Perfluoroalkyl substances and endometriosis-related infertility in Chinese women

Per- and polyfluoroalkyl substances exposure is associated with polycystic ovary syndrome risk among women attending a fertility clinic

Previous studies reported that exposures to per- and polyfluoroalkyl substances (PFAS), largely in higher exposed populations, were associated with elevated risk of polycystic ovary syndrome (PCOS). However, studies evaluating PCOS risk in populations with lower background exposures to PFAS are limited. This study aimed to examine the associations between serum PFAS concentrations and PCOS risk among women attending a U.S. academic fertility clinic during 2005-2019. A total of 502 females who sought fertility evaluation and assisted reproduction treatments were included. Nine PFAS were quantified in non-fasting serum samples collected at study entry. Diagnosis of PCOS was based on the Rotterdam criteria. We used logistic regression to examine the odds ratio (OR) of PCOS in relation to individual PFAS concentrations (continuous and by tertiles) and quantile g-computation (QGC) and Bayesian Kernel Machine Regression (BKMR) to examine the joint associations of PFAS mixture with PCOS. Most participants were White and had a graduate degree or higher. Per doubling of serum perfluorooctane sulfonate (PFOS) and perfluorohexane sulfonate (PFHxS) concentrations were associated with higher odds of PCOS [OR (95%CI): 1.70 (1.06, 2.81) and 1.45 (1.02, 2.08) for PFOS and PFHxS respectively]. There was a dose-response relationship of PFOS with PCOS risk (p of trend by PFOS tertiles = 0.07). Both QGC and BKMR identified PFOS as the most important contributor among the mixture to PCOS risk. No clear joint effects were found for other PFAS or PFAS mixtures on PCOS risk. Our findings are consistent with existing evidence in populations with higher background PFAS concentrations and highlight the adverse effects of PFAS exposure on reproductive health. Findings can inform public health measures and clinical care to protect populations vulnerable to PCOS, in part, due to environmental exposures.

Exposure of women undergoing In-Vitro Fertilization to per-and polyfluoroalkyl substances: Evidence on negative effects on Fertilization and high-quality embryos

In April 2023, the World Health Organization (WHO) reported that 17.5% of the global adult population experience infertility. What may be the contribution of per-and polyfluoroalkyl (PFAS) to this global public health problem? This study explored the associations between in vitro fertilization (IVF) outcomes and plasma concentrations of individual PFAS and PFAS mixtures in women undergoing in vitro fertilization and embryo transfer (IVF-ET) and how these exposures might affect IVF outcomes. We analyzed 8 PFASs in plasma samples from women (N=259) who underwent IVF treatment. In multivariable generalized linear mixed models, there were statistically significant associations of higher plasma concentrations of PFNA with reduced numbers of total retrieved oocytes [12.486 (95%CI:-0.446,25.418), p trend=0.017], 2PN zygotes [6.467(95%CI:-2.034,14.968), p trend=0.007], and cleavage embryos [6.039(95%CI:-2.162,14.240), p trend=0.008]. Similarly, there was a continuous decline in the numbers of retrieved 2PN zygotes and cleavage embryos with increasing concentration of PFOS [6.467(95%CI:-2.034,14.968), p trend=0.009 and 6.039(95%CI:-2.162,14.240), p trend=0.031,respectively] and a negative association between PFHxS concentrations and clinical pregnancy during the initial cycles of frozen ET [0.525(95%CI:0.410,0.640), p trend=0.021]. To investigate the joint effect of PFAS mixtures, a confounder-adjusted BKMR model analysis showed inverse relationship between PFAS mixtures and the number of high-quality embryos, 2PN zygotes and cleavage embryos, to which the greatest contributors to the mixture effect are PFDeA and PFBS, respectively. It demonstrated that PFAS exposure might exert negative effects on oocyte yield, fertilization and high-quality embryo in women undergoing IVF. These findings suggest that exposure to PFAS may increase the risk of female infertility and further studies are needed to uncover the potential mechanisms underlying the reproductive effects associated with PFAS.

Multi-omics reveal disturbance of glucose homeostasis in pregnant rats exposed to short-chain perfluorobutanesulfonic acid

Perfluorobutanesulfonic acid (PFBS), a short-chain alternative to perfluorooctanesulfonic acid (PFOS), is widely used in various products and is increasingly present in environmental media and human bodies. Recent epidemiological findings have raised concerns about its potential adverse health effects, although the specific toxic mechanism remains unclear. This study aimed to investigate the metabolic toxicity of gestational PFBS exposure in maternal rats. Pregnant Sprague Dawley (SD) rats were randomly assigned to three groups and administered either 3% starch gel (control), 5, or 50 mg/kg bw·d PFBS. Oral glucose tolerance tests (OGTT) and lipid profiles were measured, and integrated omics analysis (transcriptomics and non-targeted metabolomics) was employed to identify changes in genes and metabolites and their relationships with metabolic phenotypes. The results revealed that rats exposed to 50 mg/kg bw·d PFBS exhibited a significant decrease in 1-h glucose levels and the area under the curve (AUC) of OGTT compared with the starch group. Transcriptomics analysis indicated significant alterations in gene expression related to cytochrome P450 exogenous metabolism, glutathione metabolism, bile acid secretion, tumor pathways, and retinol metabolism. Differentially expressed metabolites (DEMs) were enriched in pathways such as pyruvate metabolism, the glucagon signaling pathway, central carbon metabolism in cancer, and the citric acid cycle. Co-enrichment analysis and pairwise correlation analysis among genes, metabolites, and outcomes identified several differentially expressed genes (DEGs), including Gstm1, Kit, Adcy1, Gck, Ppp1r3c, Ppp1r3d, and DEMs such as fumaric acid, L-lactic acid, 4-hydroxynonenal, and acetylvalerenolic acid. These DEGs and DEMs may play a role in the modulation of glucolipid metabolic pathways. In conclusion, our results suggest that gestational exposure to PFBS may induce molecular perturbations in glucose homeostasis. These findings provide insights into the potential mechanisms contributing to the heightened risk of abnormal glucose tolerance associated with PFBS exposure.

Reproductive toxicity of PFOA, PFOS and their substitutes: A review based on epidemiological and toxicological evidence

Per- and polyfluoroalkyl substances (PFAS) have already drawn a lot of attention for their accumulation and reproductive toxicity in organisms. Perfluorooctanoic acid (PFOA) and perfluorooctanoic sulfonate (PFOS), two representative PFAS, are toxic to humans and animals. Due to their widespread use in environmental media with multiple toxicities, PFOA and PFOS have been banned in numerous countries, and many substitutes have been produced to meet market requirements. Unfortunately, most alternatives to PFOA and PFOS have proven to be cumulative and highly toxic. Of the reported multiple organ toxicities, reproductive toxicity deserves special attention. It has been confirmed through epidemiological studies that PFOS and PFOA are not only associated with reduced testosterone levels in humans, but also with an association with damage to the integrity of the blood testicular barrier. In addition, for women, PFOA and PFOS are correlated with abnormal sex hormone levels, and increase the risk of infertility and abnormal menstrual cycle. Nevertheless, there is controversial evidence on the epidemiological relationship that exists between PFOA and PFOS as well as sperm quality and reproductive hormones, while the evidence from animal studies is relatively consistent. Based on the published papers, the potential toxicity mechanisms for PFOA, PFOS and their substitutes were reviewed. For males, PFOA and PFOS may produce reproductive toxicity in the following five ways: (1) Apoptosis and autophagy in spermatogenic cells; (2) Apoptosis and differentiation disorders of Leydig cells; (3) Oxidative stress in sperm and disturbance of Ca2+ channels in sperm membrane; (4) Degradation of delicate intercellular junctions between Sertoli cells; (5) Activation of brain nuclei and shift of hypothalamic metabolome. For females, PFOA and PFOS may produce reproductive toxicity in the following five ways: (1) Damage to oocytes through oxidative stress; (2) Inhibition of corpus luteum function; (3) Inhibition of steroid hormone synthesis; (4) Damage to follicles by affecting gap junction intercellular communication (GJIC); (5) Inhibition of placental function. Besides, PFAS substitutes show similar reproductive toxicity with PFOA and PFOS, and are even more toxic to the placenta. Finally, based on the existing knowledge, future developments and direction of efforts in this field are suggested.

How Per- and Poly-Fluoroalkyl Substances Affect Gamete Viability and Fertilization Capability: Insights from the Literature

There has been emerging research linking per- and poly-fluoroalkyl substances (PFAS) to gamete viability and fertility. PFAS, prevalent in the environment and water supplies, undergo slow degradation due to their C-F bond and a long half-life (2.3-8.5 years). In females, PFAS inhibit the hypothalamic-pituitary-gonadal (HPG) axis, reducing follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels, leading to the inhibition of androgen and estradiol production. PFAS have been found to cause detrimental effects on egg quality through impairing folliculogenesis. In males, PFAS can impair sperm motility and morphology: two fundamental qualities of successful fertilization. PFAS exposure has been proven to inhibit testosterone production, sperm capacitation, and acrosomal reaction. After fertilization, the results of PFAS exposure to embryos have also been investigated, showing reduced development to the blastocyst stage. The aim of this review is to report the main findings in the literature on the impact of PFAS exposure to gamete competency and fertilization capability by highlighting key studies on both male and female fertility. We report that there is significant evidence demonstrating the negative impacts on fertility after PFAS exposure. At high doses, these environmentally abundant and widespread compounds can significantly affect human fertility.

Association of per- and polyfluoroalkyl substances with constipation: The National Health and Nutrition Examination Survey (2005-2010)

BACKGROUND

The impact of per- and polyfluoroalkyl substances (PFAS) on constipation, as mediated through gastrointestinal absorption and perturbations to the intestinal microecology, remains poorly understood.

OBJECTIVE

This study seeks to explain the relationship between PFAS and constipation.

METHODS

A total of 2945 adults from the National Health and Nutrition Examination Survey (NHANES) 2005-2010 were included in this study. Constipation was defined using the Bristol Stool Form Scale (BSFS) based on stool consistency. The relationship between PFAS and constipation was evaluated using weighted logistic regression and restricted cubic spline (RCS) analysis, while adjusting for confounding variables.

RESULTS

The weighted median concentration of total PFAS (ΣPFAS) was significantly lower in individuals with constipation (19.01 μg/L) compared to those without constipation (23.30 μg/L) (p < 0.0001). Subgroup analysis revealed that the cumulative effect of PFAS was more pronounced in the elderly, men, individuals with obesity, high school education or equivalent, and high-income individuals (p < 0.05). After adjusting for confounding factors, multivariable analysis demonstrated an inverse association between PFOA [OR (95% CI), 0.666(0.486,0.914)] and PFHxS [OR (95% CI), 0.699(0.482,1.015)], and constipation. None of the personal and lifestyle factors showed a significant correlation with this negative association, as confirmed by subgroup analysis and interaction testing (p for interaction > 0.05). The RCS analysis demonstrated a linear inverse relationship between PFAS levels and constipation.

CONCLUSION

The findings of this study provide evidence of a significant inverse correlation between serum concentrations of PFAS, particularly PFOA and PFHxS, and constipation.

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.

Exposure to select PFAS and PFAS mixtures alters response to platinum-based chemotherapy in endometrial cancer cell lines

BACKGROUND

Exposure to per- and poly-fluoroalkyl substances (PFAS) has been associated with significant alterations in female reproductive health. These include changes in menstrual cyclicity, timing of menarche and menopause, and fertility outcomes, as well as increased risk of endometriosis, all of which may contribute to an increased risk of endometrial cancer. The effect of PFAS on endometrial cancer cells, specifically altered treatment response and biology, however, remains poorly studied. Like other gynecologic malignancies, a key contributor to lethality in endometrial cancer is resistance to chemotherapeutics, specifically to platinum-based agents that are used as the standard of care for patients with advanced-stage and/or recurrent disease.

OBJECTIVES

To explore the effect of environmental exposures, specifically PFAS, on platinum-based chemotherapy response and mitochondrial function in endometrial cancer.

METHODS

HEC-1 and Ishikawa endometrial cancer cells were exposed to sub-cytotoxic nanomolar and micromolar concentrations of PFAS/PFAS mixtures and were treated with platinum-based chemotherapy. Survival fraction was measured 48-h post-chemotherapy treatment. Mitochondrial membrane potential was evaluated in both cell lines following exposure to PFAS ± chemotherapy treatment.

RESULTS

HEC-1 and Ishikawa cells displayed differing outcomes after PFAS exposure and chemotherapy treatment. Cells exposed to PFAS appeared to be less sensitive to carboplatin, with instances of increased survival fraction, indicative of platinum resistance, observed in HEC-1 cells. In Ishikawa cells treated with cisplatin, PFAS mixture exposure significantly decreased survival fraction. In both cell lines, increases in mitochondrial membrane potential were observed post-PFAS exposure ± chemotherapy treatment.

DISCUSSION

Exposure of endometrial cancer cell lines to PFAS/PFAS mixtures had varying effects on response to platinum-based chemotherapies. Increased survival fraction post-PFAS + carboplatin treatment suggests platinum resistance, while decreased survival fraction post-PFAS mixture + cisplatin exposure suggests enhanced therapeutic efficacy. Regardless of chemotherapy sensitivity status, mitochondrial membrane potential findings suggest that PFAS exposure may affect endometrial cancer cell mitochondrial functioning and should be explored further.

Transcriptomics integrated with metabolomics reveals perfluorobutane sulfonate (PFBS) exposure effect during pregnancy and lactation on lipid metabolism in rat offspring

Emerging epidemiological evidence indicates potential associations between gestational perfluorobutane sulfonate (PFBS) exposure and adverse metabolic outcomes in offspring. However, the underlying mechanisms remain unclear. Our study aimed to investigate PFBS exposure effects during pregnancy and lactation on rat offspring lipid profiles and the possible underlying mechanisms. Although the biochemical index difference including total cholesterol (TC), triglyceride (TG), high-density lipoprotein (HDL), low-density lipoprotein (LDL), alanine amino transaminase (ALT), aspartate amino transferase (AST), and fasting blood glucose between exposed groups and the control group was not significant, transcriptome analyses showed that the differentially expressed genes (DEGs) in the 50 mg/kg/day PFBS exposure group were significantly related to protein digestion and absorption, peroxisome proliferator activated-receptor (PPAR) signaling pathway, xenobiotic metabolism by cytochrome P450, glycine, serine and threonine metabolism, β-alanine metabolism, bile secretion, unsaturated fatty acid (FA) biosynthesis, and alanine, aspartate and glutamate metabolism. Untargeted metabolomics analyses identified 17 differential metabolites in the 50 mg/kg/day PFBS exposure group. Among these, phosphatidylserine [PS (18:0/22:6(4Z,7Z,10Z,13Z,16Z,19Z))], lysoPE (18:1(11Z)/0:0), and PS (14:0/20:4(5Z,8Z,11Z,14Z)) were significantly correlated with phospholipid metabolism disorders. Correlation analysis indicated the DEGs, including FA binding protein (Fabp4), spermine oxidase (Smox), Fabp2, acyl-CoA thioesterase 5 (Acot5), sarcosine dehydrogenase (Sardh), and amine oxidase, copper-containing 3 (Aoc3) that significantly enriched in xenobiotic metabolism by cytochrome P450 and glycine, serine, and threonine metabolism signaling pathways were highly related to the differential metabolite pantetheine 4'-phosphate. Pantetheine 4'-phosphate was significantly negatively associated with non-high-density lipoprotein (non-HDL) and TC levels. Collectively, our study indicated that maternal PFBS exposure at a relatively low level could alter gene expression and metabolic molecules in lipid metabolism-related pathway series in rat offspring, although the effects on metabolic phenotypes were not significant within the limited observational period, using group-wise and trend analyses.

Association of per- and polyfluoroalkyl substances with hepatic steatosis and metabolic dysfunction-associated fatty liver disease among patients with acute coronary syndrome

Etiology of hepatic steatosis and metabolic dysfunction-associated fatty liver disease (MAFLD) among acute coronary syndrome (ACS) remains unclear. Existing studies suggested the potential role of per- and polyfluoroalkyl substances (PFAS) in comorbidity of hepatic steatosis among ACS patients. Therefore, we conducted a cross-sectional study based on the ACS inpatients to assess the associations of plasma PFAS congeners and mixtures with hepatic steatosis and MAFLD. This study included 546 newly diagnosed ACS patients. Twelve PFAS were quantified using ultra-high-performance liquid chromatography-tandem mass spectrometry. Hepatic steatosis was defined by hepatic steatosis index (HSI). MAFLD was defined as the combination of hepatic steatosis based on the risk factor calculation with metabolic abnormalities. Generalized linear model was used to examine the associations of PFAS congeners with HSI and MAFLD. Adaptive elastic net (AENET) was further used for PFAS congeners selection. Mixture effects were also assessed with Bayesian kernel machine regression model (BKMR). Congeners analysis observed significant greater percent change of HSI for each doubling in PFOS (1.82%, 95% CI: 0.87%, 2.77%), PFHxS (1.17%, 95% CI: 0.46%, 1.89%) and total PFAS (1.84%, 95% CI: 0.56%, 3.14%). Moreover, each doubling in PFOS (OR=1.42, 95% CI: 1.13, 1.81), PFHxS (OR=1.31, 95% CI: 1.09, 1.59) and total PFAS (OR=1.43, 95% CI: 1.06, 1.94) was associated with increased risk of MAFLD. In AENET regression, only PFOS presented significant positive associations with HSI. Mixture analysis indicated significant positive associations between PFAS mixtures and HSI. This is the first study to demonstrate associations of PFAS congeners and mixtures with hepatic steatosis and MAFLD among ACS patients, which provides hypothesis into the mechanisms behind comorbidity of hepatic steatosis among ACS patients, as well as tertiary prevention of ACS.

Exposure to perfluoroalkyl substances and women's fertility outcomes in a Singaporean population-based preconception cohort

OBJECTIVES

Experimental models have demonstrated a link between exposure to perfluoroalkyl substances (PFAS) and decreased fertility and fecundability; however, human studies are scarce. We assessed the associations between preconception plasma PFAS concentrations and fertility outcomes in women.

METHODS

In a case-control study nested within the population-based Singapore Preconception Study of Long-Term Maternal and Child Outcomes (S-PRESTO), we measured PFAS in plasma collected in 2015-2017 from 382 women of reproductive age trying to conceive. Using Cox proportional hazards regression (fecundability ratios [FRs]) and logistic regression (odds ratios [ORs]) models, we assessed the associations of individual PFAS with time-to-pregnancy (TTP), and the likelihoods of clinical pregnancy and live birth, respectively, over one year of follow-up, adjusting for analytical batch, age, education, ethnicity, and parity. We used Bayesian weighted quantile sum (BWQS) regression to assess the associations of the PFAS mixture with fertility outcomes.

RESULTS

We found a 5-10 % reduction in fecundability per quartile increase of exposure to individual PFAS (FRs [95 % CIs] for clinical pregnancy = 0.90 [0.82, 0.98] for PFDA; 0.88 [0.79, 0.99] for PFOS; 0.95 [0.86, 1.06] for PFOA; 0.92 [0.84, 1.00] for PFHpA). We observed similar decreased odds of clinical pregnancy (ORs [95 % CIs] = 0.74 [0.56, 0.98] for PFDA; 0.76 [0.53, 1.09] for PFOS; 0.83 [0.59, 1.17] for PFOA; 0.92 [0.70, 1.22] for PFHpA) and live birth per quartile increases of individual PFAS and the PFAS mixture (ORs [95 % CIs] = 0.61 [0.37, 1.02] for clinical pregnancy, and 0.66 [0.40, 1.07] for live birth). Within the PFAS mixture, PFDA followed by PFOS, PFOA, and PFHpA were the biggest contributors to these associations. We found no evidence of association for PFHxS, PFNA, and PFHpS and the fertility outcomes examined.

CONCLUSIONS

Higher PFAS exposures may be associated with decreased fertility in women. The potential impact of ubiquitous PFAS exposures on infertility mechanisms requires further investigation.

Water a major source of endocrine-disrupting chemicals: An overview on the occurrence, implications on human health and bioremediation strategies

Endocrine disrupting chemicals (EDCs) are toxic compounds that occur naturally or are the output of anthropogenic activities that negatively impact both humans and wildlife. A number of diseases are associated with these disruptors, including reproductive disorders, cardiovascular disorders, kidney disease, neurological disorders, autoimmune disorders, and cancer. Due to their integral role in pharmaceuticals and cosmetics, packaging companies, agro-industries, pesticides, and plasticizers, the scientific awareness on natural and artificial EDCs are increasing. As these xenobiotic compounds tend to bioaccumulate in body tissues and may also persist longer in the environment, the concentrations of these organic compounds may increase far from their original point of concentrations. Water remains as the major sources of how humans and animals are exposed to EDCs. However, these toxic compounds cannot be completely biodegraded nor bioremediated from the aqueous medium with conventional treatment strategies thereby requiring much more efficient strategies to combat EDC contamination. Recently, genetically engineered microorganism, genome editing, and the knowledge of protein and metabolic engineering has revolutionized the field of bioremediation thereby helping to breakdown EDCs effectively. This review shed lights on understanding the importance of aquatic mediums as a source of EDCs exposure. Furthermore, the review sheds light on the consequences of these EDCs on human health as well as highlights the importance of different remediation and bioremediation approaches. Particular attention is paid to the recent trends and perspectives in order to attain sustainable approaches to the bioremediation of EDCs. Additionally, rigorous restrictions to preclude the discharge of estrogenic chemicals into the environment should be followed in efforts to combat EDC pollution.

Photodynamic Priming Overcomes Per- and Polyfluoroalkyl Substance (PFAS)-Induced Platinum Resistance in Ovarian Cancer†

Per- and polyfluoroalkyl substances (PFAS) are widespread environmental contaminants linked to adverse outcomes, including for female reproductive biology and related cancers. We recently reported, for the first time, that PFAS induce platinum resistance in ovarian cancer, potentially through altered mitochondrial function. Platinum resistance is a major barrier in the management of ovarian cancer, necessitating complementary therapeutic approaches. Photodynamic therapy (PDT) is a light-based treatment modality that reverses platinum resistance and synergizes with platinum-based chemotherapy. The present study is the first to demonstrate the ability of photodynamic priming (PDP), a low-dose, sub-cytotoxic variant of PDT, to overcome PFAS-induced platinum resistance. Comparative studies of PDP efficacy using either benzoporphyrin derivative (BPD) or 5-aminolevulinic acid-induced protoporphyrin IX (PpIX) were conducted in two human ovarian cancer cell lines (NIH:OVCAR-3 and Caov-3). BPD and PpIX are clinically approved photosensitizers that preferentially localize to, or are partly synthesized in, mitochondria. PDP overcomes carboplatin resistance in PFAS-exposed ovarian cancer cells, demonstrating the feasibility of this approach to target the deleterious effects of environmental contaminants. Decreased survival fraction in PDP + carboplatin treated cells was accompanied by decreased mitochondrial membrane potential, suggesting that PDP modulates the mitochondrial membrane, reducing membrane potential and re-sensitizing ovarian cancer cells to carboplatin.

Alteration of hepato-lipidomic homeostasis in A/J mice fed an environmentally relevant PFAS mixture

In the present study, we have investigated liver lipid homeostasis and corresponding changes in transcript and functional product levels in A/J mice exposed to environmental relevant concentration of per- and polyfluoroalkyl substances (PFAS) mixture. Mice were fed environmentally relevant concentrations of a PFAS mixture during a period of 10 weeks. The concentrations of the 8 individual PFAS in the mixture were chosen based on measured concentrations in earthworms at a Norwegian skiing area. Our data show high liver accumulation of ∑PFAS in exposed mice, which paralleled significant elevation in body weight and hepatosomatic index (HSI) of male mice. UPC2 -MS/MS analysis in both positive and negative mode, respectively, indicated significant differences between control and exposure groups in the liver of exposed mice. Principal component analysis (PCA) of the features revealed separation of control and exposure groups in both sexes. From the significantly differential 207 lipids, only 72 were identified and shown to belong to eight different lipid classes. PCA of fatty acids (FAs) profile showed a clear separation between control and PFAS exposure groups in both female and male mice, with differential abundant levels of 5 and 4 hydrolyzed FAs, respectively. Transcript and protein analysis of genes associated with lipid homeostasis (ppar-α and β, lxr-α and β, rxr, fasn and srebp) showed that PFAS exposure produced sex- and individual response related alterations. Glutathione reductase (Gr) activity showed exposure-related changes in both female and male mice, compared with controls. Overall, the present study has demonstrated changes in lipid metabolism after PFAS exposure, showing that PFAS accumulation in the liver resulted to hepatotoxic effects, potential interference with membrane lipid profile and homeostasis, and oxidative stress. Given the structural similarity with FAs, interaction between PFAS and nuclear receptors such as PPARs may have severe consequences for general health and physiology in exposed animals and humans.

Maternal exposure to perfluorobutane sulfonate (PFBS) during pregnancy: evidence of adverse maternal and fetoplacental effects in New Zealand White (NZW) rabbits

Perfluorobutanesulfonic acid (PFBS) is a replacement for perfluorooctanesulfonic acid (PFOS) that is increasingly detected in drinking water and human serum. Higher PFBS exposure is associated with risk for preeclampsia, the leading cause of maternal and infant morbidity and mortality in the United States. This study investigated relevant maternal and fetal health outcomes after gestational exposure to PFBS in a New Zealand White rabbit model. Nulliparous female rabbits were supplied drinking water containing 0 mg/l (control), 10 mg/l (low), or 100 mg/l (high) PFBS. Maternal blood pressure, body weights, liver and kidney weights histopathology, clinical chemistry panels, and thyroid hormone levels were evaluated. Fetal endpoints evaluated at necropsy included viability, body weights, crown-rump length, and liver and kidney histopathology, whereas placenta endpoints included weight, morphology, histopathology, and full transcriptome RNA sequencing. PFBS-high dose dams exhibited significant changes in blood pressure markers, seen through increased pulse pressure and renal resistive index measures, as well as kidney histopathological changes. Fetuses from these dams showed decreased crown-rump length. Statistical analysis of placental weight via a mixed model statistical approach identified a significant interaction term between PFBS high dose and fetal sex, suggesting a sex-specific effect on placental weight. RNA sequencing identified the dysregulation of angiotensin (AGT) in PFBS high-dose placentas. These results suggest that PFBS exposure during gestation leads to adverse maternal outcomes, such as renal injury and hypertension, and fetal outcomes, including decreased growth parameters and adverse placenta function. These outcomes raise concerns about pregnant women's exposure to PFBS and pregnancy outcomes.

Contact to perfluoroalkyl substances and thyroid health effects: A meta-analysis directing on pregnancy

In vivo, in vitro, and epidemiological evidence suggests that perfluoroalkyl substances (PFAS) may alter thyroid function in human health, with negative effects on maternal and fetal development outcomes. However, data on the effects of PFAS on thyroid hormones remain controversial. Here, we conducted a meta-analysis of 13 eligible studies searched from Embase, PubMed, and Web of Science by July 10, 2022, to explore the relationship between maternal exposure to PFAS and thyroid health effects, including thyroid stimulating hormone (TSH), triiodothyronine (TT3), thyroxin (TT4), free T3 (FT3), and free T4 (FT4). The estimated values (β) and the corresponding confidence intervals (95%CI) were extracted for analysis. The tests for heterogeneity, sensitivity and publication bias between studies were performed using Stata 15.0. The combined results showed a positive association between changes in TSH and exposure to perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA) and perfluorodecanoic acid (PFDA), with no significant correlation observed between changes in other thyroid hormones and exposure to PFAS. This difference was attributed to sample size, region, sample type, body mass index (BMI), and gestational week. Our data recommend verifying the relationship between PFAS exposure and thyroid health effects in a large sample population cohort in future studies. In addition, health care should be taken into account in early and mid-pregnancy.

An exposure to endocrine active persistent pollutants and endometriosis - a review of current epidemiological studies

Widespread exposure to persistent pollutants can disrupt the bodies' natural endocrine functions and contribute to reproductive diseases like endometriosis. In this review, we focus at the relationship between endocrine-disrupting chemicals (EDCs), including metals and trace elements, organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polybrominated biphenyls (PBBs), poly-brominated diphenyl ethers (PBDEs), polychlorinated dibenzodioxin (PCDDs), polychlorinated dibenzofurans (PCDFs), and per- and polyfluoroalkyl substances (PFAS) exposure and risk of endometriosis. Relevant studies from the last 10 years by November 2022 were identified by searching Pubmed, Web of Science, and Scopus. The cohort and case-control studies that reported effect size with 95% confidence intervals (CIs) of EDC exposure and endometriosis were selected. Twenty three articles examining the relationship between endometriosis and exposure to persistent EDCs were considered. Most of the studies indicated association with exposure to persistent chemicals and development of endometriosis. The consistent results were found in case of lead, PCB-28, PCB-138, PCB-153, PCB-180, PCB-201, 1,2,3,7,8 - PeCDD, 2,3,4,7,8 - PeCDF and all described OCPs, showing the increased risk of endometriosis. These results support that exposure to certain EDCs, including OCPs, PCBs, PBBs, PBDEs, PFAS, and lead increase the risk of endometriosis.

The effects of perfluoroalkyl and polyfluoroalkyl substances on female fertility: A systematic review and meta-analysis

OBJECTIVE

The reproductive toxicity of perfluoroalkyl and polyfluoroalkyl substances (PFAS) has been verified in both animal and in vitro experiments, however, the association between PFAS and female fertility remains contradictory in population studies. Therefore, in this systematic review and meta-analysis, we evaluated the effects of PFAS on female fertility based on population evidence.

METHODS

Electronic searches of the Web of Science, PubMed, The Cochrane Library, and Embase databases were conducted (from inception to March 2022) to collect observational studies related to PFAS and female fertility. Two evaluators independently screened the literature, extracted information and evaluated the risk of bias for the included studies, meta-analysis was performed using R software.

RESULTS

A total of 5468 records were searched and 13 articles fully met the inclusion criteria. Meta-analysis showed that perfluorooctanoic acid (PFOA) exposure was negatively associated with the female fecundability odds ratio (FOR = 0.88, 95% confidence interval (Cl) [0.78; 0.98]) and positively associated with the odds ratio for infertility (OR = 1.33, 95%Cl [1.03; 1.73]). Perfluorooctane sulfonate (PFOS) exposure was negatively associated with the fecundability odds ratio (FOR = 0.94, 95% CI [0.90; 0.98]). Pooled effect values for perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), and perfluorohexane sulfonate (PFHxS) exposure did not find sufficient evidence for an association with female fertility.

CONCLUSION

Based on the evidence provided by the current study, increased levels of PFAS exposure are associated with reduced fertility in women, this was characterized by a reduction in fecundability odds ratio and an increase in odds ratio for infertility. This finding could partially explain the decline in female fertility and provide insight into risk assessment when manufacturing products containing PFAS.

Toxicity of perfluooctane sulfonate (PFOS) and perfluorobutane sulfonate (PFBS) to Scenedesmus obliquus: Photosynthetic characteristics, oxidative damage and transcriptome analysis

With the wide application as an alternative for perfluorooctane sulfonate (PFOS), perfluorobutane sulfonate (PFBS) has been frequently detected in the aquatic environment. However, the aquatic toxicity of PFBS is still poorly understood. The present work studied the aquatic toxicity of PFBS using freshwater algae Scenedesmus obliquus (S. obliquus) as indicator, and the toxicity of PFOS was also examined for comparison. The results showed that PFBS exhibited much lower toxicity to S. obliquus than PFOS. The EC₅₀ value was higher than 1800 mg L^-1 after 7 days of exposure to PFBS. By contrast, a much lower EC₅₀ value of 136.69 mg L^-1 was obtained for PFOS. Photosynthetic efficiency analyzed by chlorophyll fluorescence also verified that PFOS induced a higher toxic effect on the algae than PFBS. The malondialdehyde, catalase and superoxide dismutase results indicate that PFOS exposure led to the accumulation of ROS, which caused oxidative damage to the algae, thereby resulting in the inhibition in the growth and photosynthesis of the algae. Furthermore, transcriptome analysis indicates that the significant down-regulation of key genes related to photosynthesis induced by PFOS was the fundamental mechanism for the inhibition in photosynthetic efficiency and biomass growth of S. obliquus.

Association between Perfluoroalkyl and Polyfluoroalkyl Substances and Women's Infertility, NHANES 2013-2016

Perfluoroalkyl and polyfluoroalkyl substances (PFASs) are widely used in consumer products. However, the role of PFAS in infertility is still poorly understood. A total of 788 women from the 2013-2016 nationally representative NHANES were included to explore the association between PFAS exposure and self-reported infertility. Six PFAS, including PFDE, PFNA, PFHxS, n-PFOA, n-PFOS, and Sm-PFOS, were detected by online SPE-HPLC-TIS-MS/MS. We used the generalized linear regression model (GLM), generalized additive models (GAM), and Bayesian kernel machine regression (BKMR) to assess the single effects, non-linear relationships, and mixed effects on women's infertility, respectively. The prevalence of self-reported infertility was 15.54% in this study. In GLM, n-PFOA showed a negative association with self-reported infertility in women for the Q3 (OR: 0.396, 95% CI: 0.119, 0.788) and Q4 (OR: 0.380, 95% CI: 0.172-0.842) compared with Q1 (p for trend = 0.013). A negative trend was also observed in n-PFOS and ∑PFOS (p for trend < 0.05). In GAM, a non-linear relationship was revealed in Sm-PFOS, which exhibits a U-shaped relationship. The BKMR model indicated that there might be a joint effect between PFAS and women's infertility, to which PFNA contributed the highest effect (PIP = 0.435). Moreover, age stratification analysis showed a different dose-response curve in under and above 35 years old. Women under the age of 35 have a more noticeable U-shaped relationship with infertility. Therefore, the relatively low level of mixed PFAS exposure was negatively associated with self-reported infertility in women in general, and the impact of PFAS on infertility may vary among women of different age groups. Further studies are needed to determine the etiological relationship.

Transcriptomic Interaction between Young Fecal Transplantation and Perfluorobutanesulfonate in Aged Zebrafish Gonads

The transfer of young fecal microbiota has been found to significantly refresh the reproductive endocrine system and effectively ameliorate the toxicity of perfluorobutanesulfonate (PFBS) in aged zebrafish recipients. However, the mechanisms underlying the antagonistic action of young fecal microbiota against the reproductive endocrine toxicity of PFBS remain largely unknown. In this study, the aged zebrafish were transplanted with feces from young donors and then exposed to PFBS for 14 days. After exposure, the shift in the transcriptomic fingerprint of the gonads was profiled by using high-throughput sequencing, aiming to provide mechanistic clues into the interactive mode of action between young fecal transplantation and PFBS's innate toxicity. The results showed that the gene transcription pattern associated with protein and lipid synthesis in the gonads of the aged individuals was quite different from the young counterparts. It was intriguing that the transplantation of young feces established a youth-like transcriptomic phenotype in the elderly recipients, thus attenuating the functional decline and maintaining a healthy aging state of the gonads. A sex specificity response was clearly observed. Compared to the aged females, more metabolic pathways (e.g., glycine, serine, and threonine metabolism; glyoxylate and dicarboxylate metabolism; pyrimidine metabolism) were significantly enriched in aged males receiving young feces transplants. PFBS dramatically altered the transcriptome of aged testes, while a much milder effect was observable in aged ovaries. Accordingly, a suite of biological processes related to germ cell proliferation were disrupted by PFBS in aged males, including the ECM-receptor interaction, retinol metabolism, and folate biosynthesis. In aged ovaries exposed to PFBS, mainly the fatty acid and arginine biosynthesis pathway was significantly affected. However, these transcriptomic disorders caused by PFBS were largely mitigated in aged gonads by transferring young feces. Overall, the present findings highlighted the potential of young fecal transplantation to prevent the functional compromise of gonads resulting from aging and PFBS.

Exposure of Preconception Couples to Legacy and Emerging Per- and Polyfluoroalkyl Substances: Variations Within and Between Couples

Exploration of the exposure of preconception couples to per- and polyfluoroalkyl substances (PFAS), as well as the most important influencing factors, promotes the understanding of the joint effects of parental exposure on reproductive health. In the present study, a total of 938 preconception couples recruited through the Shanghai Birth Cohort were investigated for the variations of PFAS exposure and contributing factors within and between couples. While linear perfluorooctanoic acid (n-PFOA, median 20.4 ng/mL) and linear perfluorooctanesulfonic acid (n-PFOS, 12.1 ng/mL) remained dominant in plasma, emerging PFAS, particularly 6:2 chlorinated polyfluorinated ether sulfonate (10.5 ng/mL), 6:2 polyfluoroalkyl phosphate diester (0.41 ng/mL), and branched PFOS or PFOA isomers, were also frequently detected. Although individual PFAS were generally correlated within couples, gender differences significantly existed in the concentrations of most individual PFAS and isomer profiles of PFOS and PFOA. Men generally exhibited higher plasma concentrations than their partners, likely reflecting gender-specific elimination pathway and kinetics. Couple-based PFAS exposure also varied greatly. After adjustment for individual factors, several household factors, including annual household income, dwelling floor type, drinking water source, and living near farmlands, were found to be associated with couple-based PFAS exposure. Our study constitutes one of the few studies addressing couple-based exposure to PFAS and lays a solid ground for further assessment of the impacts of parental exposure on reproductive health.

Environmental pollution, a hidden culprit for health issues

The environmental and health impacts from the massive discharge of chemicals and subsequent pollution have been gaining increasing public concern. The unintended exposure to different pollutants, such as heavy metals, air pollutants and organic chemicals, may cause diverse deleterious effects on human bodies, resulting in the incidence and progression of different diseases. The article reviewed the outbreak of environmental pollution-related public health emergencies, the epidemiological evidence on certain pollution-correlated health effects, and the pathological studies on specific pollutant exposure. By recalling the notable historical life-threatening disasters incurred by local chemical pollution, the damning evidence was presented to criminate certain pollutants as the main culprit for the given health issues. The epidemiological data on the prevalence of some common diseases revealed a variety of environmental pollutants to blame, such as endocrine-disrupting chemicals (EDCs), fine particulate matters (PMs) and heavy metals. The retrospection of toxicological studies provided illustrative clues for evaluating ambient pollutant-induced health risks. Overall, environmental pollution, as the hidden culprit, should answer for the increasing public health burden, and more efforts are highly encouraged to strive to explore the cause-and-effect relationships through extensive epidemiological and pathological studies.

Per- and poly-fluoroalkyl substances (PFAS) and female reproductive outcomes: PFAS elimination, endocrine-mediated effects, and disease

Per- and poly-fluoroalkyl substances (PFAS) are widespread environmental contaminants frequently detected in drinking water supplies worldwide that have been linked to a variety of adverse reproductive health outcomes in women. Compared to men, reproductive health effects in women are generally understudied while global trends in female reproduction rates are declining. Many factors may contribute to the observed decline in female reproduction, one of which is environmental contaminant exposure. PFAS have been used in home, food storage, personal care and industrial products for decades. Despite the phase-out of some legacy PFAS due to their environmental persistence and adverse health effects, alternative, short-chain and legacy PFAS mixtures will continue to pollute water and air and adversely influence women's health. Studies have shown that both long- and short-chain PFAS disrupt normal reproductive function in women through altering hormone secretion, menstrual cyclicity, and fertility. Here, we summarize the role of a variety of PFAS and PFAS mixtures in female reproductive tract dysfunction and disease. Since these chemicals may affect reproductive tissues directly or indirectly through endocrine disruption, the role of PFAS in breast, thyroid, and hypothalamic-pituitary-gonadal axis function are also discussed as the interplay between these tissues may be critical in understanding the long-term reproductive health effects of PFAS in women. A major research gap is the need for mechanism of action data - the targets for PFAS in the female reproductive and endocrine systems are not evident, but the effects are many. Given the global decline in female fecundity and the ability of PFAS to negatively impact female reproductive health, further studies are needed to examine effects on endocrine target tissues involved in the onset of reproductive disorders of women.

Early pregnancy loss: Do Per- and polyfluoroalkyl substances matter?

Per- and poly-fluorinated substances (PFASs) with endocrine disrupting effect can efficiently transfer across the blood-follicle barrier. However, it is still controversial and attracting extensive public concern that whether PFASs can affect the human fertility potential. Therefore, we aimed to analyze the associations of women's exposure to PFASs with pregnancy loss, the relevant processes of fertilization, zygote implantation, and embryo development by using a prospective cohort study. The women undergoing in vitro fertilization-embryo transfer (IVF-ET) treatment were recruited in Beijing City (Beijing Center) and Yantai City (Yantai Center) in China during 2015-2017. A total of 305 women were recruited before the IVF-ET treatment. Twelve PFASs were measured in their serum samples collected in the day before the IVF-ET treatment, as well as in the human chorionic gonadotropin (hCG) day. The three IVF-ET outcomes were included, i.e. hCG test negative, clinical pregnancy failure (CPF), and preclinical spontaneous abortion. Nine serum PFASs had detection rate of >70% in Beijing and Yantai centers. The exposure patterns to PFASs between these two centers were overall different. For Beijing Center, we only found a positive association of perflurodecanoic acid (PFDA) with the risk of CPF [RR = 2.28 (95 %CI: 1.02-5.11)], but there is a reverse trend in Yantai Center with [RR = 0.45 (95 %CI: 0.23-0.85)]. However, the serum concentration of PFDA in Beijing Center was relatively lower than that of Yantai Center. Other significant associations of the detected PFASs with the IVF-ET outcomes, or with the relevant clinical processes, were not found. The multi-pollutant regression model of the Bayesian kernel machine regression suggested that there were no joint effects between various PFASs on the concerned outcomes. Overall, we suggest that most PFAS were not associated with early pregnancy loss at the current exposure levels. As for the PFDA, there may exist susceptibility of different populations.

Perfluoroalkyl substances (PFAS) in drinking water and risk for polycystic ovarian syndrome, uterine leiomyoma, and endometriosis: A Swedish cohort study

BACKGROUND

Perfluorinated substances (PFAS) are chemicals with endocrine disruptive properties that may interfere with the female reproductive system. However, few studies have explored the association between benign gynecological diseases and high PFAS exposure.

OBJECTIVES

The aim of this study was to investigate the possible associations between PFAS exposure and subsequent diagnosis of polycystic ovarian syndrome (PCOS), uterine leiomyoma (fibroids), and endometriosis in a cohort exposed to PFAS through drinking water.

MATERIAL AND METHODS

In 2013, high levels (with sum of PFAS above 10,000 ng/L), dominated by perfluorooctanesulfonic acid (PFOS) and perfluorohexane sulfonic acid (PFHxS), were found in the drinking water from one of the two waterworks in Ronneby, Sweden. The contamination came from firefighting foams used at a nearby airfield. Females of all ages (n = 29,106) who had ever resided in the municipality between 1985 and 2013 formed a cohort. Individual exposure was assessed based on municipality waterworks distribution data linked to annual residential address data; 27% of the females had ever lived at an address with PFAS-contaminated water. Gynecological health outcomes were retrieved from the Swedish National Patient Register. The Cox proportional hazards model was used to estimate the association between exposure and each diagnosis.

RESULTS

There were in all 161 cases of PCOS, 1,122 cases of uterine leiomyoma, and 373 cases of endometriosis. In women aged 20-50 years (n = 18,503), those with the highest estimated PFAS exposure had increased hazard ratios (HR) for PCOS (HR = 2.18; 95% confidence interval (CI) 1.43, 3.34) and uterine leiomyoma (HR = 1.28; 95% CI 0.95, 1.74). No increased HR for endometriosis was found (HR = 0.74; 95% CI 0.42, 1.29).

CONCLUSIONS

Exposure to high levels of PFAS in drinking water was associated with increased risk of PCOS and possibly uterine leiomyoma, but not endometriosis. The findings for PCOS are consistent with prior studies reporting positive associations between PCOS and PFAS exposure at background levels.

Chemosensory Dysfunction Induced by Environmental Pollutants and Its Potential As a Novel Neurotoxicological Indicator: A Review

Air pollution composed of the complex interactions among particular matter, chemicals, and pathogens is an emerging and global environmental issue that closely correlates with a variety of diseases and adverse health effects, especially increasing incidences of neurodegenerative diseases. However, as one of the prevalent health outcomes of air pollution, chemosensory dysfunction has not attracted enough concern until recently. During the COVID-19 pandemic, multiple scientific studies emphasized the plausibly essential roles of the chemosensory system in the airborne transmission airway of viruses into the human body, which can also be utilized by pollutants. In this Review, in addition to summarizing current progress regarding the contributions of traditional air pollutants to chemosensory dysfunction, we highlight the roles of emerging contaminants. We not only sum up clarified mechanisms, such as inflammation and apoptosis but also discuss some not yet completely identified mechanisms, e.g., disruption of olfactory signal transduction. Although the existing evidence is not overwhelming, the chemosensory system is expected to be a useful indicator in neurotoxicology and neural diseases based on accumulating studies that continually excavate the deep link between chemosensory dysfunction and neurodegenerative diseases. Finally, we argue the importance of studies concerning chemosensory dysfunction in understanding the health effects of air pollution and provide comments for some future directions of relevant research.

Nitric oxide mediates disruption of human placental trophoblast invasion induced by perfluorobutane sulfonate

Perfluorobutane sulfonate (PFBS), an emerging pollutant, is associated with disruption of placental functions and adverse birth outcomes. However, the precise mechanism of this disruption remains unclear. Extravillous trophoblasts make up the majority of cells in the placenta, and have invasive abilities, which plays a critical role in a successful pregnancy. It has been reported that inducible nitric oxide (iNOS) and nitric oxide (NO) signaling is associated with trophoblast migration and invasion. In this study, PFBS exposure was found to enhance trophoblast invasion and increase matrix metalloproteinase 9 (MMP-9) levels. Additionally, PFBS upregulated iNOS levels and stimulated NO generation. iNOS inhibitor treatment attenuated the increased invasion of trophoblasts and MMP-9 expression induced by PFBS. Extracellular signal-regulated kinase (ERK) phosphorylation was also enhanced by PFBS exposure. In the presence of an ERK pathway inhibitor, however, the increases in trophoblast invasion, the induction of NO production, iNOS expression and MMP-9 expression induced by PFBS were attenuated. Taken together, these results suggest that iNOS/NO signaling is triggered by activation of the ERK signaling pathway, and that iNOS/NO signaling mediates PFBS-induced stimulation of trophoblast invasion.

Perfluoroalkyl substances in drinking water sources along the Yangtze River in Jiangsu Province, China: Human health and ecological risk assessment

Perfluoroalkyl substances (PFASs) in source water is of growing concern for its adverse effects on human health and wildlife as well. The Yangtze River is the vital drinking water source in Jiangsu Province of China, but little attention has been paid on PFASs. The occurrence, spatial distribution and temporal trend of PFASs in 21 water sources along the Jiangsu section of the Yangtze River was investigated with sampling from 2018 to 2020. Moreover, health risk of PFASs was assessed by estimated intake dose and derived tolerable intake dose, while ecological risk was assessed by selected effect concentration and environmental exposure. PFASs concentrations in source water ranged from 12.0 to 128 ng/L, with perfluorooctanoic acid (PFOA) as the dominated congener. Fluorine chemical industry lead to a great increase of perfluorohexanoic acid (PFHxA) in its nearest water source. The estimated daily intake of PFASs through drinking was 0.54 and 0.82 ng/kg bw/day for adults and children. The major health risk was from perfluorooctane sulfonate (PFOS) and PFOA for their toxicity on liver, reproduction, development and immunity, with the maximum hazard quotient of 0.029 and 0.043 for adults and children in the worst scenario. The ecological risks from PFASs on nine species groups ranged from 2.7 × 10-10 to 5.2. PFOA and Perfluorobutane sulfonate (PFBS) were causing significant risk on wildlife, particularly on worms, mussels, and fish, which may further influence the structure and processes in the foodweb. Overall, PFASs, especially PFOS, PFOA and PFBS, induced considerable risk on human health and aquatic species in some hotspot area. It would be necessary to include them into monitoring in China and develop standards for different protection purposes.

Perfluoroalkyl substances and sex hormones in postmenopausal women: NHANES 2013-2016

BACKGROUND

Although an alteration in sex hormones has been linked to perfluoroalkyl substances (PFAS) in premenopausal women and girls, whether such associations exist in postmenopausal women remains uncertain.

OBJECTS

To examine the associations between serum PFAS concentrations and sex hormone levels in postmenopausal women.

METHODS

Data from the National Health and Nutrition Examination Survey (NHANES) 2013-2016 waves were used. A total of 706 postmenopausal women with information on serum PFAS [perfluorohexane sulfonic acid (PFHxS), pefluorodecanoic acid (PFDA); perfluorononanoic acid (PFNA); linear perfluorooctanoate (n-PFOA); linear perfluorooctane sulfonate (n-PFOS); monomethyl branched isomers of PFOS (Sm-PFOS)], sex hormones indicators [e.g., total testosterone (TT), estradiol (E₂) and sex hormone binding globulin (SHBG)] as well as selected covariates were included. An indicator of circulating free testosterone (FT), and ratio of TT to E₂ (TT/E₂) were generated. Multiple linear regression accounting for the primary sampling unit, strata, and environmental sampling weights of PFAS was used for association analyses. Effect modification by obesity and type of menopause was explored via stratified analyses as well as the testing of interaction terms. Principal component analysis (PCA) and Bayesian kernel machine regression (BKMR) were conducted to assess these relationships in a multiple PFAS exposure setting.

RESULTS

After adjusting for potential confounders, total perfluorooctanoate (TPFOA: n-PFOA + Sb-PFOA) and total perfluorooctane sulfonate (TPFOS: n-PFOS + Sm-PFOS), and their linear and branched isomers were positively associated with two androgen indicators (i.e., TT and FT). PCA results revealed that the principal component (PC) composed of n-PFOA was positively associated with ln (TT) [β = 0.09, 95% confidential interval (CI): 0.02, 0.16; per ln-ng/mL increase in exposure], and ln (FT) (β = 0.12, 95% CI: 0.05, 0.2) in overweight/obese [body mass index (BMI) ≥ 25 kg/m²] women, but not in those with BMI < 25 kg/m². Additionally, among overweight/obese women, PFHxS was positively associated with androgens and negatively with ln (SHBG) (β = -0.06, 95% CI: -0.12, -0.01). The PC composed of Sm-PFOS, n-PFOS, and PFHxS was positively associated with ln (TT) levels among overweight/obese women. Results from BKMR also confirmed the findings on n-PFOA and PFHxS.

CONCLUSIONS

Our study indicates that n-PFOA and PFHxS were positively associated with levels of several androgen indicators in postmenopausal women, particularly among overweight/obese ones. Given the higher risk of cardiometabolic diseases associated with elevated levels of androgens in postmenopausal women, future studies are needed to explore the potential underlying mechanisms.

Per- and Polyfluoroalkyl Substance Toxicity and Human Health Review: Current State of Knowledge and Strategies for Informing Future Research

Reports of environmental and human health impacts of per- and polyfluoroalkyl substances (PFAS) have greatly increased in the peer-reviewed literature. The goals of the present review are to assess the state of the science regarding toxicological effects of PFAS and to develop strategies for advancing knowledge on the health effects of this large family of chemicals. Currently, much of the toxicity data available for PFAS are for a handful of chemicals, primarily legacy PFAS such as perfluorooctanoic acid and perfluorooctane sulfonate. Epidemiological studies have revealed associations between exposure to specific PFAS and a variety of health effects, including altered immune and thyroid function, liver disease, lipid and insulin dysregulation, kidney disease, adverse reproductive and developmental outcomes, and cancer. Concordance with experimental animal data exists for many of these effects. However, information on modes of action and adverse outcome pathways must be expanded, and profound differences in PFAS toxicokinetic properties must be considered in understanding differences in responses between the sexes and among species and life stages. With many health effects noted for a relatively few example compounds and hundreds of other PFAS in commerce lacking toxicity data, more contemporary and high-throughput approaches such as read-across, molecular dynamics, and protein modeling are proposed to accelerate the development of toxicity information on emerging and legacy PFAS, individually and as mixtures. In addition, an appropriate degree of precaution, given what is already known from the PFAS examples noted, may be needed to protect human health. Environ Toxicol Chem 2021;40:606-630. © 2020 SETAC.

Parental plasma concentrations of perfluoroalkyl substances and In Vitro fertilization outcomes

Perfluoroalkyl substances (PFAS) are known to be endocrine-disrupting compounds, but are nevertheless widely used in consumer and industrial products and have been detected globally in human and wildlife. Data from animal and epidemiological studies suggest that PFAS may affect human fertility. This led us to consider whether maternal or paternal plasma PFAS had effects on in vitro fertilization (IVF) outcomes. The study population consisted of 96 couples who underwent IVF treatment in 2017 due to tubal factor infertility. The concentrations of 10 PFAS in blood samples from both male and female partners were measured. Poisson regression with log link was performed to evaluate the association between the tertiles of PFAS concentrations and numbers of retrieved oocytes, mature oocytes, two-pronuclei (2 PN) zygotes, and good-quality embryos, while multiple linear regression models were used to investigate the correlation between plasma PFAS and semen parameters. Multivariable logistic regression was used to evaluate the association between the tertiles of PFAS concentrations and clinical outcomes. It was found that maternal plasma concentrations of perfluorooctanoic acid (PFOA) were negatively associated with the numbers of retrieved oocytes (p_trend = 0.023), mature oocytes (p_trend = 0.015), 2 PN zygotes (p_trend = 0.014), and good-quality embryos (p_trend = 0.012). Higher paternal plasma PFOA concentrations were found to be significantly associated with reduced numbers of 2 PN zygotes (p_trend = 0.047). None of the maternal or paternal PFAS were significantly associated with the probability of implantation, clinical pregnancy, or live birth. To our knowledge, the present study is the first to assess the association between parental exposure to PFAS and IVF outcomes. Our results suggest the potential reproductive effects of PFAS on both men and women, and that exposure to PFAS may negatively affect IVF outcomes. Future studies, particularly with large sample size cohorts, are needed to confirm these findings.

Endocrine disruption by PFAS: A major concern associated with legacy and replacement substances

Perand poly-fluorinated alkyl substances (PFAS) have been used for decades in a great variety of processes and products by virtue of their exceptional properties, versatility and chemical stability. Nevertheless, it is increasingly recognized that these substances can represent a serious hazard to human health and living organisms due to their persistence, long-range transport potential and tendency to accumulate in biota. For this reason, some efforts have been made across the EU to identify alternative molecules, with a shorter carbon chain and theoretically safer profile, that might replace the previous generation of legacy PFAS. Unfortunately, this strategy has not been entirely successful and serious concerns are still posed by PFAS in different human populations. Among others, an emerging aspect is represented by the adverse effects that both legacy and alternative PFAS can exert on the human endocrine system, with respect to vulnerable target subpopulations. In this review we will briefly summarize PFAS properties, uses and environmental fate, focusing on their effects on human reproductive capacity and fertility, body weight control and obesity as well as thyroid function.

Perfluorooctanoic acid (PFOA) inhibits the gap junction intercellular communication and induces apoptosis in human ovarian granulosa cells

Perfluorooctanoic acid (PFOA) has attracted widespread research attention as it is very stable, bioaccumulates, and causes reproductive toxicity. Data from several animal experiments and epidemiological studies indicate that female fertility may decline because of ovarian granulosa cell (GC) apoptosis as oocyte quality is positively associated with effective gap junctional intercellular communication (GJIC) between GCs. To the best of our knowledge, however, no previous trials have been conducted or reported on the effects of PFOA exposure on apoptosis induction in human GCs. Moreover, the roles of GJIC in GC survival and in the induction of apoptosis in GCs by PFOA remain unclear. To test this, we cultured human GCs in vitro and treated them with 0 μM, 0.3 μM, 3 μM, or 30 μM PFOA for 24 h. We also treated a human ovarian GC line (KGN) with various combinations of PFOA, retinoic acid (RA, 10 μM), and carbenoxolone disodium (CBX, 50 mM). Our findings showed that PFOA lowered human GC viability and increased apoptosis. The effects of CBX resemble those of PFOA. The combination of PFOA and CBX enhances the inhibition of GJIC by PFOA and promotes apoptosis. The effects of RA are the opposite to those of PFOA. The combination of RA and PFOA mitigates PFOA-induced GJIC inhibition and reduces apoptosis. The observed expression levels of apoptosis-related proteins were consistent with the aforementioned findings. Hence, our study demonstrated that PFOA may induce human ovarian GC apoptosis by inhibiting GJIC.

Exposure to perfluorobutane sulfonate and perfluorooctanesulfonic acid disrupts the production of angiogenesis factors and stress responses in human placental syncytiotrophoblast

Poly- and per-fluoroalkyl substances (PFAS) have attracted widespread attention in recent years due to their bioaccumulation, toxicity, and ubiquitous nature. We and others have reported that maternal exposure to PFAS is associated with adverse birth outcomes due to altered placental functions. In this study, we investigated the effects of two major PFAS compounds, perfluorobutane sulfonate (PFBS) and perfluorooctanesulfonic acid (PFOS), on the regulation of the production of angiogenic factors and stress response in placental multinucleated syncytial BeWo cells using qRT-PCR and ELISA. Using this in vitro model, we showed that 1) PFOS or PFBS treatment did not seem to interrupt BeWo cell fusion through syncytins; 2) Exposure to PFOS at 10 μM decreased a potent angiogenic factor PlGF gene expression, which is implicated in preeclampsia; 3) Exposure to either PFOS or PFBS significantly decreased the production of CGB7 and hCG except hCG secretion in PFOS (10 nM) and PFBS (100 nM) treatment groups; 4) Exposure to PFOS (10 μM) increased the gene expression of the stress response molecules CRH while neither PFOS nor PFBS treatment affected a stress mitigation factor 11β-HSD2 expression. Our results demonstrate that exposure to PFOS or PFBS impacts several key pathways involved in placental cell functions. PFOS seems more potent than PFBS. These novel findings provide a potential explanation for the adverse reproductive complications associated with prenatal exposure to PFOS or PFBS, including preeclampsia and contribute to our knowledge of the reproductive toxicity of PFAS, specifically PFOS and PFBS.

Perfluorooctanesulfonic acid (PFOS) and perfluorobutanesulfonic acid (PFBS) impaired reproduction and altered offspring physiological functions in Caenorhabditis elegans

Perfluorobutanesulfonic acid (PFBS), a shorter chain Per- and polyfluoroalkyl substances (PFASs) cognate of perfluorooctanesulfonic acid (PFOS), has been used as replacement for the toxic surfactant PFOS. However, emerging evidences suggest safety concerns for PFBS and its effect on reproductive health is still understudied. Therefore, the current work aimed to investigate the effect of PFBS, in comparison to PFOS, on reproductive health using Caenorhabditis elegans as an in vivo animal model. PFOS (≥10 μM) and PFBS (≥1000 μM) significantly impaired the reproduction capacity of C. elegans, represented as reduced brood size (total egg number) and progeny number (hatched offspring number), without affecting the hatchability. Additionally, the preconception exposure of PFOS and PFBS significantly altered the embryonic nutrient loading and composition, which further led to abnormalities in growth rate, body size and locomotive activity in F1 offspring. Though the effective exposure concentration of PFBS was approximately 100 times higher than PFOS, the internal concentration of PFBS was lower than that of PFOS to produce the similar effects of PFOS. In conclusion, PFOS and PFBS significantly impaired the reproductive capacities in C. elegans and the preconception exposure of these two compounds can lead to offspring physiological dysfunctions.

Per- and poly-fluoroalkyl substances (PFASs) in follicular fluid from women experiencing infertility in Australia

Per- and poly-fluoroalkyl substances (PFASs) have been widely used and detected in human matrices. Evidence that PFAS exposure may be associated with adverse human reproductive health effects exists, however, data is limited. The use of a human matrix such as follicular fluid to determine chemical exposure, along with reproductive data will be used to investigate if there is a relationship between PFAS exposure and human fertility.

OBJECTIVE

This study aims to: (1) assess if associations exist between PFAS concentrations and/or age and fertilisation rate (as determined in follicular fluid of women in Australia who received assisted reproductive treatment (ART)); and (2) assess if associations exist between PFAS concentrations and infertility aetiology.

METHODS

Follicular fluids were originally collected from participants who underwent fully stimulated ART treatment cycles at an in vitro fertilisation (IVF) clinic in the period 2006-2009 and 2010-11 in Queensland, Australia. The samples were available for analysis of 32 PFASs including perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), perfluorohexane sulfonate (PFHxS), and perfluorononanoic acid (PFNA) using high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). 97 samples were matched with limited demographic data (age and fertilisation rate) and five infertility factors (three known female factors): 1) endometriosis, 2) polycystic ovarian syndrome (PCOS), and 3) genital tract infections - tubal/pelvic inflammation disease; as well as 4) male factor, and 5) idiopathic or unknown from either males or females. SPSS was used for linear regression analysis.

RESULTS

PFASs were detected in all follicular fluid samples with the mean concentrations of PFOS and PFOA, 4.9, and 2.4 ng/ml, respectively. A lower fertilisation rate was observed at higher age when age was added as a covariate, but there was no relationship between PFAS concentrations and fertilisation rate. There were few statistically significant associations between PFAS concentrations in follicular fluid and infertility factors. Log-transformed PFHxS concentrations were lower in females with endometriosis (factor 1) than in women who had reported 'male factors' as a reason of infertility, while PFHpA was higher in women who had infertile due to female factors (factor 1-3) compared to those who had infertile due to male factor.

CONCLUSION

PFASs were detected in follicular fluid of Australian women who had been treated at an IVF clinic. PFAS exposure found in follicular fluids is linked to increased risk of some infertility factors, and increased age was associated with decreased fertilisation rate in our data. But there was no relationship between PFAS and ferlitisation rate. Further large-scale investigations of PFAS and health effects including infertility are warranted.

Perfluorobutane sulfonate exposure disrupted human placental cytotrophoblast cell proliferation and invasion involving in dysregulating preeclampsia related genes

We reported that maternal PFBS, an emerging pollutant, exposure is positively associated with preeclampsia which can result from aberrant trophoblasts invasion and subsequent placental ischemia. In this study, we investigated the effects of PFBS on trophoblasts proliferation/invasion and signaling pathways. We exposed a human trophoblast line, HTR8/SVneo, to PFBS. Cell viability, proliferation, and cell cycle were evaluated by the MTS assay, Ki-67 staining, and flow cytometry, respectively. We assessed cell migration and invasion with live-cell imaging-based migration assay and matrigel invasion assay, respectively. Signaling pathways were examined by Western blot, RNA-seq, and qPCR. PFBS exposure interrupted cell proliferation and invasion in a dose-dependent manner. PFBS (100 μM) did not cause cell death but instead significant cell proliferation without cell cycle disruption. PFBS (10 and 100 μM) decreased cell migration and invasion, while PFBS (0.1 μM) significantly increased cell invasion but not migration. Further, RNA-seq analysis identified dysregulated HIF-1α target genes that are relevant to cell proliferation/invasion and preeclampsia, while Western Blot data showed the activation of HIF-1α, but not Notch, ERK1/2, (PI3K)AKT, and P38 pathways. PBFS exposure altered trophoblast cell proliferation/invasion which might be mediated by preeclampsia-related genes, suggesting a possible association between prenatal PFBS exposure and adverse placentation.

Bioaccumulation of perfluoroalkyl substances in greenhouse vegetables with long-term groundwater irrigation near fluorochemical plants in Fuxin, China

The levels of perfluoroalkyl substances (PFASs) have been growing progressively in the groundwater beneath a fluorochemical industrial park (FIP) in Fuxin of China recently, however, little information is available about whether long-term irrigation with local groundwater could have a potential effect on the bioaccumulation of PFASs in greenhouse vegetables near the FIP. In the present study, groundwater, soil, and vegetable samples were collected from Fuxin with five sampling campaigns during a period of 40 days, and ten target analytes of PFASs in all the samples were analyzed via high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). As the dominant PFAS contaminants, perfluorooctanoic acid (PFOA) and perfluorobutane sulfonate (PFBS) in groundwater samples were determined with the maximum levels of 2.47 and 32.4 μg L^-1, respectively. Furthermore, perfluorobutanoic acid (PFBA), PFOA, and PFBS were the major PFASs in greenhouse samples of soil (up to 6.1, 6.8, and 46 ng g dry weight (dw)^-1), tomato (up to 87, 1.7, and 13 ng g dw^-1), and cucumber (up to 63, 2.6, and 15 ng g dw^-1), which were significantly correlated with those in groundwater samples, indicating PFAS contaminations could be introduced into soil and vegetables in the greenhouse through long-term groundwater irrigation. In addition, all the levels of three main PFAS analytes in soil and vegetables presented an overall increasing trend over the period of vegetable growth. The bioaccumulation efficiencies for PFAS contaminants from soil to vegetables were negatively associated with the carbon chain length in PFASs. According to the reference dose (RfD) for PFBA, PFOA, and PFBS from the Minnesota Department of Health (MDH), daily intakes of those three analytes by rural residents in Fuxin were lower than the respective RfD via consumption of greenhouse tomatoes and cucumbers so far. However, long-term surveillance would be focused on greenhouse vegetables near the Fuxin FIP to prevent potential health risks of local residents from increasing PFAS contaminations.

Endocrine-disrupting chemicals: implications for human health

Since reports published in 2015 and 2016 identified 15 probable exposure-outcome associations, there has been an increase in studies in humans of exposure to endocrine-disrupting chemicals (EDCs) and a deepened understanding of their effects on human health. In this Series paper, we have reviewed subsequent additions to the literature and identified new exposure-outcome associations with substantial human evidence. Evidence is particularly strong for relations between perfluoroalkyl substances and child and adult obesity, impaired glucose tolerance, gestational diabetes, reduced birthweight, reduced semen quality, polycystic ovarian syndrome, endometriosis, and breast cancer. Evidence also exists for relations between bisphenols and adult diabetes, reduced semen quality, and polycystic ovarian syndrome; phthalates and prematurity, reduced anogenital distance in boys, childhood obesity, and impaired glucose tolerance; organophosphate pesticides and reduced semen quality; and occupational exposure to pesticides and prostate cancer. Greater evidence has accumulated than was previously identified for cognitive deficits and attention-deficit disorder in children following prenatal exposure to bisphenol A, organophosphate pesticides, and polybrominated flame retardants. Although systematic evaluation is needed of the probability and strength of these exposure-outcome relations, the growing evidence supports urgent action to reduce exposure to EDCs.

Per- and poly-fluoroalkyl substances and bone mineral density: Results from the Bayesian weighted quantile sum regression

Per- and poly-fluoroalkyl substances (PFAS) are chemicals, detected in 95% of Americans, that induce osteotoxicity and modulate hormones, thereby influencing bone health. Previous studies found associations between individual PFAS and bone mineral density in adults but did not analyze their combined effects.

OBJECTIVE

To extend weighted quantile sum (WQS) regression to a Bayesian framework (Bayesian extension of the WQS regression [BWQS]) and determine the association between a mixture of serum PFAS and mineral density in lumbar spine, total, and neck femur in 499 adults from the 2013 to 2014 National Health and Nutrition Examination Survey (NHANES).

METHODS

We used BWQS to assess the combined association of eight PFAS, as a mixture, with bone mineral density in adults. As secondary analyses, we focused on vulnerable populations (men over 50 years and postmenopausal women). Analyses were adjusted for sociodemographic factors. Sensitivity analyses included bone mineral density associations with individual compounds and results from WQS regressions.

RESULTS

The mean age was 55 years old (SD = 1) with average spine, total, and neck femur mineral densities of 1.01 (SD = 0.01), 0.95 (SD = 0.01), and 0.78 (SD = 0.01) gm/cm2, respectively. PFAS mixture levels showed no evidence of association with mineral density (spine: β = -0.004; 95% credible interval [CrI] = -0.04, 0.04; total femur: β = 0.002; 95% CrI = -0.04, 0.05; femur neck: β = 0.005; 95%CrI = -0.03, 0.04) in the overall population. Results were also null in vulnerable populations. Findings were consistent across sensitivity analyses.

CONCLUSIONS

We introduced a Bayesian extension of WQS and found no evidence of the association between PFAS mixture and bone mineral density.

Exposure of female mice to perfluorooctanoic acid suppresses hypothalamic kisspeptin-reproductive endocrine system through enhanced hepatic fibroblast growth factor 21 synthesis, leading to ovulation failure and prolonged dioestrus

Perfluorooctanoic acid (PFOA) is widely used in household applications. High-dose exposure to PFOA has been associated with increased risks of infertility and premature ovarian insufficiency in woman. PFOA can alter hepatic gene expression by activating peroxisome proliferator-activated receptor α (PPARα). The present study investigated whether exposure to PFOA via PPARα activation alters the synthesis of hepatic fibroblast growth factor 21 (FGF21) to disturb female neuroendocrine and reproductive function. In the present study, we show that the oral administration of PFOA (2 or 5 mg kg^-1 ) in adult female mice (PFOA mice) caused prolonged dioestrous, a reduction in the number of corpora lutea and decreased levels of hypothalamic gonadotrophin-releasing hormone, serum progesterone and luteinising hormone (LH). Exposure to PFOA decreased the expression of vasopressin in the suprachiasmatic nucleus (SCN) and kisspeptin in the anteroventral periventricular nucleus (AVPV) with deficits in preovulation or oestrogen-induced LH surge. PFOA via activation of PPARα increased dose-dependently hepatic FGF21 expression, leading to elevated serum and hypothalamic FGF21 concentrations. Treatment of PFOA mice with the PPARα antagonist GW6471 or the FGF21 inhibitor PD173074 rescued SCN vasopressin and AVPV-kisspeptin expression. Either administration of GW6471 and PD173074 or treatment with vasopressin and the G protein coupled receptor 54 agonist kisspeptin-10 in PFOA-mice was able to recover the regular oestrous cycle, ovulation ability, LH surge production and reproductive hormone levels. The present study provides in vivo evidence that exposure to PFOA (≥2 mg kg^-1 ) in mice causes down-regulation of the kisspeptin-reproductive endocrine system by enhancing PPARα-mediated hepatic FGF21 expression. The liver-brain reproductive endocrine disorder caused by PFOA exposure may lead to prolonged dioestrous and ovulation failure.

Exposure of adult mice to perfluorobutanesulfonate impacts ovarian functions through hypothyroxinemia leading to down-regulation of Akt-mTOR signaling

Perfluorobutanesulfonate (PFBS), a short-chain perfluoroalkyl substance, is used in many industrial products. Preliminary evidence suggests that exposure to PFBS may increase the risk of infertility. The aim of this study was to investigate the influence of PFBS on ovarian function. Herein, we show that exposure of adult female mice to PFBS (200 mg/kg/day) (PFBS-mice) caused a decrease in the levels of serum total triiodothyronine and thyroxine, which depended on the activation of peroxisome proliferator-activated receptor α (PPARα). The numbers of secondary, early antral and antral follicles were reduced in PFBS-mice with an increase in the atretic follicles, and these changes were recovered by the replacement of L-thyroxinein or the treatment with PPARα antagonist GW6471. PFBS-induced hypothyroxinemia led to a decrease in the levels of Akt, mTOR and p70S6K phosphorylation in ovarian granular cells and cumulus cells, which suppressed the proliferation of these cells and enhanced autophagic death of granular cells and cumulus cells. The levels of serum estradiol and progesterone were reduced in PFBS-mice with a low expression of the steroidogenic genes Star and P450scc in ovarian tissues, which were sensitive to the replacement of L-thyroxinein or the blockade of PPARα. The results indicate that exposure to PFBS (≥200 mg/kg/day) through reducing thyroid hormones causes down-regulation of Akt-mTOR signaling in granular cells and cumulus cells, leading to the deficits in the development of follicles and the biosynthesis of ovarian hormones.

Endocrine Disruptors in Water and Their Effects on the Reproductive System

Anthropogenic contaminants in water can impose risks to reproductive health. Most of these compounds are known to be endocrine disrupting chemicals (EDCs). EDCs can impact the endocrine system and subsequently impair the development and fertility of non-human animals and humans. The source of chemical contamination in water is diverse, originating from byproducts formed during water disinfection processes, release from industry and livestock activity, or therapeutic drugs released into sewage. This review discusses the occurrence of EDCs in water such as disinfection byproducts, fluorinated compounds, bisphenol A, phthalates, pesticides, and estrogens, and it outlines their adverse reproductive effects in non-human animals and humans.

Association of urinary metabolites of organophosphate and pyrethroid insecticides, and phenoxy herbicides with endometriosis

Endometriosis is a hormone-responsive gynecologic disease, signifying its connotations across a woman's life span. Previous studies suggested that endocrine disrupting chemicals were risk factors for endometriosis. Nevertheless, little is known on exposure to organophosphate, pyrethroid and phenoxy acid pesticides on endometriosis diagnosis. In this study, we determined the concentrations of 11 pesticides, metabolites of organophosphate and pyrethroid insecticides, and phenoxy herbicides, in urine collected from 619 reproductive-age women in Utah and California, using liquid chromatography-tandem mass spectrometry. The association of urinary concentrations of pesticides with an increase in the odds of endometriosis diagnosis was examined in 594 women who underwent laparoscopy/laparotomy (operative cohort: n = 471) or pelvic magnetic resonance imaging (population cohort: n = 123), during 2007-2009. 2-Isopropyl-4-methyl-6-hydroxypyrimidine (IMPY), malathion dicarboxylic acid (MDA), para-nitrophenol (PNP), 3,5,6-trichloro-2-pyridinol (TCPY), 3-phenoxybenzoic acid (3-PBA), and 2,4-dichlorophenoxyacetic acid (2,4-D) were detected in ≥95% of the urine samples analyzed. Urinary concentrations of IMPY, MDA, PNP, 3-PBA and 2,4-D tended to be higher in younger, non-Hispanic black, nulliparous and less affluent women. IMPY was the most dominant compound in urine followed by PNP and TCPY. When women in the 4th quartile of IMPY and the 2nd quartile of TCPY concentrations (μg/g creatinine) were compared with women in the 1st quartile, the odds ratios (ORs) for diagnosis of endometriosis increased significantly in unadjusted models (IMPY OR = 1.89, 95% confidence interval (Cl) = 1.12-3.20; TCPY OR = 1.65, 95% Cl = 1.02-2.69) for the operative (n = 471) and entire data set (n = 594), respectively. Our results suggest that exposure to elevated concentrations of diazinon (the parent compound of IMPY) and chlorpyrifos and chlorpyrifos-methyl (parent compounds of TCPY) may be associated with endometriosis.

Antioxidant CoQ10 Restores Fertility by Rescuing Bisphenol A-Induced Oxidative DNA Damage in the Caenorhabditis elegans Germline

Endocrine-disrupting chemicals are ubiquitously present in our environment, but the mechanisms by which they adversely affect human reproductive health and strategies to circumvent their effects remain largely unknown. Here, we show in Caenorhabditis elegans that supplementation with the antioxidant Coenzyme Q10 (CoQ10) rescues the reprotoxicity induced by the widely used plasticizer and endocrine disruptor bisphenol A (BPA), in part by neutralizing DNA damage resulting from oxidative stress. CoQ10 significantly reduces BPA-induced elevated levels of germ cell apoptosis, phosphorylated checkpoint kinase 1 (CHK-1), double-strand breaks (DSBs), and chromosome defects in diakinesis oocytes. BPA-induced oxidative stress, mitochondrial dysfunction, and increased gene expression of antioxidant enzymes in the germline are counteracted by CoQ10. Finally, CoQ10 treatment also reduced the levels of aneuploid embryos and BPA-induced defects observed in early embryonic divisions. We propose that CoQ10 may counteract BPA-induced reprotoxicity through the scavenging of reactive oxygen species and free radicals, and that this natural antioxidant could constitute a low-risk and low-cost strategy to attenuate the impact on fertility by BPA.

Perfluoroalkyl substances in groundwater and home-produced vegetables and eggs around a fluorochemical industrial park in China

High-level contaminations of perfluoroalkyl substances (PFASs) were determined in both surface water and groundwater around a fluorochemical industrial park (FIP) in Fuxin, China, over the past few years. Yet little is known about whether groundwater PFAS contaminations in Fuxin could be introduced into home-produced vegetables and eggs in local residences via the application of groundwater for the irrigation or feeding purposes. In the present study, ten PFAS analytes were analyzed via high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) to investigate the extent of PFAS contaminations in the groundwater, soil, and home-produced vegetable and egg samples derived from Fuxin. As the predominant PFAS contaminants, perfluorobutane sulfonate (PFBS) and perfluorooctanoic acid (PFOA) were observed in groundwater beneath the Fuxin FIP with the maximum concentrations of 21.2 and 2.51 µg/L, respectively, which were 24-fold and 5-fold higher individually compared to those reported previously. Both of them were also higher than the updated health advisories for PFBS and PFOA in drinking water issued by the Minnesota Department of Health and the US Environmental Protection Agency. In addition, short-chain PFASs involving perfluorobutanoic acid (PFBA) and PFBS were found to be the major contaminants in both home-produced vegetables and eggs from the residential gardens around the FIP. Statistically significant relationships were determined between the levels of PFBA, PFOA, and PFBS in local groundwater and those observed in home-produced vegetables (p = 0.003, p = 0.025, and p < 0.001), suggesting potential entry of those PFAS contaminants into home-produced vegetables via irrigation with groundwater beneath the FIP.

Perfluoroalkyl substances exposure and risk of polycystic ovarian syndrome related infertility in Chinese women

Perfluoroalkyl substances (PFASs) are a family of synthetic, fluorinated organic compounds. They have been widely used in industrial applications and consumer products and widespread in the environment, wildlife and human. Experimental and epidemiologic evidence suggested that PFASs are capable of interfering with endocrine processes and have potential reproductive and developmental toxicities. Polycystic ovarian syndrome (PCOS), one of the main reasons of female infertility, is a common endocrine disorder in reproductive age women. We performed a case-control study to evaluate associations between PCOS-related infertility and PFASs concentrations in plasma. A total of 180 infertile PCOS-cases and 187 healthy controls were recruited from the Center for Reproductive Medicine of Shandong University. Blood specimens were collected at enrollment and analyzed for ten PFASs using liquid chromatography-tandem mass spectrometry. Multivariable logistic regression procedure was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for each PFAS. Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) were the dominant PFASs in the plasma of participants, with the median concentration of 5.07 ng/mL and 4.05 ng/mL, respectively. The median levels of individual PFAS were not significantly different between PCOS-cases and controls. While adjusted for the potential confounders (age, BMI, household income, education level, employment status, age at menarche, menstrual volume), the plasma concentration of perfluorododecanoic acid (PFDoA), a 12 carbons lengths of perfluorocarboxylic acids, was associated with a significantly increased risk of PCOS-related infertility (medium vs low tertile: OR = 2.36, 95% CI: 1.12, 4.99, P = 0.02; high vs low tertile: OR = 3.04, 95% CI: 1.19, 7.67, P = 0.02), with the P trend 0.01. No significant relationship was observed between PCOS-related infertility and other PFAS analytes in the adjusted model, despite perfluoroundecanoic acid showed a negative association (P trend 0.03). The potential reproductive health effects of PFASs and the underlying mechanisms merit further investigation in the future.

Association of Perfluoroalkyl and Polyfluoroalkyl Substances With Premature Ovarian Insufficiency in Chinese Women

CONTEXT

Perfluoroalkyl and polyfluoroalkyl substances (PFASs), a group of ubiquitous environmental chemicals with properties of endocrine disruption, are often detectable in humans.

OBJECTIVE

The current study investigated the association between exposure to PFAS and primary ovarian insufficiency (POI).

DESIGN, PATIENTS, INTERVENTIONS, AND MAIN OUTCOME MEASURES

Levels of plasma PFAS were measured in 120 Chinese women with overt POI and 120 healthy control subjects from 2013 to 2016. Associations between PFAS levels and odds of POI, as well as hormonal profiles, were evaluated using multiple logistic regression and multiple linear regression models.

RESULTS

Levels of perfluorooctanate (PFOA), perfluorooctane sulfonate (PFOS), and perfluorohexanesulfonate (PFHxS) were positively associated with the risks of POI (highest vs. lowest tertile, PFOA: OR, 3.80; 95% CI, 1.92-7.49; PFOS: OR, 2.81; 95% CI, 1.46-5.41; PFHxS: OR, 6.63; 95% CI, 3.22-13.65). In patients with POI, levels of PFOS and PFHxS exposure were positively associated with FSH (PFOS: adjusted β, 0.26; 95% CI, 0.15 to 0.38; PFHxS: adjusted β, 0.16; 95% CI, 0.04 to 0.28) and negatively associated with estradiol (PFOS: adjusted β, -0.30; 95% CI, -0.47 to -0.12; PFHxS: adjusted β, -0.19; 95% CI, -0.37 to -0.02). Exposure to PFOS and PFOA was associated with elevation of prolactin (PFOS: adjusted β, 0.17; 95% CI, 0.06 to 0.29; PFOA: adjusted β, 0.16; 95% CI, 0.01 to 0.30) or with a decrease of free triiodothyronine (PFOS: adjusted β, -0.88; 95% CI, -1.64 to -0.09; PFOA: adjusted β, -0.90; 95% CI, -1.88 to 0.09) and thyroxine (PFOS: adjusted β, -2.99; 95% CI, -4.52 to -1.46; PFOA: adjusted β, -3.42; 95% CI, -5.39 to -1.46).

CONCLUSION

High exposure to PFOA, PFOS, and PFHxS is associated with increased risk of POI in humans.