Evidence for Bisphenol B Endocrine Properties: Scientific and Regulatory Perspectives

Concentration and Variability of Urinary Phthalate Metabolites, Bisphenol A, Triclosan, and Parabens in Korean Mother–Infant Pairs

Concentrations of toxic chemicals in mothers highly correlate with those in their children; moreover, the levels are higher in children than in mothers. Non-persistent chemicals with a short half-life including phthalate metabolites, bisphenol A (BPA), triclosan (TCS), and parabens are metabolized and excreted through urine. Therefore, we assessed the urine concentrations of phthalate metabolites, BPA, TCS, and parabens; correlated the concentrations with exposure levels; and assessed the within-individual variability of these chemicals in mothers and their infants. We collected 225 and 71 samples from 45 mothers and 36 infants, respectively. For the variability analysis, 189 and 42 samples were collected from nine mothers and their infants, respectively. The median concentrations of phthalate metabolites in the mothers and infants were 0.53–26.2 and 0.81–61.8 μg/L, respectively, and those of BPA, TCS, and parabens were 0.24–76.3 and 2.06–12.5 μg/L, respectively. The concentrations of monoethyl phthalate (MEP), mono-N-butyl phthalate (MnBP), mono-isobutyl phthalate (MiBP), and BPA in the mothers were positively correlated with those in infants (0.45, 0.62, and 0.89, respectively; p < 0.05), whereas toxic chemical concentrations in infants were higher than those in the mothers. With respect to the within-individual intraclass correlation coefficient (ICC), the first morning void (FMV) of the mothers had high ICCs for all chemicals (range: 0.72–0.99), except for BPA, monobenzyl phthalate (MBzP), and monocarboxyoctyl phthalate (MCOP). The ICC values of most chemicals were moderate to high (range: 0.34–0.99) in the first morning void. However, there were different patterns of ICCs in the infants. These findings indicate the importance of mother–infant pair studies and the necessity of research in infants, as they have different exposure sources and pathways from adults.

Effects of Bisphenol A on expression of genes related to amino acid transporters, insulin- like growth factor, aquaporin and amino acid release by porcine trophectoderm cells

The peri-implantation period of pregnancy is critical for conceptus development, implantation, and signaling for establishment of pregnancy. This study evaluated the effects of bisphenol A (BPA) on proliferation, adhesion, and migration of porcine trophectoderm (pTr2) cells, expression of transporters of arginine and synthesis of amino acids. All concentrations of BPA decreased proliferation and adhesion of pTr2 cells after 96 h compared to the control group. Lower concentrations of BPA (1 × 10^-9, 1 × 10^-8, 10^-7M) increased (P < 0.05), but higher concentrations of BPA (1 × 10^-5, 1 × 10^-4 M) decreased migration of pTr2 cells. BPA increased expression of SLC7A1 mRNA at lower concentrations (1 × 10^-9 to 1 × 10^-6M) and SL7A6, another cationic acid transporter, at higher concentrations (1 × 10^-5, 1 × 10^-4 M). BPA also down-regulated the expression of IGF1 and IGF1 receptor at concentrations of 1 × 10^-7 to 1 × 10^-4 M compared to the control group. The expression of mRNAs for aquaporins (AQP) 3 and 4 were reduced at all concentrations of BPA, but at lower concentrations of BPA, (1 × 10^-9 to 1 × 10^-8M) expression of AQP9 mRNA increased and the expression of AQP11 was not affected by BPA (P > 0.05). There was an inhibitory effect of BPA on the release of synthesis of asparagine, threonine, taurine, tryptophan, and ornithine into the culture medium by pTr2 cells. Collectively, BPA adversely affected the expression of transporters for cationic amino acids like arginine, as well as AQPs, IGF1, and IGF1R associated with proliferation, migration, and adhesion of pTr2 cells. Those adverse effects would likely increase pregnancy losses during the peri-implantation period of pregnancy.

Exposure to New Emerging Bisphenols Among Young Children in Switzerland

Restrictions on the use of bisphenol A (BPA) in consumer products led to its replacement by various bisphenol (BP) analogues, yet young children's exposure to these analogues has been poorly characterized so far. This study aimed to characterize infants' and toddlers' exposure to BPA and 14 emerging BP analogues (i.e., bisphenol AF, bisphenol AP, bisphenol B, bisphenol BP, bisphenol C (BPC), bisphenol E, bisphenol F (BPF), bisphenol G, bisphenol M (BPM), bisphenol P, bisphenol PH, bisphenol S (BPS), bisphenol TMC, and bisphenol Z). We extracted infants' and toddlers' urine from diapers (n = 109) collected in Swiss daycare centers as a practical and noninvasive alternative approach to urinary biomonitoring. Bisphenols were present in 47% of the samples, with BPC and BPM being the most frequently detected (23% and 25% of all samples, respectively). The mean concentrations of urinary BPS and BPF were greater than that of BPA. This contrasts with data reported previously. Furthermore, statistical analysis revealed a significant and negative correlation between urinary BPM concentration and the population's age. Our results provide a first characterization of infants' and toddlers' exposure to bisphenols in Switzerland. This knowledge can be used to support ongoing biomonitoring studies and to prioritize exposure reduction and prevention strategies.

Associations of lifestyle factors with phthalate metabolites, bisphenol A, parabens, and triclosan concentrations in breast milk of Korean mothers

The toxicity of endocrine disruptors depends on the synergistic interactions of biological, environmental, and behavioral factors. The specific effects of diet, consumer product use, and behaviors, however, are debated in the literature, particularly with regard to endocrine disruptors found in breast milk. This study aimed to measure the levels of phthalate metabolites, bisphenol A, parabens, and triclosan in breast milk and to investigate their associations with various lifestyle factors. The breast milk samples as well as surveys were collected from 221 first-time mothers throughout South Korea and each sample was analyzed for the presence of 15 endocrine disruptors. Phthalate metabolites were detected in 5.4-83.3% of the samples, with median concentrations of 0.08-1.72 μg/L, while bisphenol A, parabens, and triclosan were detected in 25.8-88.2% of the samples, with median concentrations of 0.12-1.47 μg/L. High levels of endocrine disruptors were associated with frequent consumption of fish and cup noodles; the use of plastic and disposable food containers; the use of air fresheners, lotions and make-up; the purchase of new furniture; and socioeconomic status. We also observed the potential role of moderate walking activity on the reduction of these chemicals in breast milk. Our data provide evidence of the potential effects of diet, consumer products, and behavior on the presence of phthalate metabolites, bisphenol A, parabens, and triclosan in breast milk. Future studies should include community or regional impact on a mothers' exposure to endocrine disruptors, to assess the joint contribution of both individual and neighborhood factors.

Occurrence, trophic transfer, and health risk assessment of bisphenol analogues in seafood from the Persian Gulf

The presence of chemicals in marine organisms is an important issue for human health due to the growing rate of seafood consumption. Potential exposure to seven bisphenol analogues through seafood consumption was investigated in some popular seafood from the Persian Gulf. Bisphenols were analyzed by gas chromatography-mass spectrometry. Bisphenol A (BPA) and bisphenol B (BPB) were the first and second most common bisphenols in the studied samples, respectively. The highest levels of BPA (mean 13.58 ± 5.70 μg/kg.dw) and BPB (mean 10.30 ± 7.98 μg/kg.dw) were found in E.coioides species. Bisphenol F and bisphenol AF were detected only in P. armatus and L. klunzingeri, respectively. Trophic transfer investigation demonstrated that BPA and BPB were biomagnified in the studied organisms through their diet. The eco-toxicity and estrogenic risk assessment indicated that seafood consumption does not pose a health threat to consumers. However, routine monitoring of bisphenols in seafood seems to be necessary to ensure food safety.

Zeolitic imidazolate framework-8 coated Fe3O4@SiO2 composites for magnetic solid-phase extraction of bisphenols

A new magnetic composite material ZIF-8 coated Fe₃O₄@SiO₂ was employed for preconcentration and detection of trace BPs in water and plastic products.