Temporal trends in bisphenol A exposure in the United States from 2003-2012 and factors associated with BPA exposure: Spot samples and urine dilution complicate data interpretation

Coexposure to microplastic and Bisphenol A exhacerbates damage to human kidney proximal tubular cells

Microplastics (MPs) accumulate in tissues, including kidney tissue, while Bisphenol A (BPA) is a plasticizer of particular concern. At present, the combined effects of MPs and BPA are unexplored in human renal cells. Therefore, we exposed a proximal tubular cell line (PTECs) to polyethylene (PE)-MPs and BPA, both separately and in combination. When co-exposed, cells showed a significantly reduced cell viability (MTT test) and a pronounced pro-oxidant (MDA levels, NRF2 and NOX4 expression by Western blot) and pro-inflammatory response (IL1β, CCL/CCR2 and CCL/CCR5 mRNAs by RT-PCR), compared to those treated with a single compound. In addition, heat shock protein (HSP90), a chaperone involved in multiple cellular functions, was reduced (by Western Blot and immunocytochemistry), while aryl hydrocarbon receptor (AHR) expression, a transcription factor which binds environmental ligands, was increased (RT-PCR and immunofluorescence). Our research can contribute to the study of the nephrotoxic effects of pollutants and MPs and shed new light on the combined effects of BPA and PE-MPs.

Association of same-day urinary phenol levels and cardiac electrical alterations: analysis of the Fernald Community Cohort

BACKGROUND

Exposure to phenols has been linked in animal models and human populations to cardiac function alterations and cardiovascular diseases, although their effects on cardiac electrical properties in humans remains to be established. This study aimed to identify changes in electrocardiographic (ECG) parameters associated with environmental phenol exposure in adults of a midwestern large cohort known as the Fernald Community Cohort (FCC).

METHODS

During the day of the first comprehensive medical examination, urine samples were obtained, and electrocardiograms were recorded. Cross-sectional linear regression analyses were performed.

RESULTS

Bisphenol A (BPA) and bisphenol F (BPF) were both associated with a longer PR interval, an indication of delayed atrial-to-ventricle conduction, in females (p < 0.05) but not males. BPA combined with BPF was associated with an increase QRS duration, an indication of delayed ventricular activation, in females (P < 0.05) but not males. Higher triclocarban (TCC) level was associated with longer QTc interval, an indication of delayed ventricular repolarization, in males (P < 0.01) but not females. Body mass index (BMI) was associated with a significant increase in PR and QTc intervals and ventricular rate in females and in ventricular rate in males. In females, the combined effect of being in the top tertile for both BPA urinary concentration and BMI was an estimate of a 10% increase in PR interval. No associations were found with the other phenols.

CONCLUSION

Higher exposure to some phenols was associated with alterations of cardiac electrical properties in a sex specific manner in the Fernald cohort. Our population-based findings correlate directly with clinically relevant parameters that are associated with known pathophysiologic cardiac conditions in humans.

Association of same-day urinary phenol levels and cardiac electrical alterations: analysis of the Fernald Community Cohort

Background

Exposure to phenols has been linked in animal models and human populations to cardiac function alterations and cardiovascular diseases, although their effects on cardiac electrical properties in humans remains to be established. This study aimed to identify changes in electrocardiographic (ECG) parameters associated with environmental phenol exposure in adults of a midwestern large cohort known as the Fernald Community Cohort (FCC).

Methods

During the day of the first comprehensive medical examination, urine samples were obtained, and electrocardiograms were recorded. Cross-sectional linear regression analyses were performed.

Results

Bisphenol A (BPA) and bisphenol F (BPF) were both associated with a longer PR interval, an indication of delayed atrial-to-ventricle conduction, in females (p < 0.05) but not males. BPA combined with BPF was associated with an increase QRS duration, an indication of delayed ventricular activation, in females (P < 0.05) but not males. Higher triclocarban (TCC) level was associated with longer QTc interval, an indication of delayed ventricular repolarization, in males (P < 0.01) but not females. Body mass index (BMI) was associated with a significant increase in PR and QTc intervals and ventricular rate in females and in ventricular rate in males. In females, the combined effect of being in the top tertile for both BPA urinary concentration and BMI was an estimate of a 10% increase in PR interval. No associations were found with the other phenols.

Conclusion

Higher exposure to some phenols was associated with alterations of cardiac electrical properties in a sex specific manner in the Fernald cohort. Our population-based findings correlate directly with clinically relevant parameters that are associated with known pathophysiologic cardiac conditions in humans.

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.

The triple exposure nexus of microplastic particles, plastic-associated chemicals, and environmental pollutants from a human health perspective

The presence of microplastics (MPs) is increasing at a dramatic rate globally, posing risks for exposure and subsequent potential adverse effects on human health. Apart from being physical objects, MP particles contain thousands of plastic-associated chemicals (i.e., monomers, chemical additives, and non-intentionally added substances) captured within the polymer matrix. These chemicals are often migrating from MPs and can be found in various environmental matrices and human food chains; increasing the risks for exposure and health effects. In addition to the physical and chemical attributes of MPs, plastic surfaces effectively bind exogenous chemicals, including environmental pollutants (e.g., heavy metals, persistent organic pollutants). Therefore, MPs can act as vectors of environmental pollution across air, drinking water, and food, further amplifying health risks posed by MP exposure. Critically, fragmentation of plastics in the environment increases the risk for interactions with cells, increases the presence of available surfaces to leach plastic-associated chemicals, and adsorb and transfer environmental pollutants. Hence, this review proposes the so-called triple exposure nexus approach to comprehensively map existing knowledge on interconnected health effects of MP particles, plastic-associated chemicals, and environmental pollutants. Based on the available data, there is a large knowledge gap in regard to the interactions and cumulative health effects of the triple exposure nexus. Each component of the triple nexus is known to induce genotoxicity, inflammation, and endocrine disruption, but knowledge about long-term and inter-individual health effects is lacking. Furthermore, MPs are not readily excreted from organisms after ingestion and they have been found accumulated in human blood, cardiac tissue, placenta, etc. Even though the number of studies on MPs-associated health impacts is increasing rapidly, this review underscores that there is a pressing necessity to achieve an integrated assessment of MPs' effects on human health in order to address existing and future knowledge gaps.

Identifying critical windows of prenatal phenol, paraben, and pesticide exposure and child neurodevelopment: Findings from a prospective cohort study

BACKGROUND

This study aimed to investigate how exposure to a mixture of endocrine disrupting chemicals (EDCs) during two points in pregnancy affects early childhood neurodevelopment.

METHODS

We analyzed publicly-available data from a high-risk cohort of mothers and their children (2007-2014) that measured six EDCs including methyl-, ethyl- and propyl parabens (MEPB, ETPB, PRPB), Bisphenol-A (BPA), 3,5,6-trichloro-2-pyridinol (TCPy), 3-phenoxybenzoic acid (3-PBA) in prenatal urine samples during the second and third trimesters. Neurodevelopmental scores were assessed using Mullen Scales of Early Learning (MSEL) at age 3. We used mean field variational Bayes for lagged kernel machine regression (MFVB-LKMR) to investigate the association between trimester-specific co-exposure to the six EDCs and MSEL scores at age 3, stratified by sex.

RESULTS

The analysis included 130 children. For females, the relationship between BPA and 3PBA with MSEL score varied between the two trimesters. In the second trimester, effect estimates for BPA were null but inversely correlated with MSEL score in the third trimester. 3PBA had a negative relationship with MSEL in the second trimester and positive correlation in the third trimester. For males, effect estimates for all EDCs were in opposing directions across trimesters. MFVB-LKMR analysis identified significant two-way interaction between EDCs for MSEL scores in both trimesters. For example, in females, the MSEL scores associated with increased exposure to TCPy were 1.75 units (95%credible interval -0.04, -3.47) lower in the 2nd trimester and 4.61 (95%CI -3.39, -5.84) lower in the third trimester when PRPB was fixed at the 75th percentile compared to when PRPB was fixed at the 25th percentile.

CONCLUSION

Our study provides evidence that timing of EDC exposure within the prenatal period may impact neurodevelopmental outcomes in children. More of these varying effects were identified among females. Future research is needed to explore EDC mixtures and the timing of exposure during pregnancy to enhance our understanding of how these chemicals impact child health.

Effects of Behavioral, Clinical, and Policy Interventions in Reducing Human Exposure to Bisphenols and Phthalates: A Scoping Review

BACKGROUND

There is growing interest in evidence-based interventions, programs, and policies to mitigate exposures to bisphenols and phthalates and in using implementation science frameworks to evaluate hypotheses regarding the importance of specific approaches to individual or household behavior change or institutions adopting interventions.

OBJECTIVES

This scoping review aimed to identify, categorize, and summarize the effects of behavioral, clinical, and policy interventions focused on exposure to the most widely used and studied bisphenols [bisphenol A (BPA), bisphenol S (BPS), and bisphenol F (BPF)] and phthalates with an implementation science lens.

METHODS

A comprehensive search of all individual behavior, clinical, and policy interventions to reduce exposure to bisphenols and phthalates was conducted using PubMed, Web of Science, Cumulative Index to Nursing and Allied Health Literature (CINAHL), and Google Scholar. We included studies published between January 2000 and November 2022. Two reviewers screened references in CADIMA, then extracted data (population characteristics, intervention design, chemicals assessed, and outcomes) for studies meeting inclusion criteria for the present review.

RESULTS

A total of 58 interventions met the inclusion criteria. We classified interventions as dietary (n = 27 ), clinical (n = 13 ), policy (n = 14 ), and those falling outside of these three categories as "other" (n = 4 ). Most interventions (81%, 47/58) demonstrated a decrease in exposure to bisphenols and/or phthalates, with policy level interventions having the largest magnitude of effect.

DISCUSSION

Studies evaluating policy interventions that targeted the reduction of phthalates and BPA in goods and packaging showed widespread, long-term impact on decreasing exposure to bisphenols and phthalates. Clinical interventions removing bisphenol and phthalate materials from medical devices and equipment showed overall reductions in exposure biomarkers. Dietary interventions tended to lower exposure with the greatest magnitude of effect in trials where fresh foods were provided to participants. The lower exposure reductions observed in pragmatic nutrition education trials and the lack of diversity (sociodemographic backgrounds) present limitations for generalizability to all populations. https://doi.org/10.1289/EHP11760.

BPA and low-Se exacerbate apoptosis and mitophagy in chicken pancreatic cells by regulating the PTEN/PI3K/AKT/mTOR pathway

INTRODUCTION

Bisphenol A (BPA) is a widespread environmental pollutant which has serious toxic effects on organisms. One of the crucial trace elements is selenium (Se), whose shortage can harm biological tissues and enhance the toxicity of contaminants, in which apoptosis and autophagy are core events.

OBJECTIVES

An in vivo model was established to investigate the effects of BPA and low-Se on chicken pancreatic tissue, and identify the possible potential molecular mechanism.

METHODS

A total of 80 1-day-old broiler chickens (Xinghua Chicken Farm, Harbin, China) were stochastically divided into 4 groups (n = 20/group): Control group, BPA group, low-Se group, and low-Se + BPA group. Pancreatic tissue was collected at day 42 to detect changes in markers.

RESULTS

First, the data showed that BPA and low-Se exposure gave rose to structural abnormalities in pancreatic tissue, oxidative stress, mitochondrial dysfunction and homeostasis imbalance, apoptosis and mitophagy. In addition, the co-exposure of BPA and low-Se caused the most serious damage to pancreatic tissue. In terms of mechanism, it was found that apoptosis and mitophagy induced by BPA and low-Se were related to the activation of PTEN/PI3K/AKT/mTOR pathway.

CONCLUSION

In summary, the study found that BPA and low-Se exacerbated mitochondria damage, apoptosis and mitophagy by regulating the PTEN/PI3K/AKT/mTOR pathway.

Bisphenol S, bisphenol F, bisphenol a exposure and body composition in US adults

Bisphenol S (BPS) and bisphenol F (BPF) are increasingly used to replace bisphenol A (BPA), an endocrine-disrupting chemical with putative obesogenic properties; whether and how BPS and BPF affect adiposity in humans remains to be determined. Therefore, we examined the association of BPA, BPS， and BPF with body composition among US adults. We included 1787 participants aged 20-59 years old in the National Health and Nutrition Examination Survey 2013-2016 who had information on urinary BPA, BPS, and BPF concentrations, and body composition measured using dual-energy x-ray absorptiometry. After full adjustment for potential confounders in linear regression models, BPA was significantly associated with the % body fat of the whole body, arm, and leg, with the β (95% CI) for the highest quartile vs. the lowest quartile of 1.34 (95%CI [0.11, 2.58], P = 0.03), 1.60 (95%CI [0.20, 3.00], P = 0.03), and 1.63 (95%CI [0.24, 3.02], P = 0.02), respectively. No association between BPA and lean mass was found. For BPS, significant associations were found for % body fat of the whole body (β [95% CI] = 1.42 [0.49, 2.36], P = 0.004), trunk (β[95% CI] = 1.92 [0.86, 2.97], P = 0.001), and arm (β [95% CI] = 1.60 [0.49, 2.70], P = 0.01), as well as lean mass of the whole body (β [95% CI] = 2610.6 [1324.3, 3896.8], P < 0.001), trunk (β [95% CI] = 1467.0 [745.3, 2188.7], P < 0.001), arm (β [95% CI] = 113.4 [10.3, 216.5], P = 0.03), and leg (β [95% CI] = 431.5 [219.6, 643.4], P < 0.001), comparing the third quartile vs. the lowest quartile. No significant association was observed between BPF and % body fat and lean mass. Results suggest that higher BPA levels were significantly associated with greater % body fat of the whole body and limbs, and there was suggestive evidence that BPS levels were associated with both % body fat and lean mass of the whole body and body parts in a nonmonotonic relationship.

Temporal trends in urinary concentrations of phenols, phthalate metabolites and phthalate replacements between 2000 and 2017 in Boston, MA

Endocrine disrupting chemicals (EDCs) can adversely affect human health and are ubiquitously found in everyday products. We examined temporal trends in urinary concentrations of EDCs and their replacements. Urinary concentrations of 11 environmental phenols, 15 phthalate metabolites, phthalate replacements such as two di(isononyl)cyclohexane-1,2-dicarboxylate (DINCH) metabolites, and triclocarban were quantified using isotope-dilution tandem mass spectrometry. This ecological study included 996 male and 819 female patients who were predominantly White/Caucasian (83 %) with an average age of 35 years and a BMI of 25.5 kg/m2 seeking fertility treatment in Boston, MA, USA. Patients provided a total of 6483 urine samples (median = 2, range = 1-30 samples per patient) between 2000 and 2017. Over the study period, we observed significant decreases (% per year) in urinary concentrations of traditional phenols, parabens, and phthalates such as bisphenol A (β: -6.3, 95 % CI: -7.2, -5.4), benzophenone-3 (β: -6.5, 95 % CI: -1.1, -18.9), parabens ((β range:-5.4 to -14.2), triclosan (β: -18.8, 95 % CI: -24, -13.6), dichlorophenols (2.4-dichlorophenol β: -6.6, 95 % CI: -8.8, -4.3); 2,5-dichlorophenol β: -13.6, 95 % CI: -17, -10.3), di(2-ethylhexyl) phthalate metabolites (β range: -11.9 to -22.0), and other phthalate metabolites including mono-ethyl, mono-n-butyl, and mono-methyl phthalate (β range: -0.3 to -11.5). In contrast, we found significant increases in urinary concentrations of environmental phenol replacements including bisphenol S (β: 3.9, 95 % CI: 2.7, 7.6) and bisphenol F (β: 6, 95 % CI: 1.8, 10.3), DINCH metabolites (cyclohexane-1,2-dicarboxylic acid monohydroxy isononyl ester [MHiNCH] β: 20, 95 % CI: 17.8, 22.2; monocarboxyisooctyl phthalate [MCOCH] β: 16.2, 95 % CI: 14, 18.4), and newer phthalate replacements such as mono-3-carboxypropyl phthalate, monobenzyl phthalate, mono-2-ethyl-5-carboxypentyl phthalate and di-isobutyl phthalate metabolites (β range = 5.3 to 45.1), over time. Urinary MHBP concentrations remained stable over the study period. While the majority of biomarkers measured declined over time, concentrations of several increased, particularly replacement chemicals that are studied.

Worldwide risk assessment of phthalates and bisphenol A in humans: The need for updating guidelines

Phthalates and bisphenol A (BPA) are compounds widely used as raw materials in the production of plastics, making them ubiquitous in our daily lives. This results in widespread human exposure and human health hazards. Although efforts have been conducted to evaluate the risk of these compounds in diverse regions around the world, data scattering may mask important trends that could be useful for updating current guidelines and regulations. This study offers a comprehensive global assessment of human exposure levels to these chemicals, considering dietary and nondietary ingestion, and evaluates the associated risk. Overall, the exposure daily intake (EDI) values of phthalates and BPA reported worldwide ranged from 1.11 × 10-7 to 3 700 µg kg bw-1 d-1 and from 3.00 × 10-5 to 6.56 µg kg bw-1 d-1, respectively. Nevertheless, the dose-additive effect of phthalates has been shown to increase the EDI up to 5 100 µg kg bw-1 d-1, representing a high risk in terms of noncarcinogenic (HQ) and carcinogenic (CR) effects. The worldwide HQ values of phthalates and BPA ranged from 2.25 × 10-7 to 3.66 and from 2.74 × 10-7 to 9.72 × 10-2, respectively. Meanwhile, a significant number of studies exhibit high CR values for benzyl butyl phthalate (BBP) and di(2-ethylhexyl) phthalate (DEHP). Moreover, DEHP has shown the highest maximum mean CR values for humans in numerous studies, up to 179-fold higher than BBP. Despite mounting evidence of the harmful effects of these chemicals at low-dose exposure on animals and humans, most regulations have not been updated. Thus, this article emphasizes the need for updating guidelines and public policies considering compelling evidence for the adverse effects of low-dose exposure, and it cautions against the use of alternative plasticizers as substitutes for phthalates and BPA because of the significant gaps in their safety.

Underestimation of glyphosate intake by the methods currently used by regulatory agencies

The acceptable daily intake (ADI) is an estimate of the amount of a substance in food or beverages that can be consumed daily over a lifetime without presenting an appreciable risk to health. To assess the risk of ingesting glyphosate, regulatory agencies compare glyphosate daily intake to ADI. Based on published data on urine glyphosate levels measured according to known quantities of ingested glyphosate, our objectives were to test the robustness of the mathematical model currently used to calculate glyphosate daily intake, and to propose alternative models based on urinary excretion kinetics. Our results support that the quantity of ingested glyphosate is systematically underestimated by the model currently used by regulatory agencies, whereas the other models evaluated showed better estimations, with differences according to gender. Our results also show a great variability between individuals, leading to some uncertainties notably with regards to the ADI, and further support that glyphosate excretion varies significantly among individuals who follow a similar dosing regimen. In conclusion, our study highlights the lack of reliability of assessment processes carried out by regulatory agencies for glyphosate in particular, and pesticides in general, and questions the relevance of such processes supposed to safeguard human health and the environment.

In vivo effects of low dose prenatal bisphenol A exposure on adiposity in male and female ICR offspring

BACKGROUND

Bisphenol A (BPA) is known to exhibit endocrine disrupting activities and is associated with adiposity. We examined the obesogenic effect of prenatal BPA exposure in the present study.

METHODS

Pregnant ICR mice were exposed to vehicle or BPA via the drinking water at a dose of 0.5 μg/kg·d throughout the gestation. Obesity-related indexes were investigated in the 12-wk-old offspring. Primary mouse embryonic fibroblasts (MEFs) collected from treated embryos were used to test effects of BPA on adipocyte differentiation.

RESULTS

Offspring presented a significantly higher rate of weight gain than the control, with impaired insulin sensitivity and increased adipocyte size. Differentiation of MEFs from BPA-treated mice showed a higher propensity for the adipocyte commitment as well as up-regulation of genes enriched in lipid biosynthesis. TGF-β signaling pathway was found to modulate obesogenic effect of BPA in MEF model, but estrogen signaling pathway had no effect.

CONCLUSIONS

The present study provides strong evidence of the association between prenatal exposure to low dose of BPA and a significant increase in body weight in the offspring mice with a critical role played by TGF-β signaling pathway. The potential interactions modulating the binding of BPA and TGF-β that activate its obesogenic effects need to be examined.

Association between Bisphenol A exposure and body composition parameters in children

Background

Although there is evidence linking Bisphenol A (BPA) exposure to obesity, research examining its relationship with body composition parameters in young children is limited.

Methods

A cross-sectional investigation was conducted on 200 preschool children aged between 4 and 6 years in Guangzhou, China. BPA exposure was assessed through urine samples using ultra-high performance liquid chromatography- tandem mass spectrometry, and body composition parameters were measured through bioelectrical impedance analysis (InBody770).

Results

The median urinary BPA concentration was 0.556 μg/L (IQR: 0.301 - 1.031 μg/L) and creatinine-adjusted BPA concentration was 0.930 μg/g (IQR: 0.551 - 1.586 μg/g). BPA levels were significantly associated with body mass index (β= 1.15; 95%CI: 0.47, 1.83), body fat mass (β= 1.14; 95%CI: 0.39, 1.89), fat free mass (β= 0.92; 95%CI: 0.26, 1.58), and percent body fat (β= 3.44; 95%CI: 1.17, 5.71) after adjusting for potential confounding factors. Similarly, adjusted models with log₁₀-transformed creatinine-adjusted BPA concentrations as a continuous variable showed similar trends. Positive linear associations were observed between quartiles of BPA concentrations and body composition parameters, with the highest coefficients in the fourth quartile.

Conclusion

Our study provides further evidence of positive correlations between BPA exposure and body composition parameters in children aged 4 to 6 years. These findings highlight the potential health risks associated with obesity-related body composition parameters in young children. Further investigations are needed to confirm this association and explore the underlying mechanisms.

How to use human biomonitoring in chemical risk assessment: Methodological aspects, recommendations, and lessons learned from HBM4EU

One of the aims of the European Human Biomonitoring Initiative, HBM4EU, was to provide examples of and good practices for the effective use of human biomonitoring (HBM) data in human health risk assessment (RA). The need for such information is pressing, as previous research has indicated that regulatory risk assessors generally lack knowledge and experience of the use of HBM data in RA. By recognising this gap in expertise, as well as the added value of incorporating HBM data into RA, this paper aims to support the integration of HBM into regulatory RA. Based on the work of the HBM4EU, we provide examples of different approaches to including HBM in RA and in estimations of the environmental burden of disease (EBoD), the benefits and pitfalls involved, information on the important methodological aspects to consider, and recommendations on how to overcome obstacles. The examples are derived from RAs or EBoD estimations made under the HBM4EU for the following HBM4EU priority substances: acrylamide, o-toluidine of the aniline family, aprotic solvents, arsenic, bisphenols, cadmium, diisocyanates, flame retardants, hexavalent chromium [Cr(VI)], lead, mercury, mixture of per-/poly-fluorinated compounds, mixture of pesticides, mixture of phthalates, mycotoxins, polycyclic aromatic hydrocarbons (PAHs), and the UV-filter benzophenone-3. Although the RA and EBoD work presented here is not intended to have direct regulatory implications, the results can be useful for raising awareness of possibly needed policy actions, as newly generated HBM data from HBM4EU on the current exposure of the EU population has been used in many RAs and EBoD estimations.

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.

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.

Impact of a bisphenol A, F, and S mixture and maternal care on the brain transcriptome of rat dams and pups

Products containing BPA structural analog replacements have increased in response to growing public concern over adverse effects of BPA. Although humans are regularly exposed to a mixture of bisphenols, few studies have examined effects of prenatal exposure to BPA alternatives or bisphenol mixtures. In the present study, we investigate the effect of exposure to an environmentally-relevant, low-dose (150 ug/kg body weight per day) mixture of BPA, BPS, and BPF during gestation on the brain transcriptome in Long-Evans pups and dams using Tag RNA-sequencing. We also examined the association between dam licking and grooming, which also has enduring effects on pup neural development, and the transcriptomes. Associations between licking and grooming and the transcriptome were region-specific, with the hypothalamus having the greatest number of differentially expressed genes associated with licking and grooming in both dams and pups. Prenatal bisphenol exposure also had region-specific effects on gene expression and pup gene expression was affected more robustly than dam gene expression. In dams, the prelimbic cortex had the greatest number of differentially expressed genes associated with prenatal bisphenol exposure. Prenatal bisphenol exposure changed the expression of over 2000 genes in pups, with the majority being from the pup amygdala. We used Gene Set Enrichment Analysis (GSEA) to asses enrichment of gene ontology biological processes for each region. Top GSEA terms were diverse and varied by brain region and included processes known to have strong associations with steroid hormone regulation, cilium-related terms, metabolic/biosynthetic process terms, and immune terms. Finally, hypothesis-driven analysis of genes related to estrogen response, parental behavior, and epigenetic regulation of gene expression revealed region-specific expression associated with licking and grooming and bisphenol exposure that were distinct in dams and pups. These data highlight the effects of bisphenols on multiple physiological process that are highly dependent on timing of exposure (prenatal vs. adulthood) and brain region, and reiterate the contributions of multiple environmental and experiential factors in shaping the brain.

Benzophenone-3 and antinuclear antibodies in U.S. adolescents and adults ages 12-39 years

Background

Between 1988 and 2012, prevalence of antinuclear antibodies (ANA) increased in the U.S., especially in adolescents and non-Hispanic Whites. Female predominance of ANA suggests a role for hormonal factors, including xenobiotic exposures that may disrupt endocrine signaling. Benzophenone-3 (BP-3) is one such chemical with increasing exposure through sunscreen use. We investigated whether urinary BP-3 levels were related to ANA in adolescents and young adults.

Methods

In a sample of 1,785 individuals ages 12-39 years in the National Health and Nutrition Examination Survey (NHANES; 2003-4, 2011-12), we examined cross-sectional associations of ANA (N=192; 3+ or 4+ at the 1:80 dilution, measured by HEp-2 immunofluorescence) with urinary BP-3, and other phenols bisphenol-A, triclosan, and parabens. Adjusted prevalence odds ratios (POR) were calculated in season-stratified models [winter (November-April) and summer (May-October)], given differences in sunscreen use and BP-3 concentrations.

Results

BP-3 concentrations (detected in >98.5% of individuals) did not differ by ANA positivity in the summer (geometric mean, GM 30.6 ng/ml ANA-positive vs. 35.3 ANA-negative; GM ratio 1.15), but in winter were higher among ANA-positives (50.2 vs. 20.1 ANA-negative; GM ratio 2.50). ANA was associated with log₁₀BP-3 in winter (POR 1.57; 95%CI 1.07-2.30 per unit increase) but not summer (0.94; 0.61, 1.44; interaction p=0.09). Triclosan, parabens, and bisphenol-A levels were unrelated to ANA overall or by season (ORs 0.64 to 1.33).

Conclusions

The association of urinary BP-3 with ANA in the winter may reflect different exposure patterns or unmeasured confounders. Findings warrant replication in prospective studies and including past and year-round exposures.

Cross-Sectional Association of Urinary Bisphenol A and Vaccine-Induced Immunity against Hepatitis B Virus: Data from the 2003–2014 National Health and Nutrition Examination Survey

Hepatitis B virus (HBV) infection poses a serious health burden; bisphenol A (BPA), a commonly used plasticizer for consumer products, is a potential immune disruptor. However, epidemiologic studies revealing the association between BPA exposure and immunity are limited. This study investigates the association between environmental BPA exposure and immune response following HBV vaccination in a nationally representative sample population. Using National Health and Nutrition Examination Survey data from six cycles, we analyzed the data of 6134 participants, classified as susceptible to HBV infection (n = 3086) or as having vaccine-induced immunity (n = 3048). Associations between BPA level and HBV susceptibility were assessed using multivariable logistic regression and expressed as odds ratios (ORs) of the pooled data and data for each cycle. There was a significant association in the pooled data after adjusting for potential confounders (adjusted OR (aOR): 1.14, 95% confidence interval (CI): 1.05–1.23). However, the associations between BPA concentration and HBV susceptibility were inconsistent across the survey cycles and tended to decrease in more recent cycles. Although this study preliminarily suggests that BPA attenuates the immune response to hepatitis B vaccination, further prospective studies are warranted to elucidate the discrepancies observed.

Variability of Urinary Concentrations of Phenols, Parabens, and Triclocarban during Pregnancy in First Morning Voids and Pooled Samples

Urinary concentrations of phenols, parabens, and triclocarban have been extensively used as biomarkers of exposure. However, because these compounds are quickly metabolized and excreted in urine, characterizing participants' long-term average exposure from a few spot samples is challenging. To examine the variability of urinary concentrations of these compounds during pregnancy, we quantified four phenols, four parabens, and triclocarban in 357 first morning voids (FMVs) and 203 pooled samples collected during the second and third trimesters of 173 pregnancies. We computed intraclass correlation coefficients (ICCs) by the sample type (FMV and pool) across two trimesters and by the number of composite samples in pools, ranging from 2 to 4, within the same trimester. Among the three compounds detected in more than 50% of the samples, the ICCs across two trimesters were higher in pools (0.29-0.68) than in FMVs (0.17-0.52) and the highest ICC within the same trimester was observed when pooling either two or three composites. Methyl paraben and propyl paraben primarily exposed via cosmetic use had approximately 2-3 times higher ICCs than bisphenol A primarily exposed via diet. Our findings support that within-subject pooling of biospecimens can increase the reproducibility of pregnant women's exposure to these compounds and thus could potentially minimize exposure misclassification.

Early developmental exposure to bisphenol A and bisphenol S disrupts socio-cognitive function, isotocin equilibrium, and excitation-inhibition balance in developing zebrafish

Dysregulation of the oxytocinergic system and excitation/inhibition (E/I) balance in synaptic transmission and neural circuits are common hallmarks of various neurodevelopmental disorders. Several experimental and epidemiological studies have shown that perinatal exposure to endocrine-disrupting chemicals bisphenol A (BPA) and bisphenol S (BPS) may contribute to a range of childhood neurodevelopmental disorders. However, the effects of BPA and BPS on social-cognitive development and the associated mechanisms remain largely unknown. In this study, we explored the impacts of early developmental exposure (2hpf-5dpf) to environmentally relevant concentrations of BPA, and its analog BPS (0.001, 0.01, and 0.1 μM), on anxiety, social behaviors, and memory performance in 21 dpf zebrafish larvae. Our results revealed that early-life exposure to low concentrations of BPA and BPS elevated anxiety-like behavior, while fish exposed to higher concentrations of these chemicals displayed social deficits and impaired object recognition memory. Additionally, we found that co-exposure with an aromatase inhibitor antagonized BPA- and BPS-induced effects on anxiety levels and social behaviors, while the co-exposure to an estrogen receptor antagonist restored recognition memory in zebrafish larvae. These results indicate that BPA and BPS may affect social-cognitive function through distinct mechanisms. On the other hand, exposure to low BPA/BPS concentrations increased both the mRNA and protein levels of isotocin (zebrafish oxytocin) in the zebrafish brain, whereas a reduction in its mRNA level was observed at higher concentrations. Further, alterations in the transcript abundance of chloride transporters, and molecular markers of gamma-aminobutyric acid (GABA) and glutamatergic systems, were observed in the zebrafish brain, suggesting possible E/I imbalance following BPA or BPS exposure. Collectively, the results of this study demonstrate that early-life exposure to low concentrations of the environmental contaminants BPA and BPS can interfere with the isotocinergic signaling pathway and disrupts the establishment of E/I balance in the developing brain, subsequently leading to the onset of a suite of behavioral deficits and neurodevelopmental disorders.

Italian Children Exposure to Bisphenol A: Biomonitoring Data from the LIFE PERSUADED Project

A human biomonitoring (HBM) study on bisphenol A (BPA) in Italian children and adolescents was performed within the LIFE PERSUADED project, considering the residing areas, sex and age. The median urinary BPA level was 7.02 µg/L, with children living in the South of Italy or in urban areas having higher levels than those residing in the North or in rural areas. Children aged 4–6 years had higher BPA levels than those aged 7–10 and 11–14 years, but no differences were detected between sexes. The exposure in Italian children was higher compared to children from other countries, but lower than the HBM guidance value (135 µg/L). The estimated daily intake was 0.17 μg/kg body weight (bw) per day, about 24-fold below the temporary Tolerable Daily Intake of 4 μg/kg bw per day established by the European Food Safety Authority. However, this threshold was exceeded in 1.44% of the enrolled children, raising concern about the overall exposure of Italian young population.

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.

Human-Biomonitoring derived exposure and Daily Intakes of Bisphenol A and their associations with neurodevelopmental outcomes among children of the Polish Mother and Child Cohort Study

BACKGROUND

Bisphenol A (BPA) is an industrial chemical mostly used in the manufacture of plastics, resins and thermal paper. Several studies have reported adverse health effects with BPA exposures, namely metabolic disorders and altered neurodevelopment in children, among others. The aim of this study was to explore BPA exposure, its socio-demographic and life-style related determinants, and its association with neurodevelopmental outcomes in early school age children from Poland.

METHODS

A total of 250 urine samples of 7 year-old children from the Polish Mother and Child Cohort Study (REPRO_PL) were analyzed for BPA concentrations using high performance liquid chromatography with online sample clean-up coupled to tandem mass spectrometry (online-SPE-LC-MS/MS). Socio-demographic and lifestyle-related data was collected by questionnaires or additional biomarker measurements. Emotional and behavioral symptoms in children were assessed using mother-reported Strengths and Difficulties Questionnaire (SDQ). Cognitive and psychomotor development was evaluated by Polish adaptation of the Intelligence and Development Scales (IDS) performed by trained psychologists.

RESULTS

Urinary BPA concentrations and back-calculated daily intakes (medians of 1.8 μg/l and 46.3 ng/kg bw/day, respectively) were similar to other European studies. Urinary cotinine levels and body mass index, together with maternal educational level and socio-economic status, were the main determinants of BPA levels in Polish children. After adjusting for confounding factors, BPA has been found to be positively associated with emotional symptoms (β: 0.14, 95% CI: 0.022; 0.27). Cognitive and psychomotor development were not found to be related to BPA levels.

CONCLUSIONS

This study represents the first report of BPA levels and their determinants in school age children in Poland. The exposure level was found to be related to child emotional condition, which can have long-term consequences including social functioning and scholastic achievements. Further monitoring of this population in terms of overall chemical exposure is required.

Temporal Trends of Phenol, Paraben, and Triclocarban Exposure in California Pregnant Women during 2007-2014

Little is known about temporal trends of pregnant women's exposures to environmental phenols and parabens. We quantified four phenols [bisphenol A (BPA), bisphenol F, bisphenol S, and triclosan), four parabens [butyl paraben, ethyl paraben (ETPB), methyl paraben (MEPB), and propyl paraben (PRPB)], and triclocarban in 760 urine samples collected during 2007-2014 from 218 California pregnant women participating in a high-familial risk autism spectrum disorder cohort. We applied multiple regression to compute least square geometric means of urinary concentrations and computed average annual percent changes. We compared our urinary concentrations with those of other study populations to examine geographic variations in pregnant women's exposure to these target compounds. Urinary concentrations of BPA, MEPB, ETPB, and PRPB in this study population decreased over the study period [percent change per year (95% confidence interval): -5.7% (-8.2%, -3.2%); -13.0% (-18.1%, -7.7%); -5.5% (-11.0%, 0.3%); and -13.3% (-18.3%, -8.1%), respectively] and were consistently lower than those in pregnant women in other U.S. regions during the same study period. In recent years, certain phenols and parabens with known adverse health effects are being regulated or replaced with alternatives, which explains decreased body burdens observed in this study population. Either the national regulations or the advocacy campaigns in California may have influenced exposures or consumer product choices.

Bisphenol A in Africa: A review of environmental and biological levels

Bisphenol A (BPA) is a synthetic ubiquitous environmental toxicant present in many industrial and consumer products. BPA is recognized as an endocrine-disrupting chemical (EDC), and its mechanisms of perturbation of the physiological process include interference with hormone pathways and epigenetic modifications. An increase in industrial productions and food packaging across Africa has resulted in increased utilization of BPA-containing products with a concomitant increase in environmental bioaccumulation and human exposure. In order to assess the extent of this bioaccumulation, we identified, collated, and summarized the levels of BPA that have been reported across Africa. To achieve this aim, we performed a systematic search of four indexing databases to identify articles and extracted the necessary data from the selected articles. Of the 42 publications we retrieved, 42% were on water samples, 22% on food, 20% on human biological fluids, 10% on sediments, soils, and sludge and 6% on consumer and personal care products (PCPs). The highest level of BPA reported in literature across Africa was 251 ng/mL, 384.8 ng/mL, 937.49 ng/g, 208.55 ng/mL, 3,590 μg/g, and 154,820 μg/g for water, wastewater, food, biological fluids, consumer and PCPs, and semisolids, respectively. This review presented a comparative perspective of these levels relative to regulatory limits and levels reported from other continents. Finally, this review highlighted critical needs for the regulation of BPA across Africa in order to stem its environmental and toxicological impact. We hope that this review will stimulate further research in understanding the impact of BPA on health outcomes and wellbeing across Africa.

Understanding the Mechanistic Link between Bisphenol A and Cancer Stem Cells: A Cancer Prevention Perspective

Endocrine disruptors, such as bisphenol A (BPA), have become more frequently present in the environment as contaminants, especially in industrialized countries. Long-term effects of these environmental contaminants in humans are elusive. With their structural similarity to estrogen, many environmental contaminants including BPA, have been shown to mimic the biological functions of estrogen, potentially contributing to the development of breast cancer. It has been well established that BPA exerts estrogenic activity in animal models and in vitro systems. There is a concern for adverse effects from the exposure to BPA in regard to developmental and reproductive toxicities. However, the mechanisms by which BPA promotes breast cancer development remain unknown. Understanding the role of endocrine disruptors and their key mechanisms of action is important for public health, especially by providing a foundation for a better intervention approach in cancer prevention.

Prenatal exposure to bisphenol A and autistic- and ADHD-related symptoms in children aged 2 and5 years from the Odense Child Cohort

BACKGROUND

Bisphenol A (BPA) is a non-persistent chemical with endocrine disrupting abilities used in a variety of consumer products. Fetal exposure to BPA is of concern due to the elevated sensitivity, which particularly relates to the developing brain. Several epidemiological studies have investigated the association between prenatal BPA exposure and neurodevelopment, but the results have been inconclusive.

OBJECTIVE

To assess the association between in utero exposure to BPA and Attention Deficit/Hyperactivity Disorder (ADHD-) symptoms and symptoms of Autism Spectrum Disorder (ASD) in 2 and 5-year old Danish children.

METHOD

In the prospective Odense Child Cohort, BPA was measured in urine samples collected in gestational week 28 and adjusted for osmolality. ADHD and ASD symptoms were assessed with the use of the ADHD scale and ASD scale, respectively, derived from the Child Behaviour Checklist preschool version (CBCL/1½-5) at ages 2 and 5 years. Negative binomial and multiple logistic regression analyses were performed to investigate the association between maternal BPA exposure (continuous ln-transformed or divided into tertiles) and the relative differences in ADHD and ASD problem scores and the odds (OR) of an ADHD and autism score above the 75th percentile adjusting for maternal educational level, maternal age, pre-pregnancy BMI, parity and child age at evaluation in 658 mother-child pairs at 2 years of age for ASD-score, and 427 mother-child pairs at 5 years of age for ADHD and ASD-score.

RESULTS

BPA was detected in 85.3% of maternal urine samples even though the exposure level was low (median 1.2 ng/mL). No associations between maternal BPA exposure and ASD at age 2 years or ADHD at age 5 years were found. Trends of elevated Odds Ratios (ORs) were seen among 5 year old children within the 3rd tertile of BPA exposure with an ASD-score above the 75th percentile (OR = 1.80, 95% CI 0.97,3.32), being stronger for girls (OR = 3.17, 95% CI 1.85,9.28). A dose-response relationship was observed between BPA exposure and ASD-score at 5 years of age (p-trend 0.06) in both boys and girls, but only significant in girls (p-trend 0.03).

CONCLUSION

Our findings suggest that prenatal BPA exposure even in low concentrations may increase the risk of ASD symptoms which may predict later social abilities. It is therefore important to follow-up these children at older ages, measure their own BPA exposure, and determine if the observed associations persist.

Bisphenol A Exposure Disrupts Enamel Formation via EZH2-Mediated H3K27me3

Enamel formation is a serial and complex biological process, during which related genes are expressed progressively in a spatiotemporal manner. This process is vulnerable to environmental cues, resulting in developmental defects of enamel (DDE). However, how environmental factors are biologically integrated during enamel formation is still poorly understood. Here, we investigated the mechanism of DDE elicited by a model endocrine-disrupting chemical, bisphenol A (BPA), in mouse incisors. We show that BPA exposure leads to DDE in mouse incisors, as well as excessive proliferation in dental epithelial stem/progenitor cells. Western blotting, chromatin immunoprecipitation sequencing, and immunofluorescence staining revealed that this effect was accompanied by upregulation of a repressive mark, H3K27me3, in the labial cervical loop of mouse incisors. Perturbation of H3K27me3 methyltransferase EZH2 repressed the level of H3K27me3 and partially attenuated the excessive proliferation in dental epithelial stem/progenitor cells and DDE induced by BPA exposure. Overall, our results demonstrate the essential role of repressive histone modification H3K27me3 in DDE elicited by exposure to an endocrine-disrupting chemical.

Transcriptomic pathway and benchmark dose analysis of Bisphenol A, Bisphenol S, Bisphenol F, and 3,3',5,5'-Tetrabromobisphenol A in H9 human embryonic stem cells

Bisphenol A (BPA) is a chemical used in the manufacturing of plastics to which human exposure is ubiquitous. Numerous studies have linked BPA exposure to many adverse health outcomes prompting the replacement of BPA with various analogues including bisphenol-F (BPF) and bisphenol S (BPS). Other bisphenols are used in various consumer applications, such as 3,3',5,5'-Tetrabromobisphenol A (TBBPA), which is used as a flame retardant. Few studies to date have examined the effects of BPA and its analogues in stem cells to explore potential developmental impacts. Here we used transcriptomics to investigate similarities and differences of BPA and three of its analogues in the estrogen receptor negative, human embryonic stem cell line H9 (WA09). H9 cells were exposed to increasing concentrations of the bisphenols and analyzed using RNA-sequencing. Our data indicate that BPA, BPF, and BPS have similar potencies in inducing transcriptional changes and perturb many of the same pathways. TBBPA, the least structurally similar bisphenol of the group, exhibited much lower potency. All bisphenols robustly impacted gene expression in these cells, albeit at concentrations well above those observed in estrogen-positive cells. Overall, we provide a foundational data set against which to explore the transcriptional similarities of other bisphenols in embryonic stem cells, which may be used to assess the suitability of chemical grouping for read-across and for preliminary potency evaluation.

Sex-specific associations of prenatal exposure to bisphenol A and its alternatives with fetal growth parameters and gestational age

BACKGROUND

Bisphenol A (BPA) can cause detrimental effects on fetal growth. However, the effects of BPA alternatives, such as bisphenol F (BPF) and bisphenol S (BPS), on fetal growth are less known.

OBJECTIVE

To investigate the relationships of prenatal BPA, BPF, and BPS exposures with fetal growth parameters and gestational age.

METHODS

Urinary BPA, BPF, and BPS were measured in 1,197 pregnant women before delivery in a Chinese cohort. The associations of prenatal exposure to BPA, BPF, and BPS with fetal growth parameters and gestational age were examined, and associations stratified by fetal sex were also conducted. We used a restricted cubic splines (RCS) model to examine the dose-response associations between exposures and outcomes.

RESULTS

Maternal urinary BPA and BPF were negatively related to birth length (-0.30 cm, 95% CI: -0.44, -0.15 and -0.21 cm, 95% CI: -0.36, -0.07 comparing the extreme exposure groups, respectively, both p for trends < 0.01). These associations were more pronounced in girls with inverted U-shaped dose-response relationships. Maternal urinary BPA and BPF were positively related to ponderal index (0.05 g/cm³ × 100, 95% CI: 0.01, 0.09 and 0.04 g/cm³ × 100, 95% CI: 0.01, 0.08 comparing the extreme exposure groups, respectively, both p for trends = 0.02), and maternal urinary BPS was associated with shorter gestational age (-0.20 weeks, 95% CI: -0.37, -0.03 comparing the extreme exposure groups, p for trend = 0.02). These associations were only observed in girls and exhibited a linear dose-response relationship.

CONCLUSIONS

Prenatal BPA, BPF, and BPS exposures were associated with detrimental effects on fetal growth parameters, and stronger effects were noted in female infants.

Association Between Bisphenol A Exposure and Risk of All-Cause and Cause-Specific Mortality in US Adults

IMPORTANCE

Bisphenol A (BPA) is a major public health concern because of its high-volume industrial production, ubiquitous exposure to humans, and potential toxic effects on multiple organs and systems in humans. However, prospective studies regarding the association of BPA exposure with long-term health outcomes are sparse.

OBJECTIVE

To examine the association of BPA exposure with all-cause mortality and cause-specific mortality among adults in the United States.

DESIGN, SETTING, AND PARTICIPANTS

This nationally representative cohort study included 3883 adults aged 20 years or older who participated in the US National Health and Nutrition Examination Survey 2003-2008 and provided urine samples for BPA level measurements. Participants were linked to mortality data from survey date through December 31, 2015. Data analyses were conducted in July 2019.

EXPOSURES

Urinary BPA levels were quantified using online solid-phase extraction coupled to high-performance liquid chromatography-isotope dilution tandem mass spectrometry.

MAIN OUTCOMES AND MEASURES

Mortality from all causes, cardiovascular disease, and cancer.

RESULTS

This cohort study included 3883 adults aged 20 years or older (weighted mean [SE] age, 43.6 [0.3] years; 2032 women [weighted, 51.4%]). During 36 514 person-years of follow-up (median, 9.6 years; maximum, 13.1 years), 344 deaths occurred, including 71 deaths from cardiovascular disease and 75 deaths from cancer. Participants with higher urinary BPA levels were at higher risk for death. After adjustment for age, sex, race/ethnicity, socioeconomic status, dietary and lifestyle factors, body mass index, and urinary creatinine levels, the hazard ratio comparing the highest vs lowest tertile of urinary BPA levels was 1.49 (95% CI, 1.01-2.19) for all-cause mortality, 1.46 (95% CI, 0.67-3.15) for cardiovascular disease mortality, and 0.98 (95% CI, 0.40-2.39) for cancer mortality.

CONCLUSIONS AND RELEVANCE

In this nationally representative cohort of US adults, higher BPA exposure was significantly associated with an increased risk of all-cause mortality. Further studies are needed to replicate these findings in other populations and determine the underlying mechanisms.

The association between environmental endocrine disruptors and cardiovascular diseases: A systematic review and meta-analysis

BACKGROUND

Except for known cardiovascular risk factors, long-term exposure to environmental endocrine disruptors (EEDs) - a class of exogenous chemicals, or a mixture of chemicals, that can interfere with any aspect of hormone action - has been shown to increase the risk of cardiovascular diseases (CVDs), which are still controversial.

OBJECTIVE

To conduct a comprehensive systematic review and meta-analysis to estimate the association between EEDs, including nonylphenol (NP), bisphenol A (BPA), polychlorinated biphenyl (PCB), organo-chlorine pesticide (OCP) and phthalate (PAE) exposure and CVD risk.

METHODS

The heterogeneity between different studies was qualitatively and quantitatively evaluated using Q test and I² statistical magnitude, respectively. Subgroup analysis was performed using chemical homologs - a previously unused grouping method - to extract data and perform meta-analysis to assess their exposure to CVD.

RESULTS

Twenty-nine literatures were enrolled with a total sample size of 88891. The results indicated that exposure to PCB138 and PCB153 were the risk factors for CVD morbidity (odds ratio (OR) = 1.35, 95% confidence interval (CI): 1.10-1.66; OR = 1.35, 95% CI: 1.13-1.62). Exposure to organo-chlorine pesticide (OCP) (OR = 1.12, 95% CI: 1.00-1.24), as well as with phthalate (PAE) (OR = 1.11, 95% CI: 1.06-1.17) and BPA (OR = 1.19, 95% CI: 1.03-1.37) were positively associated with CVD risk, respectively. BPA exposure concentration had no correlation with total cholesterol (TC), or low-density lipoprotein (LDL), but exhibited a correlation with gender, waist circumference (WC), high-density lipoprotein (HDL), age, and body mass index (BMI) (standardized mean difference (SMD)) = 1.51; 95% CI: =(1.01-2.25); SMD = 0.16; 95% CI: (0.08-0.23); SMD = -0.19; 95% CI: (-0.27-0.12); SMD = -0.78; 95% CI: (-1.42-0.14); SMD = 0.08; 95% CI: (0.00-0.16).

CONCLUSIONS

EED exposure is a risk factor for CVD. Long-term exposure to EEDs can influence cardiovascular health in humans. A possible synergistic effect may exist between the homologs. The mechanism of which needs to be further explored and demonstrated by additional prospective cohort studies, results of in vitro and in vivo analyses, as well as indices affecting CVD.

Is It Realistic to Propose Determination of a Lifetime Internal Exposome?

Biomonitoring of xenobiotics has been performed for many years in occupational and environmental medicine. It has revealed hidden exposures and the exposure of workers could be reduced. Although most of the toxic effects of chemicals on humans were discovered in workers, the scientific community has more recently focused on environmental samples. In several countries, urinary and blood samples have been collected and analyzed for xenobiotics. Health, biochemical, and clinical parameters were measured in the biomonitoring program of the Unites States. The data were collected and evaluated as group values, comparing races, ages, and gender. The term exposome was created in order to relate chemical exposure to health effects together with the terms genome, proteome, and transcriptome. Internal exposures were mostly established with snapshot measurements, which can lead to an obvious misclassification of the individual exposures. Albumin and hemoglobin adducts of xenobiotics reflect the exposure of a larger time frame, up to 120 days. It is likely that only a small fraction of xenobiotics form such adducts. In addition, adduct analyses are more work intensive than the measurement of xenobiotics and metabolites in urine and/or blood. New technology, such as high-resolution mass spectrometry, will enable the discovery of new compounds that have been overlooked in the past, since over 300,000 chemicals are commercially available and most likely also present in the environment. Yet, quantification will be challenging, as it was for the older methods. At this stage, determination of a lifetime internal exposome is very unrealistic. Instead of an experimental approach with a large number of people, which is economically and scientifically not feasible, in silico methods should be developed further to predict exposure, toxicity, and potential health effects of mixtures. The computer models will help to focus internal exposure investigations on smaller groups of people and smaller number of chemicals.

Resveratrol diminishes bisphenol A-induced oxidative stress through TRPM2 channel in the mouse kidney cortical collecting duct cells

Bisphenol A (BisPH-A) is a latent danger that threatens our health, which we frequently exposure in our modern life (e.g. the widespread use of drinking water in plastic pet bottles). But the BisPH-A induced transient receptor potential melastatin 2 (TRPM2)-mediated oxidative stress and apoptosis in these cells has not been studied yet. Calcium (Ca²⁺) plays an important role in a versatile intracellular signal transduction that works over a wide range to regulate oxidative stress processes. TRPM2 is activated by oxidative stress and it has emerged as an important Ca²⁺ signaling mechanism in a variety of cells, contributing many cellular functions including cell death. Resveratrol (RESV), which belongs to the polyphenol group, acts as an antioxidant, eliminating cellular oxidative stress and increasing the body's resistance to diseases. The current study aimed to elucidate the effect of antioxidant resveratrol on TRPM2-mediated oxidative stress induced by BisPH-A exposure in the mouse kidney cortical collecting duct cells (mpkCCD_cl4). The cells were divided into four groups as control, resveratrol (50 µM for 24 h), BisPH-A (100 µM for 24 h) and BisPH-A + RESV. Intracellular free Ca²⁺ concentrations and TRPM2 channel currents were high in BisPH-A treated cells, but decreased with resveratrol treatment. In addition, BisPH-A induced mitochondrial membrane depolarization, reactive oxygen species (ROS), caspase 3, caspase 9 and apoptosis values were decreased by the resveratrol treatment. In conclusion, resveratrol protected cells from BisPH-A induced oxidative damage. In this study, we showed that TRPM2 channel mediates this protective effect of resveratrol.

Exposure to Endocrine Disrupting Chemicals in the Dutch general population is associated with adiposity-related traits

Endocrine Disrupting Chemicals (EDCs) have been linked to a variety of cardiometabolic diseases. Yet, few studies have investigated the exposure to EDCs and cardiometabolic health taking lifestyle into account. We aimed to assess exposure to five parabens, three bisphenols and thirteen metabolites of in total eight phthalates in a general Dutch population and to investigate their association with cardiometabolic traits. In 662 adult subjects from the population-based Lifelines cohort, 21 EDC analytes were measured in 24-hour urine collected in 2012, using LC-MS/MS. Association analyses between cardiometabolic traits and EDC concentrations were performed using multivariate linear models adjusting for age, sex, education, smoking, diabetes, physical activity and caloric intake. Quartile analyses were performed to assess linearity. Bisphenol A, four parabens and eight phthalate metabolites were detected in 84-100% of the samples. Adjusted associations for MiBP and MBzP and adiposity-related traits were robust for multiple testing (Beta’s, BMI: 1.12, 2.52; waist circumference: 0.64, 1.56, respectively; FDR < 0.009). Associations for triglyceride, HDL-cholesterol, glucose and blood pressure were not. Linearity was confirmed for significant associations. Exposure to EDCs in the Dutch population is ubiquitous. We found direct associations between phthalates and adiposity-related traits. Prospective studies are needed to confirm these findings.

Relationship between seafood consumption and bisphenol A exposure: the Second Korean National Environmental Health Survey (KoNEHS 2012-2014)

Background

This study aimed to identify the relationship between exposure to bisphenol A (BPA) and seafood consumption using a nationally representative data of the general Korean population.

Methods

This study was conducted on 5,402 adults aged 19 years and older (2,488 men, 2,914 women) based on the second Korean National Environmental Health Survey (2012–2014). We stratified the data according to gender and analyzed urinary BPA concentrations in terms of sociodemographic characteristics, health behavior, dietary factor, and seafood consumption. In the high and low BPA exposure groups, the odds ratios (ORs) were calculated using logistic regression analysis according to the top 75th percentile concentration.

Results

In men, large fish and tuna and other seafood categories had significantly higher ORs before and after adjustment in the group who consumed seafood more than once a week than in the group who rarely consumed seafood, with an adjusted value of 1.97 (95% confidence interval [CI]: 1.12–3.48) and 1.74 (95% CI: 1.10–2.75), respectively. In the shellfish category, the unadjusted OR was 1.61 (95% CI: 1.00–2.59), which was significantly higher in the group who consumed seafood more than once a week than in the group who rarely consumed seafood. However, the OR after adjusting for the variables was not statistically significant. In women, the frequency of seafood consumption and the concentration of urinary BPA were not significantly associated.

Conclusions

BPA concentration was higher in men who frequently consumed large fish and tuna, shellfish and other seafood in this study.

Bisphenol A (BPA) induces progesterone receptor expression in an estrogen receptor α-dependent manner in perinatal brain

Bisphenol A (BPA) is a xenoestrogen that is prevalent in the environment of industrialized nations due its use in the production of many plastic household items. Virtually all adults in the U.S. have detectable levels of BPA in urine and it can be measured in fetal serum and in breastmilk, making developmental exposure a particular concern. The present study utilizes a progesterone receptor (PR) expression bioassay to assess the estrogen receptor α (ERα)-dependent effects of BPA in fetal rodent brain following maternal exposure. Maternal ingestion of 10 μg/kg/day, but not 50 μg/kg/day, BPA from gestational day 14-22 significantly increased levels of PR immunoreactivity (PRir) in the medial preoptic nucleus (MPN) of female offspring. PR expression in the perinatal MPN is highly dependent on the activation of ERα, but not ERβ, by estrogens. Indeed, injections of BPA (5 μg/kg) to neonates from postnatal day 2-4 (P2-4) significantly increased PR expression in the MPN of postnatal day 5 females compared to the MPN of females administered the oil vehicle. However, pretreatment with the ER antagonist, ICI 182,780 from P1-4 significantly attenuated the effects of BPA on PR expression, indicating an ERα-dependent mechanism. The present results also demonstrate a non-monotonic effect of BPA on the direct expression of a transcription factor in developing brain.

Association of urinary bisphenols and triclosan with thyroid function during early pregnancy

BACKGROUND

Bisphenols and triclosan are considered as potential thyroid disruptors. While mild alterations in maternal thyroid function can result in adverse pregnancy and child developmental outcomes, there is still uncertainty whether bisphenols or triclosan can interfere with thyroid function during pregnancy.

OBJECTIVES

We aimed to investigate the association of urinary bisphenol A (BPA), bisphenol S (BPS), bisphenol F (BPF) and triclosan with early pregnancy thyroid function.

METHODS

This study was embedded in the Swedish Environmental Longitudinal, Mother and child, Asthma and allergy study (SELMA), a population-based prospective pregnancy cohort. In total, 1996 participants were included in the current study. Maternal urinary concentrations of three bisphenols and triclosan, collected at median (95% range) 10 (6-14) weeks of pregnancy as well as serum concentrations of thyroid stimulating hormone (TSH), free thyroxine (FT4), free triiodothyronine (FT3), total thyroxine (TT4), and total triiodothyronine (TT3) were measured.

RESULTS

Higher BPA levels were associated with lower TT4 concentrations (non-monotonic, P = 0.03), a lower FT4/FT3 ratio (β [SE] -0.02 [0.01], P = 0.03) and a lower TT4/TT3 ratio (β [SE] -0.73 [0.27], P = 0.008). Higher BPF levels were associated with a higher FT3 (β [SE] 0.01 [0.007], P = 0.04). There were no associations between other bisphenols or triclosan and absolute TSH, (F)T4 or (F)T3 concentrations. The association of BPA with thyroid function differed with gestational age. The negative association of BPA with FT4/FT3 and TT4/TT3 ratios was only apparent in early but not late gestation (P for interaction: 0.003, 0.008, respectively).

CONCLUSION

These human data during pregnancy substantiate experimental findings suggesting that BPA could potentially affect thyroid function and deiodinase activities in early gestation.

Prenatal maternal and childhood bisphenol a exposure and brain structure and behavior of young children

BACKGROUND

Bisphenol A (BPA) is commonly used in the manufacture of plastics and epoxy resins. In North America, over 90% of the population has detectable levels of urinary BPA. Human epidemiological studies have reported adverse behavioral outcomes with BPA exposure in children, however, corresponding effects on children's brain structure have not yet been investigated. The current study examined the association between prenatal maternal and childhood BPA exposure and white matter microstructure in children aged 2 to 5 years, and investigated whether brain structure mediated the association between BPA exposure and child behavior.

METHODS

Participants were 98 mother-child pairs who were recruited between January 2009 and December 2012. Total BPA concentrations in spot urine samples obtained from mothers in the second trimester of pregnancy and from children at 3-4 years of age were analyzed. Children participated in a diffusion magnetic resonance imaging (MRI) scan at age 2-5 years (3.7 ± 0.8 years). Associations between prenatal maternal and childhood BPA and children's fractional anisotropy and mean diffusivity of 10 isolated white matter tracts were investigated, controlling for urinary creatinine, child sex, and age at the time of MRI. Post-hoc analyses examined if alterations in white matter mediated the relationship of BPA and children's scores on the Child Behavior Checklist (CBCL).

RESULTS

Prenatal maternal urinary BPA was significantly associated with child mean diffusivity in the splenium and right inferior longitudinal fasciculus. Splenium diffusivity mediated the relationship between maternal prenatal BPA levels and children's internalizing behavior (indirect effect: β = 0.213, CI [0.0167, 0.564]). No significant associations were found between childhood BPA and white matter microstructure.

CONCLUSIONS

This study provides preliminary evidence for the neural correlates of BPA exposure in humans. Our findings suggest that prenatal maternal exposure to BPA may lead to alterations in white matter microstructure in preschool aged children, and that such alterations mediate the relationship between early life exposure to BPA and internalizing problems.

Canned food intake and urinary bisphenol a concentrations: a randomized crossover intervention study

Bisphenol A (BPA) is an endocrine disruptor. To evaluate the effect of canned food consumption on internal BPA dose, urinary BPA concentrations were measured before and after intake of canned foods. This study applied a randomized crossover design, recruited 20 healthy volunteers, and divided them into two groups. One group consumed canned food; the other group consumed fresh food. After a 1-day washout, the dietary interventions were reversed. In each period, urine samples were collected immediately before meals and then 2 h, 4 h, and 6 h after meals. A mixed-effects model was used to assess BPA changes over time. Our results showed urinary BPA concentrations increased after consumption of canned food. Specifically, urinary BPA concentrations significantly differed between consumption of canned food and fresh food at 2 h, 4 h, and 6 h after intake (p values of 0.001, < 0.001, and < 0.001, respectively). Mean BPA concentrations at 2 h, 4 h, and 6 h after meals were 152%, 206%, and 79% higher, respectively, than mean BPA concentrations before meals. Urine concentration profiles of canned food intake showed that peaks were at 4 h, the increase diminished at 6 h, and returned to baseline levels at 24 h after intake. Therefore, dietary intervention and a 1-day washout period are effective for limiting internal BPA burden. This study provides convincing evidence of a human exposure route to BPA and a basis for designing interventions to mitigate exposure.

Trends and disparities in urinary BPA concentrations among U.S. emerging adults

BACKGROUND

Emerging adulthood (ages 18-25 years) is a key turning point in the life course characterized by particularly poor eating behaviors (e.g., low in fruits and vegetables, and high in fast food) and weight gain. Emerging adults are also prime consumers of personal care and other consumer products that may result in differential exposures to environmental contaminants, such as Bisphenol A (BPA), compared to adults aged 26+ years. This is of concern given BPA has been associated with adverse health outcomes such as obesity, metabolic disorders, miscarriage, infertility and breast cancer. However, no research has examined exposure to BPA among emerging adults.

OBJECTIVE

To assess trends of exposure to urinary BPA among a representative sample of emerging adults compared to adults aged 26+ years. Secondarily, we aimed to identify differential associations between BPA concentrations and sociodemographic characteristics and BMI by age group.

METHODS

This study uses National Health and Examination Surveys (NHANES) over 2003-2014 to test differences in BPA concentrations comparing emerging adults to adults aged 26+ years. Generalized linear models predicting log BPA by age group and sex, race/ethnicity, education, income, and food security status, and generalized linear models predicting BMI by log BPA, both age group and age as a continuous variable, sex, race/ethnicity, education, income, and food security status were conducted. Interactions with age group (i.e., age group x sex) were examined for the mutually adjusted models. All models controlled for survey year, month, and time of day, and were run with, and without, an adjustment for urinary creatinine.

RESULTS

In models adjusted, and not adjusted, for urinary creatinine, emerging adults had a higher log BPA concentration than adults aged 26+ years (β=0.153, p=0.004; β=0.544, p<0.001), and a significantly steeper decline in BPA concentration between 2003-2004 and 2013-2014 than adults aged 26+ years (ß=-0.051, p=0.002; ß=-0.071, p=0.001). Males' log BPA concentration were lower than that for females when urinary creatinine was included in the model, and higher when urinary creatinine was excluded from the model (ß=-0.188, p<0.001; β=0.203, p<0.001). Higher income was significantly associated with lower log BPA concentration (ß=-0.220, p<0.001; ß=-0.166, p<0.001). A significant interaction between emerging adult age group and food security status was observed, which was associated with higher BPA exposures. Log BPA concentration was associated with BMI only when urinary creatinine was excluded from the models (urinary creatinine included: β=0.031, p=0.747; β=0.022, p=0.815, urinary creatinine excluded: β=0.528, p<0.001; β=0.552, p<0.001).

CONCLUSION

Findings indicate that emerging adults had higher BPA exposures than adults aged 26+ years in 2003-2004, and that emerging adults' exposure level has decreased faster than that of adults aged 26+ years. There were suggestions that the BPA concentration of emerging adults in 2013-2014 was lower than that for adults aged 26+ years, and that BPA exposure is associated with higher BMI. Our results highlight the need for additional research to identify the sources and routes of exposure to BPA and BPA replacements among emerging adults and to better characterize the variability in exposure. Intervention studies are needed to assist emerging adults in limiting their exposure to BPA, and potentially also the BPA alternatives.

Linking Probabilistic Exposure and Pharmacokinetic Modeling To Assess the Cumulative Risk from the Bisphenols BPA, BPS, BPF, and BPAF for Europeans

The bisphenols S, F, and AF (BPS, BPF, and BPAF) are used to replace the endocrine disrupting chemical bisphenol A (BPA) while exerting estrogenic effects of comparable potency. We assessed the cumulative risk for the aforementioned BPs in Europe and compared the risk before and after the year 2011, which was when the first BPA restrictions became effective. For this, we probabilistically modeled external exposures from food, personal care products (PCPs), thermal paper, and dust (using the tools MCRA and PACEM for exposures from food and PCPs, respectively). We calculated internal concentrations of unconjugated BPs with substance-specific PBPK models and cumulated these concentrations normalized by estrogenic potency. The resulting mean internal cumulative exposures to unconjugated BPs were 3.8 and 2.1 ng/kg bw/day before and after restrictions, respectively. This decline was mainly caused by the replacement of BPA by BPS in thermal paper and the lower dermal uptake of BPS compared to BPA. However, the decline was not significant: the selected uncertainty intervals overlapped (P2.5-P97.5 uncertainty intervals of 2.7-4.9 and 1.3-6.3 ng/kg bw/day before and after restrictions, respectively). The upper uncertainty bounds for cumulative exposure were higher after restrictions, which reflects the larger uncertainty around exposures to substitutes compared to BPA.

Development and Interlaboratory Validation of Two Fast UPLC-MS-MS Methods Determining Urinary Bisphenols, Parabens and Phthalates

People are constantly exposed to a wide variety of chemicals. Some of these compounds, such as parabens, bisphenols and phthalates, are known to have endocrine disrupting potencies. Over the years, these endocrine disrupting chemicals (EDCs) have been a rising cause for concern. In this study, we describe setup and validation of two methods to measure EDCs in human urine, using ultra-performance liquid chromatography tandem mass spectrometry. The phenol method determines methyl-, ethyl-, propyl-, n-butyl- and benzylparaben and bisphenol A, F and S. The phthalate method determines in total 13 metabolites of dimethyl, diethyl, diisobutyl, di-n-butyl, di(2-ethylhexyl), butylbenzyl, diiso-nonyl and diisodecyl phthalate. Runtime was 7 and 8 min per sample for phenols and phthalates, respectively. The methods were validated by the National Institute of Standards & Technology (NIST) for 13 compounds. In addition, EDCs were measured in forty 24-h urine samples, of which 12 EDCs were compared with the same samples measured in an established facility (Rigshospitalet, Copenhagen, Denmark). The intra-assay coefficient of variability (CV) was highest at 10% and inter-assay CV was highest at 12%. Recoveries ranged from 86 to 115%. The limit of detection ranged from 0.06 to 0.43 ng/mL. Of 21 compounds, 10 were detected above limit of detection in ≥93% of the samples. Eight compounds were in accordance to NIST reference concentrations. Differences in intercept were found for two compounds whereas slope differed for six compounds between our method and that used in the Danish facility. In conclusion, we set up and validated two high-throughput methods with very short runtime capable of measuring 5 parabens, 3 bisphenols and 13 different metabolites of 8 phthalates. Sensitivity of the phenol method was increased by using ammonium fluoride in the mobile phase.

Bisphenol A co-exposure effects: a key factor in understanding BPA's complex mechanism and health outcomes

Bisphenol A (BPA) is an environmental endocrine disrupting chemical widely used in the production of consumer products, such as polycarbonate plastics, epoxies, and thermal receipt paper. Human exposure to BPA is ubiquitous due to its high-volume production and use. BPA exposure has been associated with obesity, diabetes, reproductive disorders, and cancer. Yet, the molecular mechanisms or modes of action underlying these disease outcomes are poorly understood due to the pleiotropic effects induced by BPA. A further confounding factor in understanding BPA's impact on human health is that co-exposure of BPA with endogenous and exogenous agents occurs during the course of daily life. Studies investigating BPA exposure effects and their relationship to adverse health outcomes often ignore interactions between BPA and other chemicals present in the environment. This review examines BPA co-exposure studies to highlight potentially unexplored mechanisms of action and their possible associations with the adverse health effects attributed to BPA. Importantly, both adverse and beneficial co-exposure effects are observed between BPA and natural chemicals or environmental stressors in in vitro and in vivo models. These interactions clearly influence cellular responses and impact endpoint measures and need to be considered when evaluating BPA exposures and their health effects.