Total Bisphenol A Research Articles

Dietary bisphenols exposure as an influencing factor of body mass index

BackgroundOver the past three decades, there has been a significant increase in the prevalence and incidence of overweight and obesity worldwide. The obesogen hypothesis suggests that certain external agents may affect pathways related to fat accumulation and energy balance by stimulating fat cell differentiation and proliferation. Previous research has indicated that exposure to bisphenol A (BPA) and some of its analogues may influence fat accumulation by promoting the transformation of preadipocytes into adipocytes. This study aimed to assess the possible contribution of dietary bisphenol exposure to the odds of developing overweight and obesity in a sample of Spanish children according to sex.MethodsDietary and anthropometric data were collected from 179 controls and 124 cases schoolchildren aged 3–12 years. Dietary exposure to BPA and bisphenol S (BPS) was assessed using a food consumption frequency questionnaire. Logistic regression models were used to assess the influence of dietary exposure to bisphenols on overweight and obesity stratified by sex.ResultsFor females, cases had significantly higher exposure to BPA from meat and eggs compared to controls (median = 319.55, interquartile range (IQR) = 176.39–381.01 vs 231.79 (IQR) = 162.11–350.19, p-value = 0.046). Diet quality was higher for controls (6.21 (2.14) vs 4.80 (2.24) p < 0.001) among males independently of a high or low exposure to bisphenols. However, higher diet quality was observed for female controls with an high exposure of total bisphenols (6.79 (2.04) vs 5.33 (2.02) p = 0.031). Females exposed to high levels of BPA from meat and eggs had higher likelihood of being overweight and obese (adjusted Odds Ratio = 2.70, 95% confidence interval = 1.00 – 7.32). However, no consistent associations were found in males.ConclusionsHigh BPA levels from meat and eggs were positively associated with overweight and obesity in females. The dietary intake of BPA in the schoolchildren in the present study was much higher than the acceptable daily intake established by EFSA for the last year.

Occurrence and profiles of bisphenol A and its analogues in marine shrimps from Tianjin and their implications for human exposure

Bisphenols, a class of compounds with endocrine-disrupting characteristics, encompassing its effects on reproduction, nervous and immune systems. Diet represents the principal route of bisphenols intake, prompting concerns about dietary exposure. In this study, the occurrence and content of nine bisphenols in 96 marine shrimps from Tianjin were detected and analysed using ultra high performance liquid chromatography mass spectrometer and solid-phase extraction. The analytical method was validated to demonstrate reliable analytical performance. The results revealed that bisphenol A was detected in the majority of the samples, with the highest detection rate among the nine bisphenols, followed by bisphenol S, while the remaining bisphenols were not detected. A discernible age-related trend was identified in the assessment of dietary exposure, whereby exposure levels increased with decreasing age. Furthermore, regional discrepancies were observed, yet no gender-based distinctions were discerned. The estimated daily intake to total bisphenols through marine shrimp in this study was lower than the current tolerable daily intake set by the European Food Safety Authority, and it can be assumed that the risk of exposure to the nine bisphenols investigated through dietary is acceptable. However, given the recently proposed draft values by the European Food Safety Authority and the higher exposures observed in children and teenagers, further surveillance and dietary guidance is required. To our knowledge, this is the first study in Tianjin to evaluate the health risks associated with bisphenol A and its analogues via marine shrimp, which can monitor dietary safety and protect population health.

Sex-Specific Associations between Prenatal Exposure to Bisphenols and Phthalates and Infant Epigenetic Age Acceleration.

We examined whether prenatal exposure to two classes of endocrine-disrupting chemicals (EDCs) was associated with infant epigenetic age acceleration (EAA), a DNA methylation biomarker of aging. Participants included 224 maternal-infant pairs from a Canadian pregnancy cohort study. Two bisphenols and 12 phthalate metabolites were measured in maternal second trimester urines. Buccal epithelial cell cheek swabs were collected from 3 month old infants and DNA methylation was profiled using the Infinium MethylationEPIC BeadChip. The Pediatric-Buccal-Epigenetic tool was used to estimate EAA. Sex-stratified robust regressions examined individual chemical associations with EAA, and Bayesian kernel machine regression (BKMR) examined chemical mixture effects. Adjusted robust models showed that in female infants, prenatal exposure to total bisphenol A (BPA) was positively associated with EAA (B = 0.72, 95% CI: 0.21, 1.24), and multiple phthalate metabolites were inversely associated with EAA (Bs from -0.36 to -0.66, 95% CIs from -1.28 to -0.02). BKMR showed that prenatal BPA was the most important chemical in the mixture and was positively associated with EAA in both sexes. No overall chemical mixture effects or male-specific associations were noted. These findings indicate that prenatal EDC exposures are associated with sex-specific deviations in biological aging, which may have lasting implications for child health and development.

Evaluation of Exposure to Bisphenol Analogs through Canned and Ready-to-Eat Meal Consumption and Their Possible Effects on Blood Pressure and Heart Rate.

Bisphenols are endocrine-disrupting chemicals used in plastics and resins for food packaging. This study aimed to evaluate the exposure to bisphenol A (BPA), bisphenol S (BPS), and bisphenol F (BPF) associated with the consumption of fresh, canned, and ready-to-eat meals and determine the effects of bisphenols on blood pressure and heart rate. Forty-eight healthy young adults were recruited for this study, and they were divided into the following three groups: fresh, canned, and ready-to-eat meal groups. Urine samples were collected 2, 4, and 6 h after meal consumption, and blood pressure and heart rate were measured. The consumption of ready-to-eat meals significantly increased urine BPA concentrations compared with canned and fresh meal consumption. No significant difference in BPS and BPF concentrations was observed between the groups. The consumption of ready-to-eat meals was associated with a significant increase in systolic blood pressure and pulse pressure and a marked decrease in diastolic blood pressure and heart rate. No significant differences were noted in blood pressure and heart rate with canned and fresh meal consumption. It can be concluded that total BPA concentration in consumed ready-to-eat meals is high. High BPA intake causes increase in urinary BPA concentrations, which may, in turn, lead to changes in some cardiovascular parameters.

Conjugated metabolites of bisphenol A and bisphenol S in indoor dust, outdoor dust, and human urine

Bisphenol A (BPA) and bisphenol S (BPS) have been widely spread in the global environment. However, for conjugated BPA and BPS metabolites, limited studies have investigated their occurrence in environmental matrices. We collected paired indoor and outdoor dust (n = 97), as well as human urine (n = 153) samples, from residential houses in Quzhou, China, and measured these samples for 8 conjugated BPA and BPS metabolites. Three BPA metabolites were found in collected indoor and outdoor dust, with BPA sulfate (mean 0.75 and 1.3 ng/g, respectively) and BPA glucuronide (0.13 and 0.26 ng/g) being more abundant. BPA conjugates accounted for a mean of 42 and 56% of total BPA (sum of conjugated BPA and BPA metabolites) in indoor and outdoor dust, respectively. BPS sulfate (mean 0.29 and 0.82 ng/g, respectively) had consistently higher concentrations than BPS glucuronide (0.13 and 0.27 ng/g) in indoor and outdoor samples. BPS conjugates contributed a mean 32% and 45% of total BPS (sum of BPS and BPS metabolites) in indoor and outdoor dust, respectively. Moreover, conjugated BPA and BPS metabolites in indoor or outdoor dust were not significantly correlated with those in urine from residents. Overall, this study first demonstrates the wide presence of conjugated BPA and BPS metabolites, besides BPA and BPS, in indoor and outdoor dust. These data are important for elucidating the sources of conjugated BPA and BPS metabolites in the human body.

Evaluating associations of bisphenol and phthalate exposure with time to pregnancy and subfecundity in a New York City pregnancy cohort

It is important to understand the impact of consumer chemical exposure and fecundity, a couple's measure of probability of successful conception, given approximately 15% of couples experience infertility. Prior research has generally found null associations between bisphenol and phthalate exposure and fecundability, measured via time to pregnancy (TTP). However, this research has not been updated with current chemical exposures and have often lacked diversity in their study populations. We evaluated the associations between common bisphenol and phthalate chemical exposure groups and TTP as well as subfecundity (TTP>12 months) in the New York University Children's Health Study, a diverse pregnancy cohort from 2016 onward. Using first-trimester spot-urine samples to measure chemical exposure and self-reported TTP from first-trimester questionnaires, we observed a significant adverse association between total bisphenol exposure and certain phthalate groups on TTP and odds of subfecundity. Furthermore, in a mixtures analysis to explore the joint effects of the chemical groups on the outcomes, we found evidence of a potential interaction between total bisphenol exposure and low-molecular weight phthalates on TTP. Future research should continue to update our knowledge regarding the complex and potentially interacting effects of these chemicals on reproductive health.

Biomonitoring of bisphenol A (BPA) and bisphenol analogues in human milk from South Africa and Canada using a modified QuEChERS extraction method

A sensitive modified QuEChERS extraction method was developed to assess the levels of free and conjugated bisphenols (BPs) in human milk collected between 2018 and 2019 from two regions of South Africa (the Limpopo Province Vhembe district, n = 194; Pretoria, n = 193) and Canada (Montreal, n = 207). Total BPA (free and conjugated) and BPS were the predominant bisphenols detected in samples from Vhembe and Pretoria, whereas total BPS was the predominant bisphenol detected in Montreal samples. The levels of total BPA in samples from Vhembe and Pretoria ranged between < MDL-18.61 and <MDL-19.38 ng/mL, with medians of 1.03 ng/mL and 0.69 ng/mL and detection frequencies of 73% and 68%, respectively. The speciation analysis of BPA revealed a predominantly conjugated form in South African samples. In contrast, total BPA was detected in only one milk sample from Montreal. Total BPS levels were lower than BPA in South Africa, with detection frequencies of 57% and 21% in Vhembe and Pretoria, respectively. In contrast, total BPS was the major BP detected (42%) in Montreal (up to 4.42 ng/mL). BPAF was found exclusively in South Africa, with detection frequencies for total BPAF of 40% and 9% in Vhembe (<MDL-12.41 ng/mL) and Pretoria (<MDL-0.11 ng/mL), respectively. To our knowledge, this is one of the first studies to detect bisphenols in human milk from data-scarce countries such as South Africa and to highlight the notable disparities in the types and levels of bisphenols detected across two distinct countries (Canada and South Africa).

Alternatives Exert Higher Health Risks than Bisphenol A on Indo-Pacific Humpback Dolphins.

The detrimental effects of bisphenol (BP) exposure are a concern for vulnerable species, Indo-Pacific humpback dolphins (Sousa chinensis). To investigate the characteristics of BP profiles and their adverse impact on humpback dolphins, we assessed the concentrations of six BPs, including bisphenol A (BPA), bisphenol S (BPS), bisphenol F (BPF), bisphenol AF (BPAF), bisphenol B (BPB), and bisphenol P (BPP) in blubber (n = 26) and kidney (n = 12) of humpback dolphins stranded in the Pearl River Estuary, China. BPS accounted for the largest proportion of the total bisphenols (∑BPs) in blubber (55%) and kidney (69%). The concentration of ∑BP in blubber was significantly higher than that in the kidney and liver. The EC50 values of five BPA alternatives were lower than those of BPA in humpback dolphin skin fibroblasts (ScSF) and human skin fibroblasts (HSF). ScSF was more sensitive to BPS, BPAF, BPB, and BPP than HSF. The enrichment pathway of BPA was found to be associated with inflammation and immune dysregulation, while BPP and BPS demonstrated a preference for genotoxicity. BPA, BPP, and BPS, which had risk quotients (RQs) > 1, were found to contribute to subhealth and chronic disease in humpback dolphins. According to the EC50-based risk assessment, BPS poses a higher health risk than BPA for humpback dolphins. This study successfully evaluated the risks of bisphenols in rare and endangered cetacean cell lines using a noninvasive method. More in vivo and in field observations are necessary to know whether the BPA alternatives are likely to be regrettable substitutions.

Influence of Gut Microbiota on Metabolism of Bisphenol A, a Major Component of Polycarbonate Plastics.

Bisphenol A (BPA) is a major component of polycarbonate plastics and epoxy resins. While many studies have investigated the effect BPA exposure has upon changes in gut microbial communities, the influence of gut microbiota on an organism's ability to metabolize BPA remains comparatively unexplored. To remedy this, in this study, Sprague Dawley rats were intermittently (i.e., at a 7-day interval) or continuously dosed with 500 μg BPA/kg bw/day for 28 days, via oral gavage. In the rats which underwent the 7-day interval BPA exposure, neither their metabolism of BPA nor their gut microbiota structure changed greatly with dosing time. In contrast, following continuous BPA exposure, the relative level of Firmicutes and Proteobacteria in the rats' guts significantly increased, and the alpha diversity of the rats' gut bacteria was greatly reduced. Meanwhile, the mean proportion of BPA sulfate to total BPA in rat blood was gradually decreased from 30 (on day 1) to 7.4% (by day 28). After 28 days of continuous exposure, the mean proportion of BPA glucuronide to total BPA in the rats' urine elevated from 70 to 81%, and in the rats' feces the mean proportion of BPA gradually decreased from 83 to 65%. Under continuous BPA exposure, the abundances of 27, 25, and 24 gut microbial genera were significantly correlated with the proportion of BPA or its metabolites in the rats' blood, urine, and feces, respectively. Overall, this study principally aimed to demonstrate that continuous BPA exposure disrupted the rats' gut microbiota communities, which in turn altered the rats' metabolism of BPA. These findings contribute to the better understanding of the metabolism of BPA in humans.

Occurrence of bisphenol diglycidyl ethers and bisphenol analogs, and their associations with DNA oxidative damage in pregnant women

Bisphenol diglycidyl ethers (BDGEs) and Bisphenol A and its analogs (bisphenols) may have the same exposure routes and coexposure phenomenon in sensitive populations such as pregnant women. Previous biomonitoring studies on BDGEs are limited. Levels of fifteen bisphenols, six BDGEs and the DNA oxidative damage biomarker 8-hydroxy-2-deoxyguanosine (8-OHdG) were measured in the urine of pregnant women recruited in south China (n = 358). We aimed to provide the occurrence of bisphenols and BDGEs in pregnant women, and to investigate the potential relationship between their exposure and oxidative stress. Bisphenol A, bisphenol S, bisphenol F, bisphenol AP and all BDGEs (except for BADGE·2HCl) were frequently detected. The total concentrations of all bisphenols and BDGEs were 0.402–338 and 0.104–32.5 ng/mL, with geometric means of 2.87 and 2.48 ng/mL, respectively. BFDGE was the most abundant chemical of BDGEs, with a median concentration of 0.872 ng/mL, followed by BADGE·H2O·HCl (0.297 ng/mL). Except for pre-pregnancy obesity, maternal age/height, employment, fasting in the morning and parity did not affect the urinary concentrations of BDGEs. Significant and weak correlations were observed between concentrations (unadjusted) of total bisphenols and BDGEs (r = 0.389, p < 0.01), indicating their similar sources and exposure routes. The biomarker 8-OHdG was detected in all samples, with concentrations ranging from 1.98 to 32.6 ng/mL (median: 9.96 ng/mL). Levels of 8-OHdG were positively correlated with urinary several bisphenol concentrations (adjusted β range: 0.037–0.089, p < 0.05) but were not correlated with those of BDGEs. Further studies should focus on whether BDGEs and bisphenols exert combined effects on oxidative stress. Our study provided the first BDGEs exposure data in pregnant women and indicated that BDGEs exposure was highly prevalent in pregnant women as early as 2015 in south China.

Risk Assessment of Bisphenol A in the Korean General Population

Bisphenol A (BPA) is not a natural substance but is produced artificially during the manufacturing of various plastics. Exposure to (BPA) is a pervasive and growing concern. BPA has recently been classified as a substance of great concern by the European Union (EU). BPA is suspected to be associated with several chronic human health effects. In this study, the estimated total BPA exposure levels were based on biomonitoring of the general population, and exposure levels ranged from a mean of 0.031 to 0.042 µg/kg body weight (bw)/day, reaching up to 0.104 µg/kg bw/day in the high-exposure population. When comparing the exposure levels of BPA to some toxicological effects, such as immunotoxicity and thyroid function, a sufficient exposure margin was not secured in the high-exposure group. Food is considered the main source of exposure for the general population, but other sources of exposure may exist in the high-exposure group. As humans are primarily exposed to BPA through food, water, house dust, skin contact, and air, integrated risk management is required to reduce BPA exposure. In addition, it is considered necessary to develop a new methodology for human health evaluation in response to low-dose exposure to BPA.

Bisphenol A exposure and symptoms of anxiety and depression among women of reproductive age

Bisphenol A (BPA) is a chemical compound used in multiple areas, including the manufacture of food packaging and containers. Dietary exposure accounts for &gt;90% of total exposure. It is considered an endocrine disruptor, as it is suspected to adversely affect fetal development during intrauterine life and contribute to the development of obesity, diabetes and cardiovascular disease and mental health in adulthood. European law (Regulation (UE) 321/2011) banned BPA from polycarbonate infant feeding bottles, but it remains authorized for all other products with a tolerable daily intake of 4 μg/kg body weight/day (EFSA2015). We conducted a cross-sectional study of 56 women aged 18-40y to investigate the association between BPA exposure and the presence of anxiety and depressive symptoms. Subjects, recruited at ICANS, University of Milan, completed the STAI2 and QD questionnaires to investigate anxiety and depressive symptoms, respectively. A blood sample was taken to determine exposure to total and unconjugated-BPA (metabolically active form). After adjustment for age, BMI, smoking and physical activity, total BPA (log-transform for linearity) was not associated with anxiety and depression, whereas unconjugated-BPA (transformed in square root for linearity) was significant associated with depression score (β(BPA) = 0.11, 95% CI: 0.01, 0.21; p=0.042). Our data suggest that BPA exposure is associated with depressive symptoms in women in reproductive age.

Estimated exposure to bisphenol A in breastfed and breastfed plus formula-fed infants in Turkey: a comparison study

This study aimed to estimate and compare dietary exposure to bisphenol A (BPA) in exclusively breastfed (EBF) and breastfed plus formula-fed (BF + FF) infants. A total of 70 mothers and their 0–6 month-old infants (40 in the EBF group and 30 in BF + FF group) were included in the study. After the questionnaire form was applied to the mothers, maternal breast milk, infant formula, and infant urine were collected from mother-infant dyads. Total BPA levels in breast milk, infant formula, and infant urine samples were analyzed by the high-pressure liquid chromatography (HPLC). While BPA was detected in 92.5% of the breast milk samples in the EBF group (mean ± SD = 0.59 ± 0.29 ng/mL), BPA was detected in all of the breast milk samples in the BF + FF group (mean ± SD= 0.72 ± 0.37 ng/mL) (p < 0.05). Similarly, 100% of the infant formula samples in the BF + FF group had detectable levels of BPA (mean ± SD = 7.54 ± 1.77 ng/g formula). The mean urinary BPA levels in the EBF infants (4.33 ± 1.89 µg/g creatinine) were not statistically different from the BF + FF infants (5.81 ± 0.11 µg/g creatinine) (p > 0.05). The average daily BPA intake in EBF infants (0.18 ± 0.13 µg/kg body weight (bw)/day) was found to be significantly higher than in BF + FF infants (0.12 ± 0.09 µg/kg bw/day) (p < 0.05). The estimated dietary intakes of BPA for infants in both groups were below the temporary tolerable daily intake (t-TDI) (4 µg/kg bw/day). Consequently, BPA intake of EBF and BF + FF infants were within safe daily limits during the first six months of life.

Physiologically based modelling of dermal absorption and kinetics of consumer-relevant chemicals: A case study with exposure to bisphenol A from thermal paper

Bisphenol A (BPA) is one of the best studied industrial chemicals in terms of exposure, toxicity, and toxicokinetics. This renders it an ideal candidate to exploit the recent advancements in physiologically based pharmacokinetic (PBPK) modelling to support risk assessment of BPA specifically, and of other consumer-relevant hazardous chemicals in general. Using the exposure from thermal paper as a case scenario, this study employed the multi-phase multi-layer mechanistic dermal absorption (MPML MechDermA) model available in the Simcyp® Simulator to simulate the dermal toxicokinetics of BPA at local and systemic levels. Sensitivity analysis helped to identify physicochemical and physiological factors influencing the systemic exposure to BPA. The iterative modelling process was as follows: (i) development of compound files for BPA and its conjugates, (ii) setting-up of a PBPK model for intravenous administration, (iii) extension for oral administration, and (iv) extension for exposure via skin (i.e., hand) contact. A toxicokinetic study involving hand contact to BPA-containing paper was used for model refinement. Cumulative urinary excretion of total BPA had to be employed for dose reconstruction. PBPK model performance was verified using the observed serum BPA concentrations. The predicted distribution across the skin compartments revealed a depot of BPA in the stratum corneum (SC). These findings shed light on the role of the SC to act as temporary reservoir for lipophilic chemicals prior to systemic absorption, which inter alia is relevant for the interpretation of human biomonitoring data and for establishing the relationship between external and internal measures of exposure.

Assessment of BPA and BPS exposure in the general population in Guangzhou, China - Estimation of daily intakes based on urinary metabolites

Human exposure to bisphenol A (BPA) and bisphenol S (BPS) has garnered considerable global health concerns. In this paper, the daily intake (DI) of BPA and BPS in the general population of Guangzhou, China, were back-calculated using the biomarkers BPA glucuronides (BPA-G) and BPS glucuronides (BPS-G), respectively. The biomarkers are preferable to total BPA and BPS measurements because they are not susceptible to external contamination. A total of 1440 urine samples were gathered from the general population in Guangzhou, China, which were classified by age and sex into 36 pooled urine samples. 100% and 98% of pooled urine samples contained BPA-G and BPS-G at median values of 1.57 and 0.38 ng/mL, respectively. Based on urinary BPA-G and BPS-G concentrations, we determined the median DI of BPA and BPS to be 31.07 and 7.37 ng/(kg bw*d), respectively, and the highest values to be 106.77 ng/(kg bw*d) and 18.19 ng/(kg bw*d), respectively. Furthermore, our results showed that for the entire dataset, the DI of BPA and BPS were considerably greater in males than in females (p < 0.01)and declined significantly with age (p < 0.05). For risk assessment, the estimated DIs of BPA and BPS were much lower than the European Food Safety Authority’ s (EFSA) the temporary acceptable reference dose of 4 μg/(kg bw*d) advised for BPA, suggesting that the exposure risk of BPA and BPS for Guangzhou population is within a controllable safety range. This is the first study to investigate BPA and BPS exposure in the general population of Guangzhou, China, on the basis of urinary metabolites.

Associations of maternal urinary bisphenol and phthalate concentrations with offspring reproductive development

Fetal exposure to bisphenols and phthalates may influence development of the reproductive system. In a population-based, prospective cohort study of 1059 mother-child pairs, we examined the associations of maternal gestational urinary bisphenols and phthalates concentrations with offspring reproductive development from infancy until 13 years. We measured urinary bisphenol and phthalate concentrations in each trimester. We obtained information on cryptorchidism or hypospadias after birth from medical records. At 9.7 years, we measured testicular and ovarian volume by MRI. At 13.5 years, we measured child Tanner stages and menstruation through questionnaire. We performed linear or logistic regression models for boys and girls to assess the associations of maternal urinary average and trimester-specific bisphenols and phthalates with child reproductive outcomes. Next, to further explore potential synergistic or additive effects of exposures together, we performed mixed exposure models using a quantile g computation approach. Models were adjusted for maternal age, ethnicity, body-mass index, education, parity, energy intake, smoking and alcohol use, and child's gestational age at birth, birthweight and body-mass index. In boys, no associations of maternal gestational phthalate or bisphenol with offspring cryptorchidism and hypospadias were found. Higher maternal high-molecular-weight phthalate and total bisphenol, but not phthalic acid or low-molecular-weight phthalate, were associated with larger child testicular volume at 10 years. Higher maternal phthalic acid and total bisphenol were associated with earlier genital and pubic hair development at 13 years, respectively (p-values<0.05). In girls, we found no associations of maternal urinary bisphenol and phthalate with ovarian volume or menstrual age. Only higher maternal urinary high-molecular-weight phthalate was associated with earlier pubic hair development at 13 years (p-values <0.05). Higher mixture exposure was associated with earlier pubic hair development in both sexes. In conclusion, higher maternal gestational urinary bisphenol and phthalate concentrations were associated with alterations in offspring reproductive development, mainly in boys.

Bisphenol A in edible tissues of rams exposed to repeated low-level dietary dose by high-performance liquid chromatography with fluorescence detection

The presented work deals with levels and distribution of bisphenol A (BPA) in the edible tissues of a large food-producing animal species. An experimental animal study included 14 young Istrian pramenka rams (Ovis aries), of which seven were exposed for 64 days to a low dietary dose of BPA at 25 µg/kg b.w./day, and seven served as a control group. Residue analysis of both aglycone and total BPA was performed in the muscle tissue, liver, kidney and fat tissue of the individual animals by means of enzymatic deconjugation (for total BPA), organic solvent extraction, molecularly imprinted polymer solid-phase extraction (MISPE) clean-up and high-performance liquid chromatography with fluorescence detection (HPLC-FLU). The analysis was optimized and validated for aglycone BPA in the fat tissue and for the total BPA in all tissues investigated. Edible tissues of the control group of rams generally remained BPA-free, while there were concentration differences between the control and treated groups for liver and kidney post last administration. The human health risk resulting from this study was assessed by the estimated dietary exposure in adults, which was < 0.1% related to the valid European Union Tolerable Daily Intake (TDI) value of 4 µg/kg b.w./day. However, it would be 58-fold higher than the newly proposed TDI value of 0.04 ng/kg b.w./day.

Hollow fiber membrane-protected amino/hydroxyl bifunctional microporous organic network fiber for solid-phase microextraction of bisphenols A, F, S, and triclosan in breast milk and infant formula

Bisphenols and triclosan have been used in various products, and exposure to these chemicals may affect human health. The present study proposes a sensitive method for the determination of bisphenols A, F, S, and triclosan. The fiber was coated by amino/hydroxyl bifunctional microporous organic network and protected by polyvinylidene fluoride hollow fiber membrane for direct immersion solid phase microextraction. The limit of detection was 0.005 μg/L (μg/kg), and the recoveries were in the range of 76.7% to 107.5% (87.4% to 107.6%) for breast milk (infant formula), with intra-day and inter-day precisions <10.5% (7.3%) and 13.6% (8.4%), respectively. Fiber-to-fiber reproducibility of < 9.5% and a lifespan of >100 cycles were obtained. The 95th percentile estimated daily intake of total bisphenols was close to temporary tolerable daily intake for infants fed by human milk, which highlighted the needs for further attention on human exposure to BPA and its substitutes.

Bisphenol A correlates with fewer retrieved oocytes in women with tubal factor infertility

Serum and urinary bisphenol A (BPA) concentrations have been associated negatively with the number of retrieved oocytes after in vitro fertilization (IVF). The impact of BPA upon women with polycystic ovary syndrome (PCOS) and women with tubal factor infertility (TFI), following IVF, was investigated. To this purpose, associations among serum and urinary and follicular fluid (FF) BPA concentrations and the number of retrieved and fertilized oocytes and comparisons between pregnancy rates were evaluated. This was a cross-sectional study conducted at a university-affiliated assisted conception unit between January and November 2019, including 93 women of reproductive age (PCOS: 45; TFI: 48) following IVF. Unconjugated FF and serum BPA concentrations and total urinary BPA concentration were measured using a novel gas chromatography-mass spectrometry method. The number of retrieved and fertilized oocytes and pregnancy rate were documented and evaluated. The number of oocytes retrieved from PCOS women was greater than that of 21 TFI women, independently of BMI. Lower FF BPA concentrations were found in all PCOS women and in overweight/obese PCOS compared to TFI women (0.50, 0.38, and 1.13ng/mL, respectively). In TFI women, FF BPA concentrations correlated negatively with the number of retrieved oocytes. Serum and FF and urinary BPA concentrations did not significantly affect the number of fertilized oocytes and pregnancy rate in both groups. FF BPA concentrations were lower in all PCOS women and in overweight/obese PCOS than in TFI women. In TFI women, FF BPA concentrations correlated negatively with retrieved oocytes. Confirmation of these findings might lead to moderation of use of BPA-containing products by women undergoing IVF.

Basic Exploratory Study of Bisphenol A (BPA) Dietary Administration to Istrian Pramenka Rams and Male Toxicity Investigation.

Bisphenol A (BPA), an endocrine-disrupting chemical and environmental pollutant, has been reported by many researchers to induce male reproductive toxicity in different experimental models. In this study, we investigated whether long-term exposure for two months to 25 µg/kg body weight (low dose) of BPA affects spermatogenesis or sperm quality in young Istrian Pramenka rams exposed via diet. We evaluated body and testicular weights, histopathology of testes and epididymides, and sperm analyses, and compared these parameters between the group of treated rams and the control group of rams. Although there were some differences between the two groups, these differences were not large or statistically significant. The only statistically significant difference was the lower epithelial height of seminiferous tubules in treated rams, compared to control rams. In addition to assessing toxicity, BPA concentrations in the blood plasma of treated rams were determined after the first administration, and the toxicokinetic parameters of total BPA were calculated. In this study, no major signs of altered reproduction in rams were detected.