Exposure and dietary sources of bisphenol A (BPA) and BPA-alternatives among mothers in the APrON cohort study

Maternal exposure to bisphenols, phthalates, perfluoroalkyl acids, and trace elements and their associations with gestational diabetes mellitus in the APrON cohort

The increasing global prevalence of gestational diabetes mellitus (GDM) has been hypothesized to be associated with maternal exposure to environmental chemicals. Here, among 420 women participating in the Alberta Pregnancy Outcomes and Nutrition (APrON) cohort study, we examined associations between GDM and second trimester blood or urine concentrations of endocrine disrupting chemicals (EDCs): bisphenol-A (BPA), bisphenol-S (BPS), twelve phthalate metabolites, eight perfluoroalkyl acids (PFAAs), and eleven trace elements. Fifteen (3.57%) of the women were diagnosed with GDM, and associations between the environmental chemical exposures and GDM diagnosis were examined using multiple logistic and LASSO regression analyses in single- and multi-chemical exposure models, respectively. In single chemical exposure models, BPA and mercury were associated with increased odds of GDM, while a significant inverse association was observed for zinc. Double-LASSO regression analysis selected mercury (AOR: 1.51, CI: 1.12-2.02), zinc (AOR: 0.017, CI: 0.0005-0.56), and perfluoroundecanoic acid (PFUnA), a PFAAs, (AOR: 0.43, CI: 0.19-0.94) as the best predictors of GDM. The combined data for this Canadian cohort suggest that second trimester blood mercury was a robust predictor of GDM diagnosis, whereas blood zinc and PFUnA were protective factors. Research into mechanisms that underlie the associations between mercury, zinc, PFUnA, and the development of GDM is needed.

Association between bisphenol A exposure and cardiometabolic outcomes: A longitudinal approach

Increased cardiometabolic risk is associated with abnormalities in blood biomarkers profile and adiposity measurements. Some substances found in the food matrix and the environment, called endocrine-disrupting chemicals, may impair cardiometabolic health in the early and later stages of life. Bisphenol A (BPA) is a food contaminant that migrates from food contact materials and may act as an endocrine disruptor, negatively affecting human health. The present work aims to longitudinally assess the association between BPA exposure and cardiometabolic outcomes, considering data from Portuguese population-based birth cohort Generation XXI. Blood insulin (0.06stdβ; 95 %CI:0.03,0.09) and insulin resistance (0.05stdβ; 95 %CI:0.02,0.08) presented a significant longitudinal association with BPA daily exposure after adjustment for important variables and energy. The same findings were observed for fat mass (0.03stdβ; 95 %CI 0.01,0.06) and waist circumference (0.06stdβ; 95 %CI:0.04,0.08). For z-BMI, a significant cross-sectional (0.03stdβ; 95 %CI:0.01,0.04) and longitudinal (0.02stdβ; 95 %CI:0.00,0.04) association was found. This was the first study assessing the association between BPA exposure and health outcomes from childhood to adolescence. We found an association between BPA exposure and increased blood insulin level, insulin resistance, fat mass percentage, waist circumference and z-BMI. Our results point to the need to reduce exposure to BPA in the early stages of life.

Environmental triggers of autoimmunity: The association between bisphenol analogues and systemic lupus erythematosus

The aim of this research was to examine the correlation between the exposure to bisphenol analogues (BPs), such as bisphenol A (BPA), bisphenol F (BPF), and bisphenol S (BPS), and the risk of developing systemic lupus erythematosus (SLE). Ultra performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) was utilized to measure the levels of BPA, BPF, and BPS in the urine of 168 female participants diagnosed with SLE and 175 female participants who were deemed healthy controls. Logistic regression models were utilized to assess the connections between levels of bisphenol and the risk of SLE. The findings indicated that levels of BPA and BPF in the urine of individuals with SLE were markedly elevated compared to those in the control group. Higher exposure to BPA and BPF exhibited positive dose-response relationships with increased SLE risk. No significant associations were identified between BPS and the risk of SLE. These findings suggest exposure to BPA and BPF may be implicated as novel environmental triggers in the development of autoimmunity such as SLE. The significantly increased levels of these bisphenol analogues detected in SLE patients versus healthy controls, along with the associations between higher exposures and elevated SLE risk, which offers crucial hints for comprehending how endocrine-disrupting substances contribute to the genesis of autoimmune illnesses. Further research using robust longitudinal assessments of bisphenol analogue exposures is warranted to corroborate these epidemiological findings. Overall, this study highlights potential environmental risk factors for SLE while calling for additional investigation into the impact of bisphenol exposures on autoimmunity development.

Maternal pre-pregnancy BMI influences the associations between bisphenol and phthalate exposures and maternal weight changes and fat accumulation

BACKGROUND

Bisphenols and phthalates are two classes of endocrine-disrupting chemicals (EDCs) thought to influence weight and adiposity. Limited research has investigated their influence on maternal weight changes, and no prior work has examined maternal fat mass. We examined the associations between exposure to these chemicals during pregnancy and multiple maternal weight and fat mass outcomes.

METHODS

This study included a sample of 318 women enrolled in a Canadian prospective pregnancy cohort. Second trimester urinary concentrations of 2 bisphenols and 12 phthalate metabolites were quantified. Self-reported and measured maternal weights and measured skinfold thicknesses were used to calculate gestational weight gain, 3-months and 3- to 5-years postpartum weight retention, late pregnancy fat mass gain, total postpartum fat mass loss, and late postpartum fat mass retention. Adjusted robust regressions examined associations between chemicals and outcomes in the entire study population and sub-groups stratified by pre-pregnancy body mass index (BMI). Bayesian kernel machine regression examined chemical mixture effects.

RESULTS

Among women with underweight or normal pre-pregnancy BMIs, MBzP was negatively associated with weight retention at 3- to 5-years postpartum (B = -0.04, 95%CI: -0.07, -0.01). Among women with overweight or obese pre-pregnancy BMIs, MEHP and MMP were positively associated with weight retention at 3-months and 3- to 5-years postpartum, respectively (B's = 0.12 to 0.63, 95%CIs: 0.02, 1.07). DEHP metabolites and MCNP were positively associated with late pregnancy fat mass gain and late postpartum fat mass retention (B's = 0.04 to 0.18, 95%CIs: 0.001, 0.32). Further, the mixture of EDCs was positively associated with late pregnancy fat mass gain.

CONCLUSION

In this cohort, pre-pregnancy BMI was a key determinant of the associations between second trimester exposure to bisphenols and phthalates and maternal weight changes and fat accumulation. Investigations of underlying physiological mechanisms, windows of susceptibility, and impacts on maternal and infant health are needed.

Exposure characteristics and cumulative risk assessment of bisphenol A and its substitutes: the Taiwan environmental survey for toxicants 2013

Introduction

Ever since the use of bisphenol A (BPA) has been restricted, concerns have been raised regarding the use of its substitutes, such as bisphenol S (BPS) and bisphenol F (BPF). Meanwhile, the EU European Food Safety Authority (EFSA) issued the new tolerable daily intake (TDI) after the latest re-risk assessment for BPA, which enforced the need for cumulative risk assessment in the population. This study was conducted to identify BPA and its substitute's exposure characteristics of the general Taiwanese population and estimate the cumulative risk of bisphenol exposure.

Methods

Urine samples (N = 366 [adult, 271; minor, 95]) were collected from individuals who participated in the Taiwan Environmental Survey for Toxicants 2013. The samples were analyzed for BPA, BPS, and BPF through ultraperformance liquid chromatography-tandem mass spectrometry. Daily intake (DI) levels were calculated for each bisphenol. Hazard quotients (HQs) were calculated with the consideration of tolerable DI and a reference dose. Additionally, hazard index (HI; sum of HQs for each bisphenol) values were calculated.

Results

Our study found that the median level of BPA was significantly higher in adults (9.63 μg/g creatinine) than in minors (6.63 μg/g creatinine) (p < 0.001). The DI of BPS was higher in female (0.69 ng/kg/day) than in male (0.49 ng/kg/day); however, the DIs of BPF and BPS were higher in boys (1.15 and 0.26 ng/kg/day, respectively) than in girls (0.57 and 0.20 ng/kg/day, respectively). Most HI values exceeded 1 (99% of the participants) after EFSA re-establish the TDI of BPA.

Discussion

Our study revealed that the exposure profiles and risk of BPA and its substitute in Taiwanese varied by age and sex. Additionally, the exposure risk of BPA was deemed unacceptable in Taiwan according to new EFSA regulations, and food contamination could be the possible source of exposure. We suggest that the risk of exposure to BPA and its substitutes in most human biomonitoring studies should be reassessed based on new scientific evidence.

Perinatal bisphenol S exposure exacerbates the oxidative burden and apoptosis in neonatal ovaries by suppressing the mTOR/autophagy axis

Bisphenol S (BPS) is an emerging environmental endocrine disruptor capable of crossing the placental barrier, resulting in widespread exposure to pregnant women due to its extensive usage. However, the impact of perinatal maternal exposure to BPS on reproductive health in offspring and the underlying molecular mechanism remain underexplored. In this study, gestational ICR mice were provided with drinking water containing 3.33 mg/L BPS to mimic possible human exposure in some countries. Results demonstrated that BPS accelerated the breakdown of germ-cell cysts and the assembly of primordial follicles in neonates, leading to oocyte over-loss. Furthermore, the expression levels of folliculogenesis-related genes (Kit, Nobox, Gdf9, Sohlh2, Kitl, Bmp15, Lhx8, Figla, and Tgfb1) decreased, thus compromising oocyte quality and disrupting early folliculogenesis dynamics. BPS also disrupted other aspects of offspring reproduction, including advancing puberty onset, disrupting the estrus cycle, and impairing fertility. Further investigation found that BPS exposure inhibited the activities and expression levels of antioxidant-related enzymes in neonatal ovaries, leading to the substantial accumulation of MDA and ROS. The increased oxidative burden exacerbated the intracellular apoptotic signaling, manifested by increased expression levels of pro-apoptotic markers (Bax, Caspase 3, and Caspase 9) and decreased expression levels of anti-apoptotic marker (Bcl2). Concurrently, BPS inhibited autophagy by increasing p-mTOR/mTOR and decreasing p-ULK1/ULK1, subsequently down-regulating autophagy flux-related biomarkers (LC3b/LC3a and Beclin-1) and impeding the degradation of autophagy substrate p62. However, the imbalanced crosstalk between autophagy, apoptosis and oxidative stress homeostasis was restored after rapamycin treatment. Collectively, the findings demonstrated that BPS exposure induced reproductive disorders in offspring by perturbing the mTOR/autophagy axis, and such autophagic dysfunction exacerbated redox imbalance and promoted excessive apoptosis. These results provide novel mechanistic insights into the role of autophagy in mitigating BPS-induced intergenerational reproductive dysfunction.

Urinary concentrations of bisphenol A and its alternatives: Potential predictors of and associations with antral follicle count among women from an infertility clinic in Northern China

BACKGROUND

Experimental studies have suggested exposure to bisphenol A (BPA) and its alternatives, such as bisphenol F (BPF) and bisphenol S (BPS), may exert adverse effects on ovarian reserve, but human evidence is limited. Moreover, the potential predictors of exposure to bisphenols among women seeking infertility treatment have not been reported.

OBJECTIVE

To explore whether individual or mixture of BPA, BPF, and BPS were related to antral follicle count (AFC), and further identify the predictors of exposure to bisphenols among women seeking assisted reproductive treatment.

METHODS

A total of 111 women from a reproductive center in Shenyang, China were enrolled in this study from September 2020 to February 2021. The concentrations of urinary BPA, BPF, and BPS were measured using ultra-high-performance liquid chromatography-triple quadruple mass spectrometry (UHPLC-MS/MS). AFC was measured by two infertility physicians through transvaginal ultrasonography on the 2-5 days of a natural cycle. Demographic characteristics, dietary habits, and lifestyles were obtained by questionnaires. The associations between individual and mixture of urinary bisphenols concentrations (BPA, BPF, and BPS) and AFC were assessed by the Poisson regression models and the quantile-based g-computation (QGC) model, respectively. The potential predictors of exposure to bisphenols were identified by the multivariate linear regression models.

RESULTS

After adjusting for confounders, elevated urinary concentrations of BPA, BPF and BPS were associated with reduced AFC (β = -0.016; 95%CI: -0.025, -0.006 in BPA; β = -0.017; 95%CI: -0.029, -0.004 in BPF; β = -0.128; 95%CI: -0.197, -0.060 in BPS). A quantile increase in the bisphenols mixture was negatively associated with AFC (β = -0.101; 95%CI: -0.173, -0.030). Intake of fried food had higher urinary concentrations of BPF, BPS, and total bisphenols (∑BPs) than women who did not eat, and age was related to increased urinary BPF concentrations.

CONCLUSION

Our findings indicated that exposure to individual BPA, BPF, BPS and bisphenol mixtures were associated with impaired ovarian reserve. Furthermore, the intake of fried food, as identified in this study, could serve as an important bisphenols exposure route for reproductive-aged women.

Bisphenol chemicals in colostrum from Shanghai, China during 2006-2019: Concentration, temporal variation, and potential influence on birth parameters

Bisphenol A (BPA) and its alternatives bisphenol S (BPS) and bisphenol F (BPF) are identified as endocrine disruptors that have negative impacts on infant growth. Their temporal variations in human milk and potential effects on fetal growth are not well known. In this study, colostrum collecting at four time points between 2006 and 2019 and paired urine in 2019 from Shanghai, China, were analyzed for eight bisphenols. The total concentrations in colostrum in 2019 were up to 3.43 ng/mL, with BPA being dominant, followed by BPS and BPF. BPA levels in colostrum noticeably decreased from 2010 to 2013. Additionally, obvious percentage changes in bisphenols were observed in 2019. The BPA concentrations in paired colostrum and urine were not significantly correlated. High levels of BPA in colostrum were linked to a significant reduction in birth head circumference in 2019 (p = 0.031). BPA and BPS in colostrum might have similar negative effect on fetal growth in 2019, but these effects were generally non-significant. Further studies are needed to testify the potential impact. The hazard indexes for infants in the first week of life were below 1, suggesting no obvious health risks. However, the high contribution from BPA still warrants further attention.

Exposure to bisphenol A affects transcriptome-wide N6-methyladenine methylation in ovarian granulosa cells

Bisphenol A (BPA) is an endocrine disruptor of potential reproductive toxicities. Increasingly research elucidated that BPA exposure to the environment would change the epigenetic modifications of transcriptome, but the mechanism by which BPA affects m6A methylation in interfering with female reproductive health remains uncertain. Therefore, this study preliminarily proposed and tested the hypothesis that BPA exposure alters the m6A modification level in transcripts in female ovarian granulosa cells. After BPA was exposed to granulosa cells for 24 h, RNA methylation related regulatory genes (such as METTL3, METTL14, ALKBH5, FTO) and the global m6A levels showed significant differences. Next, we applied MERIP-seq analysis to obtain information on the genome-wide m6A modification changes and identified 1595 differentially methylated mRNA transcripts, and 50 differentially methylated lncRNA transcripts. Further joint analysis of gene common expression showed that 33 genes were hypermethylated and up-regulated, 71 were hypermethylated and down-regulated, 49 were hypomethylated and up-regulated, and 20 were hypomethylated and down-regulated. Enriched Gene Ontology (GO) and biological pathway analysis revealed that these unique genes were mainly enriched in lipid metabolism, cell proliferation, and apoptosis related pathways. Six of these genes (mRNAs IMPA1, MCOLN1, DCTN3, BRCA2, and lncRNAs MALAT1, XIST) were validated using RT-qPCR and IGV software. Through comprehensive analysis of epitranscriptome and protein-protein interaction (PPI) data, lncRNAs MALAT1 and XIST are expected to serve as new markers for BPA interfering with the female reproductive system. In brief, these data show a novel and necessary connection between the damage of BPA exposure on female ovarian granulosa cells and RNA methylation modification.

Potentiation of Adipogenesis by Reactive Oxygen Species Is a Unifying Mechanism in the Proadipogenic Properties of Bisphenol A and Its New Structural Analogues

Aims: Structural analogues of bisphenol A (BPA), including bisphenol S (BPS) and bisphenol F (BPF), are emerging environmental toxicants as their presence in the environment is rising since new regulatory restrictions were placed on BPA-containing infant products. The adipogenesis-enhancing effect of bisphenols may explain the link between human exposure and metabolic disease; however, underlying molecular pathways remain unresolved. Results: Exposure to BPS, BPF, BPA, or reactive oxygen species (ROS) generators enhanced lipid droplet formation and expression of adipogenic markers after induction of differentiation in adipose-derived progenitors isolated from mice. RNAseq analysis in BPS-exposed progenitors revealed modulation in pathways regulating adipogenesis and responses to oxidative stress. ROS were higher in bisphenol-exposed cells, while cotreatment with antioxidants attenuated adipogenesis and abolished the effect of BPS. There was a loss of mitochondrial membrane potential in BPS-exposed cells and mitochondria-derived ROS contributed to the potentiation of adipogenesis by BPS and its analogues. Male mice exposed to BPS during gestation had higher whole-body adiposity, as measured by time domain nuclear magnetic resonance, while postnatal exposure had no impact on adiposity in either sex. Innovation: These findings support existing evidence showing a role for ROS in regulating adipocyte differentiation and are the first to highlight ROS as a unifying mechanism that explains the proadipogenic properties of BPA and its structural analogues. Conclusion: ROS act as signaling molecules in the regulation of adipocyte differentiation and mediate bisphenol-induced potentiation of adipogenesis. Antioxid. Redox Signal. 40, 1-15.

Urinary concentrations of environmental phenol among pregnant women in the Japan Environment and Children's Study

Humans are exposed to various bisphenols, alkylphenols and nitrophenols through dietary intake, food packaging and container materials, indoor and outdoor air/dust. This study aimed to evaluate exposure of Japanese pregnant women to environmental phenols by measuring target compounds in urine samples. From a cohort of the Japan Environment and Children's Study, 4577 pregnant women were selected. Bisphenol A (BPA), bisphenol S (BPS), bisphenol F (BPF), bisphenol AF (BPAF), para-nitrophenol (PNP), 3-methyl-4-nitrophenol (PNMC), branched 4-nonylphenol (4-NP), linear 4-nonylphenol and 4-tert-octylphenol (4-t-OP) were analysed using a high-performance liquid chromatograph coupled to a triple-quadrupole mass spectrometer. The urinary metabolite data were combined with a questionnaire to examine the determinants of phenol exposure by machine learning. The estimated daily intake (EDI) and hazard quotient (HQ) of BPA were calculated. PNP (68.2%) and BPA (71.5%) had the highest detection frequencies, with median concentrations of 0.76 and 0.46 μg/g creatinine, respectively. PNMC, BPS, BPF and 4-NP were determined in 24.9%, 11.9%, 1.3% and 0.4% of samples, respectively, whereas BPAF (0.02%) and 4-t-OP (0.02%) were only determined in a few samples. The PNP concentrations measured in this study were comparable with those reported in previous studies, whereas the BPA concentrations were lower than those reported previously worldwide. The EDI of BPA was 0.014 μg/kg body weight/day. Compared with the tolerable daily intake set by the German Federal Institute for Risk Assessment, the median (95th percentile) HQ was 0.044 (0.2). This indicates that the observed levels of BPA exposure pose a negligible health risk to Japanese pregnant women. Determinants of bisphenol and nitrophenol exposure could not be identified by analysing the questionnaire solely, suggesting that biological measurement is necessary to assess exposure of pregnant women to bisphenols and nitrophenols. This is the first study to report environmental phenol exposure of Japanese pregnant women on a nationwide scale.

Invisible Hand behind Female Reproductive Disorders: Bisphenols, Recent Evidence and Future Perspectives

Reproductive disorders are considered a global health problem influenced by physiological, genetic, environmental, and lifestyle factors. The increased exposure to bisphenols, a chemical used in large quantities for the production of polycarbonate plastics, has raised concerns regarding health risks in humans, particularly their endocrine-disrupting effects on female reproductive health. To provide a basis for future research on environmental interference and reproductive health, we reviewed relevant studies on the exposure patterns and levels of bisphenols in environmental matrices and humans (including susceptible populations such as pregnant women and children). In addition, we focused on in vivo, in vitro, and epidemiological studies evaluating the effects of bisphenols on the female reproductive system (the uterus, ovaries, fallopian tubes, and vagina). The results indicate that bisphenols cause structural and functional damage to the female reproductive system by interfering with hormones; activating receptors; inducing oxidative stress, DNA damage, and carcinogenesis; and triggering epigenetic changes, with the damaging effects being intergenerational. Epidemiological studies support the association between bisphenols and diseases such as cancer of the female reproductive system, reproductive dysfunction, and miscarriage, which may negatively affect the establishment and maintenance of pregnancy. Altogether, this review provides a reference for assessing the adverse effects of bisphenols on female reproductive health.

Associations between the chemical exposome and pregnancy induced hypertension

Exposure to environmental chemicals has been linked to an increased risk of pregnancy-induced hypertension (PIH). This prospective cohort study examined the associations between PIH and maternal chemical exposure to four classes of chemicals (i.e., phthalates, bisphenols, perfluoroalkyl acids, non-essential metals and trace minerals). Participants included 420 pregnant women from the Alberta Pregnancy Outcomes and Nutrition (APrON) cohort who had data available on diagnosed PIH and environmental chemical exposure. Twelve phthalate metabolites, two bisphenols, eight perfluoroalkyl acids and eleven non-essential metals or trace minerals were quantified in maternal urine or blood samples collected in the second trimester of pregnancy. Associations between the urinary and blood concentrations of these chemicals and PIH were assessed using multiple logistic and LASSO regression analyses in single- and multi-chemical exposure models, respectively. Thirty-five (8.3%) participants were diagnosed with PIH. In single chemical exposure models, two phthalate metabolites, mono-methyl phthalate (MMP) and monoethyl phthalate (MEP), three perfluoroalkyl acids, perfluoroheptanoic acid (PFHpA), perfluorononanoic acid (PFNA), and perfluorodecanoic acid (PFDA), and one metal, manganese, were associated with increased odds of PIH. The metabolites of di (2-ethylhexyl) phthalate (DEHP) and the molar sum of these metabolites, as well as antimony, displayed trend associations (p < 0.10). In multi-chemical exposure models using LASSO penalized regressions and double-LASSO regressions, MEP (AOR: 1.43, 95% CI: 1.09-1.88, p = 0.009) and PFNA (AOR: 2.03, 95% CI: 1.01-4.07, p = 0.04) were selected as the chemicals most highly associated with PIH. These findings suggest that maternal levels of phthalates and perfluoroalkyl acids may be associated with the diagnosis on PIH. Future research should consider both individual and multi-chemical exposures when examining predictors of PIH and other maternal cardiometabolic health disorders, such as preeclampsia, eclampsia, HELLP syndrome, and gestational diabetes.

Methodological approaches for the assessment of bisphenol A exposure

Bisphenol A (BPA) is an endocrine disruptor used in food contact materials, by the application of polycarbonate plastics and epoxy resins. The main objective of this study is to compare the estimate of daily BPA exposure at 13 years of age and in the adult Portuguese population, using different methodological approaches, and assess the associations between this exposure and sociodemographic characteristics.

METHODOLOGY

Cross-sectional data of 13-years follow-up from a population-based birth cohort Generation XXI (GXXI) (n = 2804) and from the National Food, Nutrition and Physical Activity Survey (IAN-AF 2015-2016) (n = 3845, ≥18 years old) was used. Dietary information was collected through three food diaries for adolescents and two non-consecutive 24-hour-recalls for adults. To estimate the daily exposure to BPA, three methodological approaches were used. "Food groups attribution" merged the food consumption data with the concentration of BPA in food groups. "Regression tree model" and "random forest" combined food consumption information with urinary BPA, measured in a subsample of 24-hour urine (in adolescents n = 216, and in adults n = 82), both used to predict BPA exposure in the remaining sample. The fit-index of the methodologies was assessed through the root mean square error (RMSE), mean absolute error (MAE) and Spearman correlation coefficient (ρ). Associations between BPA exposure and sociodemographic variables were tested by linear regression models, adjusted for sex, age groups (in adults) and educational level. Tolerable Daily Intake (TDI) of 0.2 ng/kg body weight (bw), recently proposed by the European Food Safety Authority (EFSA), was used for the risk characterization of BPA exposure.

RESULTS

The "random forest" was found as the best methodology to estimate the daily BPA exposure (adolescents: RMSE = 0.989, MAE = 0.727, ρ = 0.168; adults: RMSE = 0.193, MAE = 0.147, ρ = 0.250). The median dietary BPA exposure, calculated by "food groups attribution", was 79.1 and 46.1 ng/kg bw/day for adolescents and adults, respectively, while "random forest" estimated a BPA exposure of 26.7 and 38.0 ng/kg bw/day. 99.9% of the Portuguese population presented a daily exposure above TDI. Male adolescents, females and higher educated adults, were those more exposed to BPA.

CONCLUSIONS

The estimated daily BPA exposure strongly depends on the methodological approach. Food groups attribution may overestimate the exposure while the random forest appears to be a better methodological approach to estimate BPA exposure. Nevertheless, for all methods, the Portuguese population presented an unsafe BPA exposure by largely exceeding the safe levels proposed by EFSA.

Occurrence, placental transfer, and health risks of emerging endocrine-disrupting chemicals in pregnant women

Previous studies demonstrated that many environmental chemicals can cross the human placental barrier. However, the risk regarding gestational exposure of emerging endocrine-disrupting chemicals (EDCs) is unclear. In this study, the occurrence of 24 EDCs, such as bisphenol A analogs, parabens, triclocarban, and triclosan, was investigated in serum and urine samples from Chinese pregnant women. Some metabolites were determined in matched serum-urine pairs (n = 75) to perform a comprehensive assessment of exposure. The placental transfer efficiency (PTE) of the detected chemicals was determined in matched maternal-cord serum pairs (n = 110). The mean PTEs of the chemicals showed a large variation from 43.1% to 171.0%. The potential effects of physicochemical properties, molecular structures, and biological factors on PTE were investigated using multiple linear regression models and molecular docking. We found that the PTE of methyl paraben, ethyl paraben, and propyl paraben was associated with their increasing alkyl chain lengths. Furthermore, a comprehensive exposure assessment of EDCs showed that 62.7% of pregnant women had a health index > 1, which indicted potential health risks during pregnancy. However, toxicity and the underlying mechanisms of these EDCs remain to be further studied.

Sex-specific associations between maternal phthalate exposure and neurodevelopmental outcomes in children at 2 years of age in the APrON cohort

BACKGROUND

There is inconsistent evidence regarding the sex-specific associations between prenatal phthalate exposure and children's neurodevelopment. This could be due to differences in the phthalate exposures investigated and the neurodevelopmental domains assessed.

OBJECTIVE

To evaluate the associations between prenatal phthalate exposure and sex-specific outcomes on measures of cognition, language, motor, executive function, and behaviour in children 2 years of age in the Alberta Pregnancy Outcomes and Nutrition (APrON) cohort.

METHODS

We evaluated the associations between prenatal phthalate exposure and sex-specific neurodevelopmental outcomes in children at 2 years of age using data from 448 mothers and their children (222 girls, 226 boys). Nine phthalate metabolites were measured in maternal urine collected in the second trimester of pregnancy. Children's cognitive, language, and motor outcomes were assessed using the Bayley Scales of Infant Development - Third Edition (Bayley-III). Parents completed questionnaires on children's executive function and behavior, the Behavior Rating Inventory of Executive Function- Preschool Version (BRIEF-P) and Child Behavior Checklist (CBCL), respectively. Sex-stratified robust multivariate regressions were performed.

RESULTS

Higher maternal concentrations of ΣDEHP and its metabolites were associated with lower scores on the Bayley-III Cognitive (β's from -11.8 to -0.07 95% CI's from -21.3 to -0.01), Language (β's from -11.7 to -0. 09, 95% CI's from -22.3 to -0.02) and Motor (β's from -10.9 to -0.07, 95% CI from -20.4 to -0.01) composites in boys. The patterns of association in girls were in the opposite direction on the Cognitive and Language composites; on the Motor composite they were in the same direction as boys, but of reduced strength. Higher concentrations of ΣDEHP and its metabolites were associated with higher scores (i.e., more difficulties) on all measures of executive function in girls: inhibitory self-control (B's from 0.05 to 0.11, 95% CI s from -0.01 to 0.15), flexibility (B's from 0.04 to 0.11, 95% CI s from 0.01 to 0.21) and emergent metacognition (B's from -0.01 to 0.06, 95% CIs from -0.01 to 0.20). Similar patterns of attenuated associations were seen in boys. Higher concentrations of ΣDEHP and its metabolites were associated with more Externalizing Problems in girls and boys (B's from 0.03 to 6.82, 95% CIs from -0.08 to 12.0). Two phthalates, MMP and MBP, had sex-specific adverse associations on measures of executive function and behaviour, respectively, while MEP was positively associated with boys' cognitive, language, and motor performance. Limited associations were observed between mixtures of maternal phthalates and sex-specific neurodevelopmental outcomes.

CONCLUSIONS

Maternal prenatal concentrations of DEHP phthalates were associated with sex specific difference on measures of cognition and language at 2 years of age, specifically, poorer outcomes in boys. Higher exposure to DEHP was associated with poorer motor, executive function, and behavioural outcomes in girls and boys but the strength of these associations differed by sex. Limited associations were noted between phthalate mixtures and child neurodevelopment.

Levels of Bisphenol A and its analogs in nails, saliva, and urine of children: a case control study

Introduction

A growing number of studies link the increase in overweight/obesity worldwide to exposure to certain environmental chemical pollutants that display obesogenic activity (obesogens). Since exposure to obesogens during the first stages of life has been shown to have a more intense and pronounced effect at lower doses, it is imperative to study their possible effects in childhood. The objective here was to study the association of Bisphenol A (BPA) and 11 BPA analogs in children, using three biological matrices (nails, saliva and urine), and overweight and obesity (n = 160).

Methods

In this case-control study, 59 overweight/obese children and 101 controls were included. The measuring of Bisphenols in the matrices was carried out by ultra-high performance liquid chromatography coupled with triple quadrupole tandem mass spectrometry (UHPLC-MS/MS). Logistic regression was used to study the association between overweight/obesity and Bisphenol exposure.

Results

The results suggested that BPF in nails is associated with overweight/ obesity in children (OR:4.87; p = 0.020). In saliva, however, the highest detected concentrations of BPAF presented an inverse association (OR: 0.06; p = 0.010) with overweight/obesity. No associations of statistical significance were detected between exposure to BPA or its other analogs and overweight/obesity in any of the biological matrices.

A descriptive analysis of first trimester urinary concentrations of 14 bisphenol analogues in the MIREC Canadian pregnancy cohort

BACKGROUND

Concern over the health effects of BPA, particularly for the developing fetus, has led to an increasing use of bisphenol analogues in industrial and consumer products, which may be as hormonally active as BPA. Biomonitoring data for many bisphenol analogues, especially in pregnant populations, are limited.

METHODS

We measured concentrations of 14 bisphenol analogues in 1st trimester urine samples (n = 1851) from the Maternal-Infant Research on Environmental Chemicals (MIREC) Canadian pregnancy cohort (2008-2011). We examined patterns of exposure according to sociodemographic and sampling characteristics as well as occupation and frequency of consumption of canned fish within the previous 3 months.

RESULTS

BPA was detected in 89% of participants with a specific gravity standardized geometric mean concentration of 0.990 μg/L. Biphenol 4,4' (BP 4,4'), 4,4'-dihydroxydiphenyl ether (DHDPE), and bisphenol E (BPE) were detected in >97% of participants. Bisphenol F (BPF) and bisphenol S (BPS) were detected in >60% of participants. Specific gravity standardized geometric mean concentrations of these 5 compounds ranged from 0.024 to 0.564 μg/L. Nine bisphenol analogues were detected in <9% of participants. Concentrations of BP 4,4', DHDPE, and BPE were higher in younger women and those with higher pre-pregnancy BMI, lower household income, lower education, and among smokers. We found a similar pattern of differences in BPF for age, education, and smoking status while BPS similarly differed across categories of pre-pregnancy BMI. Participants who were unemployed or working in the service industry had higher molar sum of 7 bisphenol analogues than those working in healthcare, education, or an office setting. Canned fish consumption was not related to bisphenol analogue concentrations.

CONCLUSION

BP 4,4', DHDPE, BPE, BPF, and BPS were highly detected in 1st trimester urine samples in this large pan-Canadian pregnancy cohort. This suggests widespread exposure to these analogues around 2008-2011 and warrants further investigation into associations with health outcomes.

Origin, dietary exposure, and toxicity of endocrine-disrupting food chemical contaminants: A comprehensive review

Endocrine-disrupting chemicals (EDCs) are a growing public health concern worldwide. Consumption of foodstuffs is currently thought to be one of the principal exposure routes to EDCs. However, alternative ways of human exposure are through inhalation of chemicals and dermal contact. These compounds in food products such as canned food, bottled water, dairy products, fish, meat, egg, and vegetables are a ubiquitous concern to the general population. Therefore, understanding EDCs' properties, such as origin, exposure, toxicological impact, and legal aspects are vital to control their release to the environment and food. The present paper provides an overview of the EDCs and their possible disrupting impact on the endocrine system and other organs.

Bisphenol A exposure inhibits vascular smooth muscle cell responses: Involvement of proliferation, migration, and invasion

Previous studies have associated bisphenol A (BPA) with malignant tumor formation, infertility, and atherosclerosis in vitro and in vivo. However, the precise mechanisms through which BPA affects the cardiovascular system under normal conditions remain unclear. Therefore, this study investigated the biological mechanisms through which BPA affects the responses of aortic vascular smooth muscle cells (VSMCs). BPA treatment inhibited the proliferative activity of VSMCs and induced G₂/M-phase cell cycle arrest via stimulation of the ATM-CHK2-Cdc25C-p21^WAF1-Cdc2 cascade in VSMCs. Furthermore, BPA treatment upregulated the phosphorylation of mitogen-activated protein kinase (MAPK) pathways such as ERK, JNK, and p38 MAPK in VSMCs. However, the phosphorylation level of AKT was down-regulated by BPA treatment. Additionally, the phosphorylation of ERK, JNK, and p38 MAPK was suppressed when the cells were treated with their respective inhibitors (U0126, SP600125, and SB203580). BPA suppressed MMP-9 activity by reducing the binding activity of AP-1, Sp-1, and NF-κB, thus inhibiting the invasive and migratory ability of VSMCs. These data demonstrate that BPA interferes with the proliferation, migration, and invasion capacities of VSMCs. Therefore, our findings suggest that overexposure to BPA can lead to cardiovascular damage due to dysregulated VSMC responses.

Temporal trends in bisphenol exposures and associated health risk among Japanese women living in the Kyoto area from 1993 to 2016

BACKGROUND

Bisphenols, and especially bisphenol A, are widely used as components of epoxy resins and polycarbonate. Widespread detection and potential health risks have led to bisphenol A being replaced by other alternatives, including structurally similar bisphenol analogs. Several bisphenol analogs are suspected to have similar adverse health consequences. This study examined the temporal trends in bisphenol exposure among a group of Japanese women from 1993 to 2016, and assessed the associated health risks.

METHODS

We used archived single spot urine samples of healthy Japanese women living in the Kyoto area (n = 133) collected in 1993, 2000, 2003, 2009, 2011, and 2016. We measured the concentrations of 10 bisphenols in these samples.

RESULTS

A sharp increase in the detection rates of bisphenol F was observed after 2000. There was a distinct downward trend in urinary bisphenol A concentrations and an upward trend in bisphenol E concentrations after 2009. While the hazard index for all measured bisphenols was below 1 in all subjects, bisphenol F was determined as the most important risk driver after 2000, rather than bisphenol A.

DISCUSSION

Trends of decreasing bisphenol A and increasing bisphenol E exposure especially after 2011, along with no significant change in the sum of all bisphenol analogs in urine, provide clear evidence that bisphenol A has been replaced by other bisphenols in the study population. We found no significant change in the total exposure to bisphenols during the study period. Bisphenol F might become the most important bisphenol in terms of risk, while cumulative risks due to all bisphenol exposure were deemed insignificant. Considering the accumulating evidence indicating adverse effects at lower exposure levels, further studies are warranted to assess exposure and risk from bisphenol A analogs.

Associations of bisphenol exposure with the risk of gestational diabetes mellitus: a nested case-control study in Guangxi, China

A growing number of epidemiologic studies have estimated the associations between endocrine-disrupting chemicals and gestational diabetes mellitus (GDM). However, reports on the association between bisphenol A (BPA) substitutes and GDM are limited. This investigation aimed to explore the associations of maternal serum BPA, bisphenol B (BPB), bisphenol F (BPF), bisphenol S (BPS), and tetrabromobisphenol A (TBBPA) with the risk of GDM. A nested case-control study was performed among 500 pregnant women. In conditional logistic regression models, the OR for BPS was significantly increased in the medium exposure groups (OR = 1.77; 95% CI: 1.01, 3.13) compared with the reference group, while BPA (OR: 0.38, 95%CI: 0.29, 0.50) and TBBPA (OR: 0.67, 95%CI: 0.54, 0.85) were negatively associated with the risk of GDM. In the Bayesian kernel machine regression (BKMR) analysis, the joint effect of bisphenols was positively associated with the risk of GDM. BPS showed positively relationship, while BPA and TBBPA showed negatively relationship, respectively. The quantile g-computation revealed a statistically significant and negative joint effect of the five bisphenols on the risk of GDM (OR: 0.57; 95% CI: 0.46, 0.72) with BPA (70.2%), TBBPA (21.3%), and BPB (8.5%) had positive contribution to the overall effect. These findings suggested that BPS had a positive effect on the risk of GDM, while BPA and TBBPA had negative effect on the risk of GDM. Moreover, exposure to the mixture of the five bisphenols was negatively associated with the risk of GDM.

Co-exposure to phenols and phthalates during pregnancy with the difference of body size in twins at one month old

Humans are simultaneously exposed to phenols and phthalates (PAEs). However, the mixture effect of phenols and PAEs on the body size of twins is lacking. From 2016 to 2018, we recruited 228 pregnant twins and collected up to three urine samples. A total of 8 PAE metabolites and 7 phenols were detected in urine by liquid chromatography-tandem mass spectrometry. Chemical individual and mixture effects were estimated. Multivariable linear regression results presented the percentage change in twins' growth differences at one month old with maternal PAE and phenol exposure. These chemicals were positively associated with weight differences during the entire trimester. Moreover, the quantile g-computed model showed that increased urinary concentrations of all chemicals by one quartile were associated with a 22.85% (95%CI: 11.21-35.72%), 22.60% (95%CI: 12.31-33.83%), and 24.05% (95%CI: 13.11-36.05%) larger weight difference within twins in each trimester, respectively. Increasing all PAE metabolites and phenols by one quantile across the entire trimester, weight differences increased by 26.61% (95% CI: 15.79%, 38.44%), and height differences increased by 15.84% (95%CI: 3.92%, 29.13%). Co-exposure to PAEs and phenols may primarily play a role in twins' growth.

Bisphenol A alternatives continuously contribute to the endocrine disruption in cetaceans

The bans on bisphenol A (BPA) have facilitated the widespread use of BPA alternatives and shifted environmental contamination profiles of bisphenols (BPs). However, the continued reports of toxicities of emerging BPA alternatives have raised questions about whether the shifting profiles are contributed to mitigate BPs-mediated endocrine-disruption effects (EDEs). Cetaceans are commonly used as the ideal sentinel species for monitoring marine pollutants of concern and determining potential health effects, but far less is known about BP loads and BPs-mediated EDEs in cetaceans. Here we measured the hepatic concentrations of six BPs in eight stranded cetacean species (n = 41) in the South China Sea, between 2007 and 2020. The large-bodied whales generally showed higher ∑BPs concentrations than the small-bodied dolphins. In Indo-Pacific finless porpoises (Neophocaena phocaenoides) (n = 33), BPA concentrations first increased (2007-2014) and then decreased (2014-2020), while ∑BP_Alternatives concentrations increased from 2007 to 2020. It appears that the alternatives gradually replaced BPA, probably due to the BPA-related bans in China. In order to examine the hormone disruption of BPA and its alternatives in finless porpoises, five blubber hormones (cortisol, progesterone, testosterone, triiodothyronine and tetraiodothyronine), which are proven to be validated endocrine biomarkers, were measured in 21 samples. Tetraiodothyronine, testosterone, and cortisol were significantly and positively correlated with BPA and its alternatives, suggesting that the interference of endocrine hormone homeostasis may continue to occur despite the changes of BP profiles in finless porpoises. This is the first investigation of the relationship between hormone and BP concentrations in cetaceans and represents a substantial advance in understanding BPs-mediated endocrine effects on cetaceans.

A new identity of microcystins: Environmental endocrine disruptors? An evidence-based review

Microcystins (MCs) are widely distributed cyanobacterial toxins in eutrophic waters. At present, the endocrine-disrupting effects of MCs have been extensively studied, but whether MCs can be classified as environmental endocrine disruptors (EDCs) is still unclear. This review is aimed to evaluate the rationality for MCs as to be classified as EDCs based on the available evidence. It has been identified that MCs meet eight of ten key characteristics of chemicals that can be classified as EDCs. MCs interfere with the six processes, including synthesis, release, circulation, metabolism, binding and action of natural hormones in the body. Also, they are fit two other characteristics of EDC: altering the fate of producing/responding cells and epigenetic modification. Further evidence indicates that the endocrine-disrupting effect of MCs may be an important cause of adverse health outcomes such as metabolic disorders, reproductive disorders and effects on the growth and development of offspring. Generally, MCs have endocrine-disrupting properties, suggesting that it is reasonable for them to be considered EDCs. This is of great importance in understanding and evaluating the harm done by MCs on humans.

Mechanism of action and neurotoxic effects of chronic exposure to bisphenol F in adult zebrafish

Although bisphenol F (BPF), the main replacement for bisphenol A, has been commonly used in polycarbonate production, its neurotoxicity and the underlying mechanisms remain poorly understood. To address this knowledge gap, this study aimed to assess the neurotoxicity caused by chronic exposure to BPF and to identify its underlying mechanisms. We exposed adult zebrafish chronically to BPF at environmentally relevant concentrations (0.001, 0.01, and 0.1 mg/L) for 4 weeks. The results revealed that with BPF crossing the blood-brain barrier and bioaccumulating in brain tissues, chronic exposure to BPF resulted in anxiety-like behaviors and disruptions in learning and memory function in adult zebrafish. Furthermore, BPF toxicity in the zebrafish brain involved the dysregulation of metabolic pathways for choline and kynurenine in neurotransmitter systems and for 17β-estradiol, cortisol, pregnenolone-sulfate, and Dehydroepiandrosterone (DHEA)-sulfate in neurosteroid systems. RNA-seq analysis revealed that BPF exposure affected metabolic pathways, calcium signaling pathways, neuroactive ligand-receptor interactions, tight junctions, gap junctions, and the gonadotropin-releasing hormone signaling pathway. Our results indicate that chronic exposure to BPF alters the neurochemical profile of the brain and causes neurobehavioral effects, such as anxiety and cognitive decline. Overall, the multimodal approach, including behavioral and neurochemical profiling technologies, has great potential for the comprehensive assessment of potential risks posed by environmental pollutants to human and ecosystem health.

Development and evaluation of a novel dietary bisphenol A (BPA) exposure risk tool

BACKGROUND

Exposure to endocrine disrupting chemicals such as bisphenol A (BPA) is primarily from the diet through canned foods. Characterizing dietary exposures can be conducted through biomonitoring and dietary surveys; however, these methods can be time-consuming and challenging to implement.

METHODS

We developed a novel dietary exposure risk questionnaire to evaluate BPA exposure and compared these results to 24-hr dietary recall data from participants (n = 404) of the Diet Intervention Examining The Factors Interacting with Treatment Success (DIETFITS) study, a dietary clinical trial, to validate questionnaire responses. High BPA exposure foods were identified from the dietary recalls and used to estimate BPA exposure. Linear regression models estimated the association between exposure to BPA and questionnaire responses. A composite risk score was developed to summarize questionnaire responses.

RESULTS

In questionnaire data, 65% of participants ate canned food every week. A composite exposure score validated that the dietary exposure risk questionnaire captured increasing BPA exposure. In the linear regression models, utilizing questionnaire responses vs. 24-hr dietary recall data, participants eating canned foods 1-2 times/week (vs. never) consumed 0.78 more servings (p < 0.001) of high BPA exposure foods, and those eating canned foods 3+ times/week (vs. never) consumed 0.89 more servings (p = 0.013) of high BPA exposure foods. Participants eating 3+ packaged items/day (vs. never) consumed 62.65 more total grams of high BPA exposure food (p = 0.036).

CONCLUSIONS

Dietary exposure risk questionnaires may provide an efficient alternative approach to 24-hour dietary recalls to quantify dietary BPA exposure with low participant burden.

TRIAL REGISTRATION

The trial was prospectively registered at clinicaltrials.gov as NCT01826591 on April 8, 2013.

Cytotoxic and genotoxic evaluation of bisphenol S on onion root tips by Allium cepa and comet tests

Bisphenol S (BPS) is an analog of bisphenol A, which is used as substitute of BPA in many products like airport luggage tags, baby bottles, plastics, and epoxy resins etc. Bisphenol S can cause toxic effects in different organisms, i.e., mice, rat, zebrafish, and C.elegans, etc. Bisphenol S is also known as "endocrine disruptor" due to its ability to mimic the endocrine receptors. So, the aim of this study was to evaluate the cytotoxic and genotoxic effects of bisphenol S on meristematic cells present in onion root tips through Allium cepa (A.cepa) and comet tests. Root growth inhibition was evaluated by root growth inhibition assay. Mitotic index (MI) and chromosomal aberrations (CAs) were assessed by A.cepa assay. DNA damage was evaluated by comet assay. Root growth of A.cepa was inhibited due to bisphenol S. LC50 value calculated by root growth inhibition assay for bisphenol S was (2.6±0.63, 50 μg/ml). Mitotic index was reduced, and chromosomal aberrations were observed, i.e., stickiness, polyploidy, and disturbed ana-telophase in anaphase and telophase stages of mitosis. In case of comet assay, DNA damage was increased in statistically significant manner (p ≤ 0.05). It was concluded that bisphenol S constitutes cytotoxic and genotoxic effects on A. cepa root meristematic cells. Moreover, it is suggested to explore more toxicity studies of bisphenol S at molecular level.

Exploring oxidative stress and endothelial dysfunction as a mechanism linking bisphenol S exposure to vascular disease in human umbilical vein endothelial cells and a mouse model of postnatal exposure

BACKGROUND

Structural analogues used to replace bisphenol A (BPA) since the introduction of new regulatory restrictions are considered emerging environmental toxicants and remain understudied with respect to their biological actions and health effects. Studies reveal a link between BPA exposure and vascular disease in human populations, whereas the vascular effects of BPA substitutes remain largely unknown.

OBJECTIVES

To determine the effect of BPS, a commonly used BPA substitute, on redox balance, nitric oxide (NO) availability and microvascular NO-dependent dilation.

METHODS

In human umbilical vein endothelial cells (HUVEC), production of reactive oxygen species (ROS) and NO after exposure to BPS was measured using fluorescent probes for DCFDA and DAF-FM diacetate, respectively. The contribution of endothelial NO synthase (eNOS) uncoupling to ROS generation was determined by measuring ROS in the presence or absence of an eNOS inhibitor (L-NAME) or eNOS co-factor, BH4, while the contribution of mitochondria-derived ROS was determined by treating cells with mitochondria-specific antioxidants prior to BPS exposure. Bioenergetic profiles were assessed using Seahorse extracellular flux analysis and mitochondria membrane polarization was measured with TMRE and JC-1 assays. In a mouse model of low dose BPS exposure, NO-mediated endothelial function was assessed in pressurized microvessels by inducing endothelium-dependent dilation in the presence or absence of L-NAME.

RESULTS

BPS exposure (≥25 nM) reduced NO and increased ROS production in HUVEC, the latter corrected by treating cells with L-NAME or BH4. BPS exposure led to a loss of mitochondria membrane potential but had no impact on bioenergetic parameters except for a decrease in the spare respiratory capacity. Treatment of HUVEC with mitochondria-specific antioxidants abolished the effect of BPS on NO and ROS. NO-mediated vasodilation was impaired in male mice exposed to BPS.

DISCUSSION

Exposure to BPS may promote cardiovascular disease by perturbing NO-mediated vascular homeostasis through the induction of oxidative stress.

The effects of prenatal bisphenol A exposure on brain volume of children and young mice

Bisphenol A (BPA) is a synthetic chemical used for the manufacturing of plastics, epoxy resin, and many personal care products. This ubiquitous endocrine disruptor is detectable in the urine of over 80% of North Americans. Although adverse neurodevelopmental outcomes have been observed in children with high gestational exposure to BPA, the effects of prenatal BPA on brain structure remain unclear. Here, using magnetic resonance imaging (MRI), we studied the associations of maternal BPA exposure with children's brain structure, as well as the impact of comparable BPA levels in a mouse model. Our human data showed that most maternal BPA exposure effects on brain volumes were small, with the largest effects observed in the opercular region of the inferior frontal gyrus (ρ = -0.2754), superior occipital gyrus (ρ = -0.2556), and postcentral gyrus (ρ = 0.2384). In mice, gestational exposure to an equivalent level of BPA (2.25 μg BPA/kg bw/day) induced structural alterations in brain regions including the superior olivary complex (SOC) and bed nucleus of stria terminalis (BNST) with larger effect sizes (1.07≤ Cohens d ≤ 1.53). Human (n = 87) and rodent (n = 8 each group) sample sizes, while small, are considered adequate to perform the primary endpoint analysis. Combined, these human and mouse data suggest that gestational exposure to low levels of BPA may have some impacts on the developing brain at the resolution of MRI.

Fetal exposure to phthalates and bisphenols and DNA methylation at birth: the Generation R Study

BACKGROUND

Phthalates and bisphenols are non-persistent endocrine disrupting chemicals that are ubiquitously present in our environment and may have long-lasting health effects following fetal exposure. A potential mechanism underlying these exposure-outcome relationships is differential DNA methylation. Our objective was to examine the associations of maternal phthalate and bisphenol concentrations during pregnancy with DNA methylation in cord blood using a chemical mixtures approach.

METHODS

This study was embedded in a prospective birth cohort study in the Netherlands and included 306 participants. We measured urine phthalates and bisphenols concentrations in the first, second and third trimester. Cord blood DNA methylation in their children was processed using the Illumina Infinium HumanMethylation450 BeadChip using an epigenome-wide association approach. Using quantile g-computation, we examined the association of increasing all mixture components by one quartile with cord blood DNA methylation.

RESULTS

We did not find evidence for statistically significant associations of a maternal mixture of phthalates and bisphenols during any of the trimesters of pregnancy with DNA methylation in cord blood (all p values > 4.01 * 10^-8). However, we identified one suggestive association (p value < 1.0 * 10^-6) of the first trimester maternal mixture of phthalates and bisphenols and three suggestive associations of the second trimester maternal mixture of phthalates and bisphenols with DNA methylation in cord blood.

CONCLUSIONS

Although we did not identify genome-wide significant results, we identified some suggestive associations of exposure to a maternal mixture of phthalates and bisphenols in the first and second trimester with DNA methylation in cord blood that need further exploration in larger study samples.

Effects of Oral Exposure to Low-Dose Bisphenol S on Allergic Asthma in Mice

Bisphenol S (BPS) is increasingly being used as an alternative for bisphenol A; however, its health effects remain unclear. We investigated the effects of oral exposure to low-dose BPS on allergic asthma. C3H/HeJ male mice were intratracheally administered with allergen (ovalbumin (OVA), 1 μg/animal) every 2 weeks from 6 to 11 weeks old. BPS was ingested by drinking water at doses equivalent to 0.04, 0.4, and 4 μg/kg/day. We then examined pulmonary inflammation, airway hyperresponsiveness, serum OVA-specific immunoglobulin (Ig) levels, Th2 cytokine/chemokine production, and mediastinal lymph node (MLN) cell activities. Compared with OVA alone, moderate-dose BPS (BPS-M) with OVA significantly enhanced pulmonary inflammation, airway hyperresponsiveness, and OVA-specific IgE and IgG1. Furthermore, interleukin (IL)-5, IL-13, IL-33, and CCL11/Eotaxin protein levels in the lungs increased. Conversely, these allergic responses were reduced in the high-dose BPS+OVA group. In MLN cells, BPS-M with OVA increased the total cell count and activated antigen-presenting cells including conventional dendritic cell subset (cDC2). After OVA restimulation, cell proliferation and Th2 cytokine production (IL-4, IL-5, and IL-13) in the culture supernatant also increased. Therefore, oral exposure to low-dose BPS may exacerbate allergic asthmatic responses by enhancing Th2-polarized responses and activating the MLN cells.

Variability and correlations of synthetic chemicals in urine from a New York City-based cohort of pregnant women

Fetal exposure to environmental chemicals has been associated with adverse health outcomes in children and later into adulthood. While several studies have examined correlations and variability of non-persistent chemical exposures throughout pregnancy, many do not capture more recent exposures, particularly in New York City. Our goal was to characterize exposure to phthalates, bisphenols, polycyclic aromatic hydrocarbons, and organophosphate pesticides among pregnant women residing in New York City who enrolled in the New York University Children's Health and Environment Study (NYU CHES) between 2016 and 2018. We measured urinary chemical metabolite concentrations in 671 women at early, mid, and late pregnancy (median 10.8, 20.8, and 29.3 weeks, respectively). We calculated Spearman correlation coefficients among chemical concentrations at each measurement time point. We compared changes in population-level urinary metabolites at each stage using paired Wilcoxon signed-rank tests and calculated intraclass correlation coefficients (ICCs) to quantify intra-individual variability of metabolites across pregnancy. Geometric means and ICCs were compared to nine other pregnancy cohorts that recruited women in 2011 or later as well as nationally reported levels from women of child-bearing age. Compared with existing cohorts, women in NYU CHES had higher geometric means of organophosphate pesticides (Σdiethylphosphates = 28.7 nmol/g cr, Σdimethylphosphates = 57.3 nmol/g cr, Σdialkyl phosphates = 95.9 nmol/g cr), bisphenol S (0.56 μg/g cr), and 2-naphthalene (8.98 μg/g cr). Five PAH metabolites and two phthalate metabolites increased between early to mid and early to late pregnancy at the population level. Spearman correlation coefficients for chemical metabolites were generally below 0.50. Intra-individual exposures varied over time, as indicated by low ICCs (0.22-0.88, median = 0.38). However, these ICCs were often higher than those observed in other pregnancy cohorts. These results provide a general overview of the chemical metabolites measured in NYU CHES in comparison to other contemporary pregnancy cohorts and highlight directions for future studies.

Bisphenol A in the environment and recent advances in biodegradation by fungi

Bisphenol A (BPA) is a compound used in the manufacture of a wide variety of everyday materials that, when released into the environment, causes multiple detrimental effects on humans and other organisms. The reason for this review is to provide an overview of the presence, distribution, and concentration of BPA in water, soil, sediment, and air, as well as the process of release and migration, biomagnification, and exposure mechanisms that cause various toxic effects in humans. Therefore, it is important to seek efficient and economic strategies that allow its removal from the environment and prevent it from reaching humans through food chains. Likewise, the main removal techniques are analyzed, focusing on biological treatments, particularly the most recent advances in the degradation of BPA in different environmental matrices through the use of ligninolytic fungi, non-ligninolytic fungi and yeasts, as well as the possible routes of metabolic processes that allow their biotransformation or biodegradation due to their efficient extracellular enzyme systems. This review supports the importance of the application of new biotechnological tools for the degradation of BPA.

European interlaboratory comparison investigations (ICI) and external quality assurance schemes (EQUAS) for the analysis of bisphenol A, S and F in human urine: Results from the HBM4EU project

The Human Biomonitoring for Europe initiative (HBM4EU) aims to study the exposure of citizens to chemicals and potentially associated health effects. One objective of this project has been to build a network of laboratories able to answer to the requirements of European human biomonitoring studies. Within the HBM4EU quality assurance and quality control scheme (QA/QC), a number of interlaboratory comparison investigations (ICIs) and external quality assurance schemes (EQUASs) were organized to ensure data consistency, comparability and reliability. Bisphenols are among the prioritized substance groups in HBM4EU, including bisphenol A (BPA), bisphenol S (BPS) and bisphenol F (BPF) in human urine. In four rounds of ICI/EQUAS, two target concentration levels were considered, related to around P25 and P95 of the typical exposure distribution observed in the European general population. Special attention was paid to the conjugated phase II metabolites known to be most dominant in samples of environmentally exposed individuals, through the analysis of both native samples and samples fortified with glucuronide forms. For the low level, the average percentage of satisfactory results across the four rounds was 83% for BPA, 71% for BPS and 62% for BPF. For the high level, the percentages of satisfactory results increased to 93% for BPA, 89% for BPS and 86% for BPF. 24 out of 32 participating laboratories (75%) were approved for the analyses of BPA in the HBM4EU project according to the defined criterion of Z-scores for both low and high concentration levels in at least two ICI/EQUAS rounds. For BPS and BPF, the number of qualified laboratories was 18 out of 27 (67%) and 13 out of 28 (46%), respectively. These results demonstrate a strong analytical capability for BPA and BPS in Europe, while improvements may be needed for BPF.

Effects of BPA substitutes on the prenatal and cardiovascular systems

Bisphenol A (BPA) is a ubiquitous chemical compound constantly being released into the environment, making it one of the most persistent endocrine-disrupting chemical (EDC) in nature. This EDC has already been associated with developing various pathologies, such as diabetes, obesity, and cardiovascular, renal, and behavioral complications, among others. Therefore, over the years, BPA has been replaced, gradually, by its analog compounds. However, these compounds are structurally similar to BPA, so, in recent years, questions have been raised concerning their safety for human health. Numerous investigations have been performed to determine the effects BPA substitutes may cause, particularly during pregnancy and prenatal life. On the other hand, studies investigating the association of these compounds with the development of cardiovascular diseases (CVD) have been developed. In this sense, this review summarizes the existing literature on the transgenerational transfer of BPA substitutes and the consequent effects on maternal and offspring health following prenatal exposure. In addition, these compounds' effects on the cardiovascular system and the susceptibility to develop CVD will be presented. Therefore, this review aims to highlight the need to investigate further the safety and benefits, or hazards, associated with replacing BPA with its analogs.

Within- and between-person variability of urinary phthalate metabolites and bisphenol analogues over seven days: Considerations of biomonitoring study design

Urine was used as a part of a human biomonitoring study based on the excretion kinetics of less-persistent contaminants, such as phthalates and bisphenol A (BPA). Despite the advantages of being non-invasive and easy to collect, urine can show a large variability of concentrations of phthalate metabolites and BPA within a person depending on sampling time. Therefore, it is essential to assess the variability of urinary concentrations for comprehensive sampling design in the context of exposure and risk assessments. In this study, 18 phthalate metabolites and eight BPs were measured in all spot urine (n = 401) collected from 12 participants for seven consecutive days to evaluate within- and between-person variabilities. The intraclass correlation coefficients (ICCs) for all spot urines were poor for monomethyl phthalate (ICC: 0.002) and BPA (0.121) but were moderate for monoethyl phthalate (0.514) and monobenzyl phthalate (0.462). Based on the results of di (2-ethylhexyl) phthalate (DEHP) metabolites, the half-life and differences in metabolic capability seem to affect the ICCs. Urinary mono (2-ethylhexyl) phthalate (MEHP), a primary metabolite of DEHP, was suggested as a short-term exposure marker of DEHP in our study. Creatinine- and specific gravity-adjusted concentrations of phthalate metabolites and BPs resulted in increased ICCs, implying requirements for randomly collected spot urine. Most analytes in the first morning voids (FMVs) were correlated significantly with those in the daily composites, suggesting the feasibility of FMVs to estimate the daily exposure dose. This study facilitates a more comprehensive sampling design and data interpretation strategy for human biomonitoring studies.

The Mixture of Bisphenol-A and Its Substitutes Bisphenol-S and Bisphenol-F Exerts Obesogenic Activity on Human Adipose-Derived Stem Cells

Bisphenol A (BPA) and its substitutes, bisphenol F (BPF) and S (BPS), have previously shown in vitro obesogenic activity. This study was designed to investigate their combined effect on the adipogenic differentiation of human adipose-derived stem cells (hASCs). Cells were exposed for 14 days to an equimolar mixture of bisphenols (MIX) (range 10 nM–10 µM). Oil Red staining was used to measure intracellular lipid accumulation, quantitative real-time polymerase chain reaction (qRT-PCR) to study gene expression of adipogenic markers (PPARγ, C/EBPα, LPL, and FABP4), and Western Blot to determine their corresponding proteins. The MIX promoted intracellular lipid accumulation in a dose-dependent manner with a maximal response at 10 µM. Co-incubation with pure antiestrogen (ICI 182,780) inhibited lipid accumulation, suggesting that the effect was mediated by the estrogen receptor. The MIX also significantly altered the expression of PPARγ, C/EBPα, LPL, and FABP4 markers, observing a non-monotonic (U-shaped) dose-response, with maximal gene expression at 10 nM and 10 µM and lesser expression at 1 µM. This pattern was not observed when bisphenols were tested individually. Exposure to MIX (1–10 µM) also increased all encoded proteins except for FABP4, which showed no changes. Evaluation of the combined effect of relevant chemical mixtures is needed rather than single chemical testing.

The Alberta Pregnancy Outcomes and Nutrition (APrON) longitudinal study: cohort profile and key findings from the first three years

PURPOSE

The objectives of the ongoing Canadian longitudinal cohort called the Alberta Pregnancy Outcomes and Nutrition (APrON) study are to: (1) determine the relationship between maternal nutrient intake and status before, during, after pregnancy, and (a) maternal mental health, (b) pregnancy and birth outcomes, and (c) infant/child neurodevelopment and behavior; (2) identify maternal mental health and nutrient predictors of child behaviour; and (3) establish a DNA biobank to explore genomic predictors of children's neurodevelopment and behavior. The purpose of this paper is to describe the participants, measures, and key findings on maternal and paternal mental health, maternal nutrition, and child outcomes to when children are 3 years of age.

PARTICIPANTS

Participants included mothers and their children (n=2189) and mothers' partners (usually fathers; n=1325) from whom data were collected during the period from pregnancy to when children were 3 years of age, in Alberta, Canada. More than 88% of families have been retained to take part in completed data collection at 8 years of age.

FINDINGS TO DATE

Data comprise: questionnaires completed by pregnant women/mothers and their partners on mothers', fathers' and children's health; dietary interviews; clinical assessments; linkage to hospital obstetrical records; and biological samples such as DNA. Key findings on mental health, nutrition and child outcomes are presented. APrON women who consumed more selenium and omega-3 were less likely to develop symptoms of perinatal depression. Higher prenatal consumption of choline rich foods such as eggs and milk were recommended as was vitamin D supplementation for both mothers and children to meet guidelines. Couples in which both mothers and fathers were affected by perinatal depression reported lower incomes and higher maternal prenatal depressive symptoms and lower support from fathers postnatally and their children presented with the most behavioural problems. Maternal experiences of early adversity predicted increased likelihood of perinatal depression and anxiety and children's behavioural problems.

FUTURE PLANS

The APrON cohort offers a unique opportunity to advance understanding of the developmental origins of health and disease. There is a planned follow-up to collect data at 12 years of age.

Prenatal exposure to bisphenols, immune responses in cord blood and infantile eczema: A nested prospective cohort study in China

Increasing evidence shows that human exposure to bisphenols can increase the risk of allergic disease, such as child asthma. However, the mechanism by which exposure to bisphenols causes allergic disease is unclear. In addition, the effects of exposure to bisphenols during pregnancy on infantile eczema have been poorly studied. The aim of our study was to investigate the effect of bisphenols (BPA, BPF and BPS) exposure during pregnancy on immune cells in cord blood, and on the occurrence of infantile eczema. 111 mother-child pairs with urine samples from pregnant women and cord blood were recruited from a birth cohort established in February 2019 in Shenyang, China. The levels of urinary bisphenols and Th1-, Th2-, Treg- and Th17-related genes, and cytokines in cord blood, as well as the incidence of infantile eczema at 6 and 12 months follow up were determined. Our results show that BPA, BPF and BPS were detected in 100%, 63.1% and 46.8% of the urine samples, respectively. The median concentration of urine specific gravity adjusted BPA (SG-BPA) was 7.46 ng/mL. High SG-BPA levels during pregnancy was independently associated with increased risk of infantile eczema (adjusted OR = 2.731, 95%CI: 1.064-7.012, P = 0.037). Higher levels of FOXP3 gene in cord blood had a significantly lower risk of developing eczema in infants (adjusted OR=0.430, 95%CI: 0.190-0.972, P = 0.042). However, BPS and BPF levels were not associated with infantile eczema. FOXP3 gene levels in cord blood mediated the relationship between SG-BPA levels during pregnancy and infantile eczema (indirect effect: β = 0.350 [CI:0.011,1.077]). Our findings indicate that high levels of BPA exposure during pregnancy increase the risk of infantile eczema, which may be associated with down-regulation of FOXP3 gene expression in cord blood.

Interaction of prenatal bisphenols, maternal nutrients, and toxic metal exposures on neurodevelopment of 2-year-olds in the APrON cohort

BACKGROUND

Epidemiological studies suggest that Bisphenol-A (BPA) is a developmental neurotoxicant, but the modifying effects of maternal nutrient status or neurotoxicant metal co-exposures have not been reported. Bisphenol-S (BPS) is being used as a BPA-alternative, but few epidemiological studies have evaluated its effects.

OBJECTIVES

To examine if prenatal maternal BPA or BPS exposure are associated with children's neurodevelopment at two years of age while adjusting for effect-measure modification by sex, maternal nutrients, and co-exposure to neurotoxic metals.

METHODS

Total BPA and BPS concentrations were analyzed in spot maternal urine from the second trimester; metals and maternal nutrient status were analyzed in blood. Child neurodevelopment was evaluated with the Bayley Scales of Infant Development-III (Bayley-III) at age 2 (394 maternal-child pairs) and linear regression was used to investigate associations.

RESULTS

Among nutrients and neurotoxic metals, selenium (Se) and cadmium (Cd) were the most significant predictors of Bayley-III scale scores. Higher maternal Cd was significantly correlated with poorer motor performance (p < 0.01), and higher levels of maternal Se were significantly associated with poorer performance on the cognitive, motor, and adaptive behavior scales (p < 0.05). While maternal Cd did not modify relationships between bisphenol exposures and Bayley-III scores, both maternal Se and child sex were significant effect-measure modifiers. Associations between BPA exposure and social emotional scores were negative for boys (p = 0.056) but positive for girls (p = 0.046). Higher exposure to bisphenols was associated with lower motor scores among children with lower levels of maternal Se.

CONCLUSION

Higher maternal Cd was associated with poorer motor development, but it was not an effect-measure modifier of bisphenols' effects on motor development. Maternal Se may be protective against adverse effects of bisphenols, and additional nutrient-bisphenol interaction studies examining sex-specific effects of BPA and BPS on child development are warranted.

Comparison of daily bisphenol A intake based on dietary and urinary levels in breastfeeding women

Bisphenol A (BPA) is an artificial chemical, and one of the significant external routes of daily BPA exposure is diet. Dietary BPA exposure can be calculated by urinary BPA concentration and dietary recall data. This cross-sectional study investigates exclusively breastfeeding women's BPA exposure by urinary total BPA concentration and nutritional records, including the 24 h Dietary Recall (HDR) and Food Frequency Questionnaire (FFQ). In this study, we included exclusively breastfeeding, healthy women volunteers (n = 80; 18-40 years), collected spot-morning urine samples and conducted a comprehensive face-to-face survey. Moreover, the women's urine BPA concentration was adjusted according to their urine creatinine concentrations. We assessed dietary BPA intake with the 24HDR and FFQ. Estimated daily BPA exposure according to urinary output volume and urinary creatinine concentration median values were 0.0507 and 0.06 μg/kg bw/day, respectively. Moreover, dietary BPA daily intake was found to be 0.17 and 0.95 μg/kg bw/day according to 24HDR data and FFQ data. The milk and dairy product group's and soft drinks group's contributions to the daily intake of BPA were 55.9 % and 25.92 %, respectively. The hazard ratio for BPA exposure was within limits according to references, including US EPA, Health Canada, and EFSA. This study indicates that BPA exposure, based on both total urinary BPA concentration and dietary recall data, was within the recommended daily intake level (4 μg/kg bw/day). However, further studies are required to understand the influence of seasonal, multicentre, and socioeconomic differences on BPA exposure.

Urinary Concentrations of Bisphenol Mixtures during Pregnancy and Birth Outcomes: The MAKE Study

Bisphenols are endocrine disruptors that may be associated with altered fetal growth in humans, and they have similar biological functions to mimic hormones. In addition, aggregated chemicals showed an adverse effect although individual concentration was at a low level. However, most studies between bisphenols and birth outcomes have focused on the effect of individual bisphenol. Thus, we explored the associations of urinary bisphenol mixtures with birth outcomes. We conducted a prospective birth cohort study in South Korea. One hundred eighty mother-infant pairs were recruited from 2017 to 2019. Bisphenol A (BPA), bisphenol F (BPF), and bisphenol S (BPS) in one spot urine were analyzed using ultra-performance liquid chromatography-tandem mass spectrometry. We used two statistical approaches to examine potential associations of BPA, BPF, and BPS with birth weight and gestational age: (1) multivariable linear regression; (2) Bayesian kernel machine regression (BKMR). The geometric means of BPA, BPF, and BPS were 2.1, 0.2, and 0.1 μg/L, respectively. In stratified linear analyses by each median value, a higher BPF was positively associated with birth weight (g) (β = 125.5; 95% CI: 45.0 to 205.9). Mixture analyses using BKMR suggested an inverse association between bisphenol mixtures and birth weight. Our findings suggest that in utero bisphenol exposure may influence birth weight and that such relationships may differ considering non-linearity and the combined effect.

Biologically Active Compounds in Mustard Seeds: A Toxicological Perspective

Mustard plants have been widely cultivated and used as spice, medicine and as source of edible oils. Currently, the use of the seeds of the mustard species Sinapis alba (white mustard or yellow mustard), Brassica juncea (brown mustard) and Brassica nigra (black mustard) in the food and beverage industry is immensely growing due to their nutritional and functional properties. The seeds serve as a source for a wide range of biologically active components including isothiocyanates that are responsible for the specific flavor of mustard, and tend to reveal conflicting results regarding possible health effects. Other potentially undesirable or toxic compounds, such as bisphenol F, erucic acid or allergens, may also occur in the seeds and in mustard products intended for human consumption. The aim of this article is to provide comprehensive information about potentially harmful compounds in mustard seeds and to evaluate potential health risks as an increasing use of mustard seeds is expected in the upcoming years.

Urinary bisphenol A and its alternatives among pregnant women: Predictors and risk assessment

BACKGROUND

Exposure to bisphenol A (BPA) has been associated with various adverse health outcomes. Recently, an increasing concern on its alternatives such as bisphenol S (BPS) and bisphenol F (BPF) has been aroused due to the restriction use of BPA. Few studies have identified predictors of exposure to BPA alternatives and assessed their health risks.

OBJECTIVE

The aim of this study was to identify predictors of BPA and its alternatives and to assess their health risks among pregnant women.

METHODS

We detected first morning urinary concentrations of BPA and its alternatives (BPS and BPF) among 1097 pregnant women from an established Chinese cohort. A questionnaire was conducted to obtain demographic characteristics, dietary habits, and lifestyles. We examined the predictors of creatinine-adjusted urinary BPA and its alternatives concentrations using multivariable linear regression. Risk assessment of exposure to BPA and its alternatives was calculated based on the estimated of daily intake (EDI).

RESULTS

Geometric means of creatinine-adjusted urinary BPA, BPF, and BPS were 0.92, 0.12, and 0.08 μg/g creatinine, respectively. Pregnant women from Wuhan had lower concentrations of BPA, BPF, and ∑BPs (sum of BPA, BPF, and BPS) than those from Xiaogan. Intake of fried food was related to higher concentrations of BPA, and intake of pickled food was associated with higher concentrations of BPF and ∑BPs. The maximum EDI values for exposure to BPA, BPF, BPS, and ∑BPs ranged from 5.6428 to 13.3356 nmol/kg body weight/day, which were below the tolerable daily intake (TDI) for BPA defined by the European Food Safety Authority (EFSA) (18 nmol/kg body weight/day). The maximum hazard index (HI) value was 0.7409.

CONCLUSION

Several predictors identified in this study may inform public recommendations to reduce exposure to BPA and its alternatives.

Iodide promotes bisphenol A (BPA) halogenation during chlorination: Evidence from 30 X-BPAs (X = Cl, Br, and I)

As a well known endocrine-disrupting and model chemical, bisphenol A (BPA) may pose a serious threat to human health, since it and its disinfection by-products (DBPs) have been detected in drinking water, urine, human colostrum, adipose tissue, and placenta samples. Although chlorinated BPAs (Cl-BPAs) and iodinated BPAs (I-BPAs) have been well studied, brominated BPAs (Br-BPAs), and mixed halogenated DBPs like bromo-iodo-BPAs (Br-I-BPAs), and bromo-chloro-iodo-BPAs (Cl-Br-I-BPAs) are less well understood. Notably, the role of iodide (I^-) during chlorination is not well understood, since the studies of the I-DBPs mainly focus on their genotoxicity and cytotoxicity. To understand the formation mechanisms of halogenated bisphenol A (HBPs) during chlorination with bromide (Br^-) and/or I^-, and the role of I^- during chlorination, three set of reactions were performed in the laboratory ("BPA + chlorine + Br^-", "BPA + chlorine + I^-" and "BPA + chlorine + Br^- +I^-" assigned as group A, B and C respectively). Thirty HBPs were identified and 18 of them were never reported before. I^- increases the transformation rate of BPA into HBPs as I-BPAs act as intermediate HBPs during chlorination that easily react with HClO/ClO^- and HBrO/BrO^- to form Cl-BPAs and Br-BPAs. HIO/IO^- showed higher reactivity towards BPA and HBPs than that of HBrO/BrO^- and HClO/ClO^-. The recycling of I^- was observed in the reactions of "BPA + chlorine + I^-" and "BPA + chlorine + Br^- +I^-", which may explain why I^- can induce BPA to transform into HBPs and suggests that I^- may act as a catalyst during the BPA chlorination reactions. The reaction pathways are proposed which present the reactions of BPA and HBPs with HClO/ClO^-, HBrO/BrO^-, and HIO/IO^-, as well as the recycling of I^-. This study describes the potential DBP formation and transformation mechanisms of BPA and its 16 alternatives, as well as the role of I^- on the transformation of phenol compounds during chlorination.

Factors Associated with Exposure to Dietary Bisphenols in Adolescents

Obesogenic endocrine-disrupting chemicals, such as bisphenol A (BPA) and its analogue bisphenol S (BPS), seem to play an important role in the development of obesity, although contradictory results have been reported. The aim of the present study was to conduct a gender analysis of the factors associated with exposure to dietary bisphenols in 585 Spanish adolescents. Dietary BPA and BPS exposure was assessed using a food frequency questionnaire. Foods and macronutrients accounting for more than 95% of energy intake were selected for analysis. Stepwise regression was used to estimate the foods that most contributed to dietary bisphenol exposure in the sample. Gender-related factors associated with greater dietary bisphenol exposure were evaluated using multivariate logistic regression models. Canned tuna was the main dietary source of BPA and BPS in both adolescent boys and girls. Overweight/obese girls showed a higher risk of high dietary exposure to BPA (odds ratio (OR): 3.38, 95% confidence interval (CI): 1.25-9.07) and total bisphenols (OR: 2.81, 95% CI: 1.03-7.67) in comparison with girls with a BMI lower than 25 kg/m². Present results indicate a positive association of dietary exposure to both total bisphenols and BPA with being overweight/obese in adolescent girls.

Human biomonitoring of bisphenol A along pregnancy: An exposure reconstruction of the EXHES-Spain cohort

This study was aimed at reconstructing the exposure to bisphenol (BPA) of 60 pregnant women from the EXHES-Spain cohort. A biomonitoring study was conducted by determining BPA levels in urine samples over the three trimesters of pregnancy. Moreover, the correlations between BPA levels and the role of different potential exposure sources, with special emphasis on the dietary intake, were also studied. Urine samples were subjected to dispersive liquid-liquid microextraction and the subsequent analysis via gas chromatography-mass spectrometry. BPA was detected in 76% of the urine samples. A significant decrease of urinary BPA levels was observed along pregnancy, as mean concentrations of creatinine-adjusted BPA were 4.64, 4.84 and 2.51 μg/g in the first, second and third trimester, respectively. This decrease was essentially associated with changes in the dietary habits of the pregnant women, including a lower intake of canned food and drinks. However, the potential role of other pregnancy-related biochemical or physiological factors should not be disregarded. Very interestingly, significant differences in urine BPA levels were found according to the fruit consumption pattern, as women who ate more citrus fruits showed lower BPA concentrations in urine. The reconstructed exposure to BPA was estimated in 0.072, 0.069 and 0.038 μg BPA/kg of body weight/day in the first, second and third trimesters, respectively. These values are far below the temporary tolerable daily intake (t-TDI) established by the EFSA.

Bisphenol F and bisphenol S promote lipid accumulation and adipogenesis in human adipose-derived stem cells

Bisphenol F (BPF) and bisphenol S (BPS) are increasingly used as substitutes for bisphenol A (BPA), an endocrine disrupting chemical (EDC) with obesogenic activity. We investigated the in vitro effects of BPS and BPF on the adipogenesis of human adipose-derived stem cells (hASCs) exposed to different doses (0.01, 0.1, 1, 10 and 25 μM), stopping the adipogenic process at 7 or 14 days. Intracellular lipid accumulation was quantified by the Oil Red O assay, gene expression of peroxisome proliferator-activated receptor gamma (PPARγ), CCAT/enhancer-binding protein (C/EBPα), lipoprotein-lipase (LPL) and fatty acid binding protein 4 (FABP4), by quantitative real-time polymerase chain reaction (qRT-PCR) and protein levels by Western Blot. hASCs with BPF or BPS produced a linear dose-response increase in intracellular lipid accumulation and in gene expression of the adipogenic markers, confirmed by protein levels. Co-treatment ICI 182,780 significantly inhibited BPF- but not BPS-induced lipid accumulation. Given the affinity of bisphenols for diverse nuclear receptors, their obesogenic effects may result from a combination of pathways rather than a single mechanism. Further research is warranted on the manner in which chemicals interfere with adipogenic differentiation. To our best knowledge, this report shows for the first time the obesogenic potential of BPF in hASCs.

Exposure to phthalates and bisphenol analogues among childbearing-aged women in Korea: Influencing factors and potential health risks

Phthalates and bisphenol A (BPA), widely applied in industrial and consumer products, can affect hormones associated with the human reproductive system. Because the incidence of reproductive diseases is increasing, a comprehensive exposure assessment of phthalates and bisphenol analogues (BPs) is required for childbearing-aged women. Phthalate metabolites and BPs were measured in urine samples collected from 509 childbearing-aged women (20-48 years) in Korea to investigate their current exposure status, profiles, influencing factors, and potential health risks. DEHP metabolites and BPA were the dominant compounds found, indicating that they are highly consumed in daily life. Bisphenol S (BPS), as an alternative to BPA, was detected in most urine samples. Total concentrations of phthalate metabolites and BPs ranged from 3.42 to 3570 (GM: 45.6) ng/mL and from <LOQ to 80.3 (0.91) ng/mL, respectively, which were within the ranges observed in women in previous studies. Exposure to diethyl phthalate (DEP) was significantly associated with the use of cosmetics and personal care products such as perfume, body lotion, and sunscreen. Higher ratios of urinary BPS/BPA were observed in younger and more highly educated women and in women living in urbanized regions than others. This result suggests that a shift in consumption from BPA to BPS was preferentially occurring in urbanized regions. The assessment of the cumulative risk posed by phthalates and BPs showed that they pose only a small health risk to Korean women. This study provides baseline data on exposure levels, profiles, and influencing factors for phthalates and BPs in childbearing-aged women.