticulata) to environmentally relevant concentrations of PFOA and GenX induces significant changes in the testis transcriptome and reproductive traits

Poly- and perfluoroalkyl substances (PFAS) are frequently detected in the environment and are linked to adverse reproductive health outcomes in humans. Although legacy PFAS have been phased out due to their toxicity, alternative PFAS are increasingly used despite the fact that information on their toxic effects on reproductive traits is particularly scarce. Here, we exposed male guppies (Poecilia reticulata) for a short period (21 days) to an environmentally realistic concentration (1 ppb) of PFOA, a legacy PFAS, and its replacement compound, GenX, to assess their impact on reproductive traits and gene expression. Exposure to PFAS did not impair survival but instead caused sublethal effects. Overall, PFAS exposure caused changes in male sexual behaviour and had detrimental effects on sperm motility. Sublethal variations were also seen at the transcriptional level, with the modulation of genes involved in immune regulation, spermatogenesis, and oxidative stress. We also observed bioaccumulation of PFAS, which was higher for PFOA than for GenX. Our results offer a comprehensive comparison of these two PFAS and shed light on the toxicity of a newly emerging alternative to legacy PFAS. It is therefore evident that even at low concentrations and with short exposure, PFAS can have subtle yet significant effects on behaviour, fertility, and immunity. These findings underscore the potential ramifications of pollution under natural conditions and their impact on fish populations.

Evidence on the genotoxic and ecotoxic effects of PFOA, PFOS and their mixture on human lymphocytes and bacteria

Considering that the PFOA and PFOS are widely spread chemicals with harmful effects in human and environmental health as well as the increasing interest of the scientific community in the implications that might present especially when they co-exist, this study aims to assess their harmful impacts, both individually and as a mixture on human lymphocytes and aquatic microorganisms. The cytokinesis-block micronucleus (CBMN) assay was used to examine their potential for cytotoxicity and genotoxicity towards human cells, and Microtox assay using Aliivibrio fischeri assay was used to estimate the environmental risk. Regarding the human lymphocytes, the tested concentrations ranged between 250 and 1000 μg L-1, for all cases. PFOA increased slightly the frequency of micronuclei (MN) but without statistical significance. In the case of PFOS, our results showed a dose-dependent increase in the frequency of micronuclei which showed a statistically significant difference (p < 0.001) at 1000 μg L-1, which is the highest studied concentration. Regarding the CBPI index, statistically significant (p < 0.05, p < 0.01, and p < 0.001 respectively) differences were observed at all studied concentrations of PFOS, compared to the control. The mixture was found to be more cytotoxic and genotoxic than the individual tested compounds, causing a higher decrease at the CBPI index even in lower concentrations and increase at the MN frequencies. Aliivibrio fischeri was exposed to various concentrations in the range of 0.5 μg L-1- 20 mg L-1, for 5 and 15 min and significant increase in the inhibition percentage at the highest tested concentration of their mixture after 15 min was observed.

Detection and dietary risk of per- and polyfluoroalkyl substances in shellfish products from the coasts of Bohai Sea and South China Sea

Artificial per- and polyfluoroalkyl substances (PFASs) are widely distributed in the environment and are potentially harmful to human health. This study assessed the matrix effect of different shellfish on LC-MS analysis and the recoveries of PFASs in purified extracts purified by adding ENVI-Carb graphitized carbon black. Total 76 samples were collected from coastal cities of the Bohai Sea and South China Sea in China. Results showed that the signal response of perfluorocarboxylic acid increased with the length of fluorocarbon chains. ENVI-Carb can mitigate the shellfish matrix effects for analysis of PFASs. Ten PFASs components were detected in shellfish samples at concentrations ranging from 1.3 to 8.5 ng/g wet weight. The PFOA and PFHxS were the dominant components, and PFOA, PFTrDA and PFNA were detected at high rates of 58-93%. The highest levels of ∑PFASs were accumulated in clams, while the lowest levels were found in mussels. The dietary risk assessment indicated that PFASs potentially threaten human health via consumption of clam products in the Bohai Sea region. This study will improve the understanding of the contamination status and the dietary risk of PFASs in shellfish products along the coasts of Bohai Sea and South China Sea in China.

Magnetic Removal of Micro- and Nanoplastics from Water-from 100 nm to 100 µm Debris Size

Clean water is one of the most important resources of the planet but human-made contamination with diverse pollutants increases continuously. Microplastics (<5 mm diameter) which can have severe impacts on the environment, are present worldwide. Degradation processes lead to nanoplastics (<1 µm), which are potentially even more dangerous due to their increased bioavailability. State-of-the-art wastewater treatment plants show a deficit in effectively eliminating micro- and nanoplastics (MNP) from water, particularly in the case of nanoplastics. In this work, the magnetic removal of three different MNP types across three orders of magnitude in size (100 nm-100 µm) is investigated systematically. Superparamagnetic iron oxide nanoparticles (SPIONs) tend to attract oppositely charged MNPs and form aggregates that can be easily collected by a magnet. It shows that especially the smallest fractions (100-300 nm) can be separated in ordinary high numbers (1013  mg-1 SPION) while the highest mass is removed for MNP between 2.5 and 5 µm. The universal trend for all three types of MNP can be fitted with a derived model, which can make predictions for optimizing SPIONs for specific size ranges in the future.

Current state of knowledge of environmental occurrence, toxic effects, and advanced treatment of PFOS and PFOA

Per- and polyfluoroalkyl substances (PFAS) are anthropogenic synthetic compounds, with high chemical and thermal stability and a persistent, stable and bioaccumulative nature that renders them a potential hazard for the environment, its organisms, and humans alike. Perfluorooctane sulfonic acid (PFOS) and Perfluorooctanoic acid (PFOA) are the most well-known substances of this category and even though they are phased out from production they are still highly detectable in several environmental matrices. As a result, they have been spread globally in water sources, soil and biota exerting toxic and detrimental effects. Therefore, up and coming technologies, namely advanced oxidation processes (AOPs) and advanced reduction processes (ARPs) are being tested for their implementation in the degradation of these pollutants. Thus, the present review compiles the current knowledge on the occurrence of PFOS and PFOA in the environment, the various toxic effects they have induced in different organisms as well as the ability of AOPs and ARPs to diminish and/or eliminate them from the environment.

Environmental exposure to legacy and emerging per- and polyfluoroalkyl substances and endometriosis in women of childbearing age

Per- and polyfluoroalkyl substances (PFAS) are man-made chemicals known for their adverse effects on humans. Growing concern has risen regarding the reproductive toxicity of PFAS, but whether PFAS affect endometriosis remains to be explored. This hospital-based case-control study included 240 laparoscopic-confirmed endometriosis cases and 334 normal controls in China from 2014 to 2018. Concentrations of thirty-three legacy and emerging PFAS were measured in the plasma samples. Associations between single PFAS and endometriosis were estimated by binary logistic regression. The elastic net regression (ENR) model was used to identify dominant PFAS related to endometriosis. The joint effect of the PFAS mixture on endometriosis was assessed by principal component analysis (PCA), Bayesian kernel machine regression (BKMR), and quantile-based g-computation (q-gcomp). In the single-PFAS model, significant positive associations of PFOA [adjusted odds ratio (95 % CI): 1.22 (1.00, 1.51)], total PFOS [1.19 (1.05, 1.34)] and two branched PFOS isomers [1.16 (1.09, 1.22) for 1m-PFOS; 1.18 (1.04, 1.34) for 6m-PFOS] with increased endometriosis odds were observed. Mixture models showed that the joint effect of PFAS mixture on endometriosis was significant [1.24 (1.05, 1.48)], mainly driven by 1m-PFOS. The PFOS isomers profile suggested a PFOS precursor biotransformation source of 1m-PFOS in our population. Our study suggests that branched isomers of PFOS may be associated with endometriosis.

Sublethal perfluorooctanoic acid and perfluorooctanesulfonic acid delay C. elegans larval development and population growth but do not alter egg hatching

Perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) are polyfluoroalkyl substances (PFAS) used as surface coatings in manufacturing. Exposure to PFAS was shown to be correlated with infertility, low birth weight, and delayed aspects of pubertal development in mammals. Despite many correlational studies, there have been few direct investigations examining the link between PFAS exposure and early animal development. The aim of this study was to (1) examine the effects of PFOA on development and reproduction using the roundworm Caenorhabditis elegans, a model with a high predictive value for human reproductive toxicity and (2) compare observations to exposure to PFOS. PFAS exposure did not markedly alter egg hatching but delayed population growth, in part due to slower larval development. PFAS-exposed worms took longer to progress through larval stages to reach reproductive maturity, and this was not attributed to PFOA-induced toxicity to their food. Our results provide a robust benchmark for testing developmental and reproductive toxicity for other PFAS and PFAS-alternatives which continue to be used in manufacturing and released into the environment.

Functionalization strategies of metal-organic frameworks for biomedical applications and treatment of emerging pollutants: A review

One of the representative coordination polymers, metal-organic frameworks (MOFs) material, is of hotspot interest in the multi field thanks to their unique structural characteristics and properties. As a novel hierarchical structural class, MOFs show diverse topologies, intrinsic behaviors, flexibility, etc. However, bare MOFs have less desirable biofunction, high humid sensitivity and instability in water, restraining their efficiencies in biomedical and environmental applications. Thus, a structural modification is required to address such drawbacks. Herein, we pinpoint new strategies in the synthesis and functionalization of MOFs to meet demanding requirements in in vitro tests, i.e., antibacterial face masks against corona virus infection and in wound healing and nanocarriers for drug delivery in anticancer. Regarding the treatment of wastewater containing emerging pollutants such as POPs, PFAS, and PPCPs, functionalized MOFs showed excellent performance with high efficiency and selectivity. Challenges in toxicity, vast database of clinical trials for biomedical tests and production cost can be still presented. MOFs-based composites can be, however, a bright candidate for reasonable replacement of traditional nanomaterials in biomedical and wastewater treatment applications.