Comparison of two derivatization-based methods for solid-phase microextraction–gas chromatography–mass spectrometric determination of bisphenol A, bisphenol S and biphenol migrated from food cans

Assessing dietary bisphenol A exposure among Koreans: comprehensive database construction and analysis using the Korea National Health and Nutrition Examination Survey

Bisphenol A (BPA) exposure primarily occurs through dietary intake. This study aimed to estimate the extent of dietary BPA exposure among Koreans. A thorough literature search was conducted to establish a BPA content database encompassing common foods consumed in Korea, including various food raw materials and processed food products. Dietary exposure levels were estimated by integrating the constructed BPA database with comprehensive nationwide 24 h-dietary recall datasets. The finding revealed that dietary BPA exposure was low for most Koreans, with a mean of 14.5 ng/kg bw/day, but was higher for preschool-age children (over 23 ng). Canned foods accounted for 9-36% of the total dietary exposure of the highest dietary exposure groups; while across all age groups, a considerable amount was derived from canned tuna, contribution of canned fruits and canned coffee (milk-containing) was high for preschool-age children and adults, respectively. Notably, for adults, a substantial proportion also stemmed from beer packaged in cans. While diet contributed over 80% of aggregate exposure for most age groups, preschool-age children experienced 60% exposure through diet due to additional exposure from indoor dust. Even at the high exposure scenario, aggregate BPA exposure levels remained lower than the current tolerable daily intake (TDI) set by the Korean agency (20 μg/kg bw/day). Nevertheless, most Koreans were exposed to BPA levels surpassing the strictest TDI (0.2 ng/kg bw/day) set by the European Food Safety Authority.

Optimization of a modified Captiva EMR-lipid method based on micro-matrix solid-phase dispersion coupled with gas chromatography-mass spectrometry for the determination of nine bisphenols in mussel samples

This work describes a reliable, cheap, easy and fast method for analysis of nine bisphenols in mussel samples by gas chromatography-mass spectrometry after trimethylsilylation. The modified method consisted of miniaturized matrix solid phase dispersion (micro-MSPD) in a glass Pasteur pipette using Captiva EMR (enhanced matrix removal)-lipid as the sorbent. Good linearity was obtained in the work range (1-500 μg L-1) with a correlation coefficient (R2) ≥ 0.998. The method accuracy and precision were determined at two concentration levels. The results show recoveries ranging from 55 to 111%. The precision varied from 1.95 to 11.4% (RSD). The whole quantification limits were between 0.056 and 3.42 μg per kg dry weight. The analytical procedure was applied for the analyses of five mussel samples collected from Galician Rias. The major compound was BPA, and wild mussels from Rías de Ferrol, Vigo and A Coruña had the highest levels. The proposed method is suitable for the analysis of BPA and its analogues in mussel samples.

Occurrence and exposure evaluation of bisphenol A and its analogues in indoor and outdoor dust from China

Bisphenol A (BPA) and its analogues have been proved to be harmful to human reproduction, endocrine and nervous system. But information on the occurrence and human exposure to bisphenol compounds (BPs) in dust (especially outdoor dust) is limited. In this study, 14 BPs were determined in 174 indoor dust samples and 202 outdoor dust samples from Chinese mainland, Hong Kong, Macau and Taiwan. BPA, BPS, BPAF, BPF, BPAP and BPE were widely detected with detection frequencies of 98.94 %, 98.67 %, 97.87 %, 95.21 %, 87.23 % and 71.54 %, respectively. The median total concentrations of the most detected six BPs in the dust were in the order of south urban indoors (556 ng/g) > south rural outdoors (438 ng/g) > south urban outdoors (432 ng/g) > south rural outdoors (418 ng/g) > north rural indoors (412 ng/g) > north urban outdoors (341 ng/g) > north urban indoors (311 ng/g) > north rural outdoors (246 ng/g). The amounts of garbage incineration, plastic output and recycled paper may have influence on the BPs levels. Some BPs (BPAF, BPAP, BPF and BPS) in the indoor and outdoor samples were significantly positively correlated. In addition, the BPs in the indoor dust from different indoor micro environments in Chengdu were investigated. BPA (median concentration: 571.2 ng/g) and BPF (median concentration: 114.3 ng/g) were the two primary BPs, accounting for 78.1 % of the median total concentrations of the investigated BPs. High concentration of BPA appeared in printing workshops and offices, while high concentration of BPAP, BPC, BPE and BPF appeared in electronic repair shops. Occupational exposure to BPs deserves attention in the future. ΣBPs exposure risk for children and adults in the urban areas of southern China was the highest. To our knowledge, this is the first report in China to study BPs in outdoor dust sample.

Biochemical responses and antioxidant defense mechanisms in Channa Striatus exposed to Bisphenol S

Bisphenol S (BPS), a BPA analog and a safer alternative, is utilized in a diverse range of industrial applications, such as making polycarbonate plastics, epoxy resins, thermal receipt papers, and currency bills. Recently, the increased use of BPS in containers and packages for daily life has been interrogated due to its identical chemical structure and probable endocrine-disrupting actions as BPA has. The present study aimed to evaluate the alterations in biochemical indices and antioxidant enzymes as certain indicators of the endocrine-disrupting effect of BPS in Channa striatus, a freshwater fish. BPS-exposed fish species were subjected to three sub-lethal concentrations of BPS (1, 4, and 12 ppm) and observed after an interval of 7 and 21 days. Exposure to BPS caused a reduction in the level of protein in muscle, gonads and the liver due to an impairment of protein synthesis. Levels of cholesterol in the muscle, gonads, and liver of BPS-exposed fish were found to be decreased after treatment, indicating either an inhibition of cholesterol biosynthesis in the liver or reduced absorption of dietary cholesterol. The levels of antioxidant enzymes such as superoxide dismutase, catalase, glutathione reductase and glutathione peroxidase showed remarkable increases, while the activity of glutathione S-transferase decreased considerably, indicating the antioxidant defense mechanism to counteract the oxidative stress induced by BPS. Moreover, a significant increase was noted in the level of lipid peroxidation products, like malondialdehyde and conjugate diene, which represent biomarkers of oxidative stress. The histoarchitecture changes were also observed in the liver, muscle and gonads of BPS-treated fish species. The present study showed that sub-lethal exposure to BPS significantly influenced the activities of these enzymes and peroxidation byproducts. From this study, it is concluded that BPS-caused toxic effects in fish species lead to an imbalance in the antioxidant defense system. It is clearly indicated that BPS toxicity could lead to susceptible oxidative stress in various tissues and could damage vital organs.

Simultaneous Quantification of 16 Bisphenol Analogues in Food Matrices

Exposure to bisphenol analogues can occur in several ways throughout the food production chain, with their presence at higher concentrations representing a risk to human health. This study aimed to develop effective analytical methods to simultaneously quantify BPA and fifteen bisphenol analogues (i.e., bisphenol AF, bisphenol AP, bisphenol B, bisphenol BP, bisphenol C, bisphenol E, bisphenol F, bisphenol G, bisphenol M, bisphenol P, bisphenol PH, bisphenol S, bisphenol Z, bisphenol TMC, and tetramethyl bisphenol F) present in canned foods and beverages. Samples of foods and beverages available in the Swiss and EU markets (n = 22), including canned pineapples, ravioli, and beer, were prepared and analyzed using QuEChERS GC-MS. The quantification method was compared to a QuEChERS LC-MS/MS analysis. This allowed for the selective and efficient simultaneous quantitative analysis of bisphenol analogues. Quantities of these analogues were present in 20 of the 22 samples tested, with the most frequent analytes at higher concentrations: BPA and BPS were discovered in 78% and 48% of cases, respectively. The study demonstrates the robustness of QuEChERS GC-MS for determining low quantities of bisphenol analogues in canned foods. However, further studies are necessary to achieve full knowledge of the extent of bisphenol contamination in the food production chain and its associated toxicity.

Prenatal bisphenol S exposure induces hepatic lipid deposition in male mice offspring through downregulation of adipose-derived exosomal miR-29a-3p

The increased usage of bisphenol S (BPS) results in wide distribution in pregnant women. In this study, pregnant mice were given multiple-dose BPS during gestation. Results showed that prenatal BPS exposure (50 μg/kg/day) induced increased weight gain, dyslipidemia, higher liver triglyceride (TG), adipocyte hypertrophy, and hepatic lipid deposition in male offspring. Exosomes play important roles in regulating lipid metabolism. Here, serum exosomes and adipose miRNA sequencing of male offspring indicated a remarkable decrease in miR-29a-3p expression. To clarify whether adipocyte-derived exosomes mediate hepatic lipid deposition, exosomes were extracted from BPS-treated adipocytes and co-cultured with hepatocytes. These exosomes could be taken up by hepatocytes and promoted lipid deposition, and notably, exosomal miR-29a-3p was downregulated. Furthermore, miR-29a-3p knockdown in adipocyte-derived exosomes promoted hepatocyte lipid deposition, whereas overexpression led to the opposite effect. Also, the role of miR-29a-3p was demonstrated in hepatocytes by overexpressing or knocking it down. Subsequent studies have shown that miR-29a-3p can promote lipid deposition by directly targeting Col4a1. Taken together, prenatal BPS exposure could lead to lower miR-29a-3p yield in adipocyte-derived exosomes and decrease miR-29a-3p content transported to hepatocytes, which further negatively regulate Col4a1 and promote hepatic lipid deposition. Our findings provided clues to maternal environmental exposure-induced liver metabolic diseases.

A review on immunomodulatory effects of BPA analogues

Bisphenol A (BPA) is a known endocrine disruptor found in many consumer products that humans come into contact with on a daily basis. Due to increasing concerns about the safety of BPA and the introduction of new legislation restricting its use, industry has responded by adopting new, less studied BPA analogues that have similar polymer-forming properties. Some BPA analogues have already been shown to exhibit effects similar to BPA, for example, contributing to endocrine disruption through agonistic or antagonistic behaviour at various nuclear receptors such as estrogen (ER), androgen (AR), glucocorticoid (GR), aryl hydrocarbon (AhR), and pregnane X receptor (PXR). Since the European Food Safety Authority (EFSA) issued a draft re-evaluation of BPA and drastically reduced the temporary tolerable daily intake (t-TDI) of BPA from 4 mg/kg body weight/day to 0.2 ng/kg body weight/day due to increasing concern about the toxic properties of BPA, including its potential to disrupt immune system processes, we conducted a comprehensive review of the immunomodulatory activity of environmentally abundant BPA analogues. The results of the review suggest that BPA analogues may affect both the innate and acquired immune systems and can contribute to various immune-mediated conditions such as hypersensitivity reactions, allergies, and disruption of the human microbiome.

Occurrence, distribution, and ecological risk of bisphenol analogues in marine ecosystem of urbanized coast and estuary

Bisphenol analogues are prevalent globally because of rampant usage and imprecise processing techniques, prompting alerts about environmental and health hazards. The method employed in this study by solid phase extraction (SPE) and liquid chromatography-tandem quadrupole mass spectrometer (LC-MS/MS) for both quantification and qualitative analysis of the bisphenol compounds in the surface water samples. The coastal and estuarine surface water of Port Dickson and Lukut ranges from 1.32 ng/L to 1890.51 ng/L of bisphenol analogues. BPF mean concentration at 1143.88 ng/L is the highest, followed by BPA and BPS at 59.01 ng/L and 10.96 ng/L, respectively. Based on RQm for bisphenol analogues, the highest for BPF at 2.49 (RQ > 1, high risk), followed by BPS at 0.12 (0.1 < RQ < 1, medium risk) and BPA at 0.09 (0.1 < RQ < 1, medium risk). The presence and current risk of bisphenols analogues should alert the possible water quality degradation soon.

Effects of endocrine disrupting compounds on female fertility

Endocrine Disrupting Compounds or Chemicals (EDCs) constitute an extensive and varied group of mostly non-natural chemicals that have the ability to imitate any aspect of hormone action, perturbing many physiological functions in humans and animals. As for female fertility, several EDCs are associated with adverse effects in the regulation of steroidogenesis, higher miscarriage rates as well as lower fertilization and embryo implantation rates and some of them are considered to decrease the number of high-quality embryos in assisted reproductive technology (ART) pregnancy. The most common EDCs are pesticides, hexachlorobenzene (HCB), hexachlorocyclohexane (HCH) and especially phthalates and bisphenols which are used in thousands of products as plasticizers. Among all, Bisphenol A (BPA) is one of the most permeating and well-studied EDCs. BPA's action resembles that of estradiol affecting negatively the female reproductive system in various ways. This review summarizes the most recent literature on the impact of EDCs in female fertility.

Bisphenol S induces oxidative stress-mediated impairment of testosterone synthesis by inhibiting the Nrf2/HO-1 signaling pathway

Bisphenol S (BPS) is an environmental endocrine disruptor widely used in industrial production. BPS induces oxidative stress and exhibits male reproductive toxicity in mice, but the mechanisms by which BPS impairs steroid hormone synthesis are not fully understood. Nuclear factor erythroid 2-related factor 2(Nrf2)/HO-1 signaling is a key pathway in improving cellular antioxidant defense capacities. Therefore, this study explored the effects of exposure to BPS on testosterone synthesis in adult male mice and its mechanisms with regard to the Nrf2/HO-1 signaling pathway. Adult male C57BL/6 mice were orally exposed to BPS (2, 20, and 200 mg/kg BW) with sesame oil as a vehicle (0.1 ml/10 g BW) per day for 28 consecutive days. The results showed that compared with the control group, serum testosterone levels were substantially reduced in the 20 and 200 mg/kg BPS treatment groups, and testicular testosterone levels were reduced in all BPS treatment groups. These changes were accompanied by a prominent decrease in the expression levels of testosterone synthesis-related enzymes (STAR, CYP11A1, CYP17A1, HSD3B1, and HSD17B3) in the mouse testis. In addition, BPS induced oxidative stress in the testis by upregulating the messenger RNA and protein levels of Keap1 and downregulating the levels of Nrf2, HO-1, and downstream antioxidant enzymes (CAT, SOD1, and Gpx4). In summary, our results indicate that exposure of adult male mice to BPS can inhibit Nrf2/HO-1 signaling and antioxidant enzyme activity, which induces oxidative stress and thereby may impair testosterone synthesis in testicular tissues, leading to reproductive damage.

Elucidation of Non-Intentionally Added Substances from Plant Fiber/Plastic Composites by UPLC-QTOF/MS

Plant fiber/plastic composites (PPCs) have been widely used in food contact materials (FCMs) for many benefits, such as their claimed better environmental footprint compared to conventional plastics. However, their safety is still not fully understood and must be comprehensively evaluated. Non-volatiles extracted from six PPCs with different plant fibers and polymer matrices were characterized by employing ultra-high-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry in combination with various spectral libraries and manual elucidation, taking into account spectral similarity and characteristic product ions. A total of 115 compounds were tentatively identified, 50 of which were oligomers or their derivatives from the sample with polylactic acid (PLA) and polybutylene adipate terephthalate (PBAT) as the polymer matrix, and some of them were Cramer rules class III substances based on the threshold of toxicological concern (TTC). Seven reaction products between PLA and PBAT monomers, as well as four derivatives of melamine, were elucidated and well detailed for the first time. In addition, bisphenol S was detected in all samples even though its origin remains to be further explored. Isoprothiolane, as an insecticide and fungicide used to control a range of rice pests, was identified in the sample with rice husk as fillers, experimentally confirming the presence of agrochemicals in samples containing plant fibers.

Exploring bisphenol S removal mechanism with multi-enzymes extracted from waste sludge and reed sediment

4,4'-Sulfonyl-diphenol (BPS), as a widespread environmental hormone-like micropollutant, is difficult to be degraded in the environment. In this study, the removal of BPS with multi-enzymes extracted from waste sludge and reed sediment was studied at 298 K, 310 K, and 328 K. Results show that BPS could be removed efficiently and was time-temperature dependent, which could involve enzymolysis and bio-flocculation. The mechanism and pathways of the enzymolysis were identified with ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Polymerization of BPS with enzymolysis further improved the removal by bio-flocculation due to the production of BPS oligomers. Furthermore, the interaction mechanism between BPS and multi-enzyme was explored through a series of spectroscopic experiments. Results show that more loose skeletal structure of the multi-enzymes and more hydrophobic microenvironment of the amino acid residues are responsible for the removal of BPS. This research not only provided a method for refractory micropollutants removal but also a way for the utilization of waste sludge and reed sediment.

Aptamer-functionalised metal-organic frameworks as an 'on-off-on' fluorescent sensor for bisphenol S detection

Bisphenol S (BPS) is an industrial chemical that is widely used to manufacture daily items, such as plastic water bottles, milk bottles, water cups, and paper products. BPS is a biologically toxic environmental endocrine disruptor. Long-term exposure to BPS can disrupt the reproductive system, endanger health, and increase the risk of cancer. The metal-organic framework UiO-66 is characterised with high thermal and chemical stability, a simple synthetic route, and low preparation cost. In this study, we modified UiO-66 with nucleic acid aptamers to prepare an 'on-off-on' fluorescent sensor for the simple and rapid detection of BPS. The FAM-labelled aptamer was selected as the fluorescent probe (i.e. 'on'). In the presence of UiO-66, the FAM-labelled aptamer adsorbed onto the surface of the UiO-66 material, and the fluorescence of FAM was quenched by photoinduced electron transfer (i.e. 'off'). When BPS was introduced into the system, the configuration of the FAM-labelled aptamer changed after binding to BPS, and the adsorption of FAM on UiO-66 weakened, resulting in fluorescence recovery (i.e. 'on'). Based on this principle, the reaction system was optimised, and the BPS content was analysed according to the change in the fluorescence signal. The signals changed linearly in the BPS concentration range of 2.0 × 10^-4-4.0 × 10^-2 mmol L^-1, and the system had a detection limit of 1.84 × 10^-4 mmol L^-1. The sensor was successfully used to detect the BPS content in commercial plastic bottled water.

An overview of the occurrence, fate, and human risks of the bisphenol-A present in plastic materials, components, and products

With over 95% of bisphenol-A (BPA) used in the production of polycarbonate (PC) and epoxy resins, termed here as BPA-based plastic materials, components, and products (MCPs), an investigation of human exposure to BPA over the whole lifecycle of BPA-based plastic MCPs is necessary. This mini-review unpacks the implications arising from the long-term human exposure to BPA and its potential accumulation across the lifecycle of BPA-based plastics (production, use, and management). This investigation is timely and necessary in promoting a sustainable circular economy model. Restrictions of BPA in the form of bans and safety standards are often specific to products, while safety limits rely on traditional toxicological and biomonitoring methods that may underestimate human health implications and therefore the "safety" of BPA exposure. Controversies in regards to the: (a) dose-response curves; (b) the complexity of sources, release mechanisms, and pathways of exposure; and/or (c) the quality and reliability of toxicological studies, appear to currently stifle progress toward the regulation of BPA-based plastic MCPs. Due to the abundance of BPA in our MCPs production, consumption, and management systems, there is partial and inadequate evidence on the contribution of BPA-based plastic MCPs to human exposure to BPA. Yet, the production, use, and end-of-life management of plastic MCPs constitute the most critical BPA source and potential exposure pathways that require further investigation. Active collaboration among risk assessors, government, policy-makers, and researchers is needed to explore the impacts of BPA in the long term and introduce restrictions to BPA-based MCPs. Integr Environ Assess Manag 2023;19:45-62. © 2022 SETAC.

The Caenorhabditis elegans cuticle plays an important role against toxicity to bisphenol A and bisphenol S

Caenorhabditis elegans represents a favorite non-mammalian animal model, which is often used to study the effect of foreign substances on living organisms. Its epidermal barrier is a primary biological barrier that protects nematodes from the toxicity of chemicals. In this study, we investigated the effect of Bisphenol A (BPA), an endocrine disrupting chemical, and its structural analog Bisphenol S (BPS), which is often used as a substitute for BPA in some products, on the behavior of C. elegans wild type (N2) and C. elegans bli-1 mutant strain, which is characterized by the production of abnormal cuticle blisters. We found that exposure of C. elegans wild type (N2), as well as its mutant strain bli-1, to selected concentrations of BPA (0.1, 0.5, 1 and 5 µM) and BPS (0.1, 0.5, 1 and 5 µM) resulted in significant changes in reproduction, habituation behavior, and body length of nematodes. Based on our findings, we can conclude that BPS, which was supposed to be a safer alternative to BPA, caused almost identical detrimental effects on C. elegans behavior. Furthermore, compared to the wild type of C. elegans, these effects were more pronounced in the bli-1 strain, which is characterized by a mutation in an individual collagen gene responsible for proper cuticle formation, underlying the role of the epidermal barrier in bisphenol toxicity. Taken together, our data indicate the potential risks of using BPS as a BPA alternative.

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

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

USAEME-GC/MS Method for Easy and Sensitive Determination of Nine Bisphenol Analogues in Water and Wastewater

A new, simple and sensitive method for isolating nine compounds from the bisphenol group (analogues: A, B, C, E, F, G, Cl₂, Z, AP) based on one-step liquid-liquid microextraction with in situ acylation followed by gas chromatography-mass spectrometry was developed and validated using influent and effluent wastewaters. The chemometric approach based on the Taguchi method was used to optimize the main conditions of simultaneous extraction and derivatization. The recoveries of the proposed procedure ranged from 85 to 122%, and the repeatability expressed by the coefficient of variation did not exceed 8%. The method's limits of detection were in the range of 0.4-64 ng/L, and the method's limits of quantification ranged from 1.3 to 194 ng/L. The developed method was used to determine the presence of the tested compounds in wastewater from a municipal wastewater treatment plant located in northeastern Poland. From this sample, eight analytes were detected. Concentrations of bisphenol A of 400 ng/L in influent and 100 ng/L in effluent were recorded, whereas other bisphenols reached 67 and 50 ng/L for influent and effluent, respectively. The removal efficiency of bisphenol analogues in the tested wastewater treatment plant ranged from 7 to approximately 88%.

Diet quality and exposure to endocrine-disrupting chemicals among US adults

Human exposure to endocrine-disrupting chemicals (EDCs) may increase risk for chronic disease. Diet is a significant source of EDC exposure, yet healthy diets recommended for chronic disease prevention have not been thoroughly examined for associations with EDC exposure. Using data from the National Health and Nutrition Examination Survey 2013-2016, we examined associations of dietary patterns with exposure to non-persistent EDCs potentially consumed through diet. EDCs were measured in spot urine samples. Diet was assessed using 24-h recalls. Multivariable linear regression was used to examine associations of three healthy diet scores [Healthy Eating Index (HEI), relative Mediterranean Diet (rMED), and Dietary Approaches to Stop Hypertension] and fast-food consumption with EDCs. In fully adjusted models, no diet was associated with exposure to the bisphenols, phthalates, or polycyclic aromatic hydrocarbons examined. A 1-point increase in rMED (of 18 possible points) was associated with 2.7% (95% CI: 1.7%, 3.8%) greater urinary nitrate. A 10-point increase in HEI (of 100 possible points) was associated with 5.3% (95% CI: 2.8%, 7.9%) greater nitrate and 6.8% (95% CI: 4.5%, 9.2%) greater perchlorate. Because perchlorate and nitrate can disrupt thyroid hormone production, we conducted an exploratory analysis to examine whether these chemicals mediate an association between diet and thyroid hormones. A 10-point increase in HEI was associated with 0.6% reduced serum total thyroxine (95% CI: 1.7%, 0.5%) among all adults, with 57.5% of the effect explained by perchlorate. Nitrate mediated an association of rMED with modestly reduced total triiodothyronine among females. Most EDCs examined had no association with the diets evaluated, indicating that recommended healthy diets were not protective against EDC exposures. As observed with two thyroid antagonists, some recommended diets may increase EDC exposures and related adverse health outcomes. Additional work should identify effective food production and processing practices to reduce dietary exposures to potentially harmful EDCs.

A study on bisphenol S induced nephrotoxicity and assessment of altered downstream kidney metabolites using gas chromatography-mass spectrometry based metabolomics

The global use of bisphenol S (BPS) has now been significantly increased for commensurate utilization as a substitute for BPA for its regulatory concerns. Though, previous reports indicated that BPS been also appeared as a toxic congener comparable to BPA. In the present study, we determined nephrotoxicity condition induced due to BPS exposure. Results indicated that BPS significantly promoted histopathological disturbance in the kidney, and altered the levels of biomarkers of kidney damage in serum and urine samples of Wistar rats. It is also indicated that BPS altered the expression of kidney damage biomarkers associated with glomerular and tubular injury. Additionally, we determined the perturbation of kidney metabolites in the underlying pathophysiological response of kidney injury due to BPS exposure. Gas chromatography-mass spectrometry based untargeted metabolomics exhibited 20 significantly perturbed metabolites. Moreover, metabolic pathway analysis revealed significant disturbance in the TCA cycle and pyruvate metabolism pathways.

Bisphenols induce human genomic damage and modulate HERVs/env expression

Bisphenol A (BPA), a recognized endocrine-disrupting chemical, is used in the production of epoxy and polycarbonate resins. Since human exposure to BPA has been associated with increased cancer susceptibility, the market has shifted to products often labeled as "BPA free" containing BPA analogs such as bisphenol F (BPF) and bisphenol S (BPS). However, the European legislation on BPF and BPS is still unclear. This study analyzed the effects of BPA, BPF, and BPS exposure on human peripheral blood mononuclear cells by using in vitro micronucleus assay. Furthermore, it investigated the impact of bisphenols exposure on human endogenous retroviruses (HERVs) expression, which is implicated with the pathogenesis of several human diseases. The micronucleus assay revealed a significant genotoxic effect in peripheral blood cells after exposure to BPA and BPF at concentrations of 0.1, 0.05, and 0.025 μg/ml, and to BPS at 0.1 and 0.05 μg/ml. In addition, BPA exposure seems to upregulate the expression of HERVs, while a downregulation was observed after BPF and BPS treatments. Overall, our data showed the toxic effect of BPA and its analogs on circulating cells in the blood and demonstrated that they could modulate the HERVs expression.

Human Biomonitoring Guidance Values (HBM-GVs) for Bisphenol S and Assessment of the Risk Due to the Exposure to Bisphenols A and S, in Europe

Within the European Joint Programme HBM4EU, Human Biomonitoring Guidance Values (HBM-GVs) were derived for several prioritised substances. In this paper, the derivation of HBM-GVs for the general population (HBM-GVGenPop) and workers (HBM-GVworker) referring to bisphenol S (BPS) is presented. For the general population, this resulted in an estimation of the total urinary concentration of BPS of 1.0 µg/L assuming a 24 h continuous exposure to BPS. For workers, the modelling was refined in order to reflect continuous exposure during the working day, leading to a total urinary concentration of BPS of 3.0 µg/L. The usefulness for risk assessment of the HBM-GVs derived for BPS and bisphenol A (BPA) is illustrated. Risk Characterisation Ratios (RCRs) were calculated leading to a clear difference between risk assessments performed for both bisphenols, with a very low RCR regarding exposure to BPA., contrary to that obtained for BPS. This may be due to the endocrine mediated endpoints selected to derive the HBM-GVs for BPS, whereas the values calculated for BPA are based on the temporary Tolerable Daily Intake (t-TDI) from EFSA set in 2015. A comparison with the revised TDI recently opened for comments by EFSA is also discussed. Regarding the occupational field, results indicate that the risk from occupational exposure to both bisphenols cannot be disregarded.

Targeted screening of 11 bisphenols and 7 plasticizers in food composites from Canada and South Africa

A sensitive method based on ultrasound-assisted liquid extraction coupled with liquid chromatography was applied to screen 18 plastic-related contaminants in 168 food composites (namely fish fillets, chicken breast, canned tuna, leafy vegetables, bread and butter) collected in Montreal (Canada), Pretoria and Vhembe (South Africa). Bisphenol A (BPA), bisphenol S (BPS) and seven plasticizers (di-n-butyl phthalate (DBP), diethyl phthalate (DEP), (2-ethylhexyl) phthalate (DEHP), di-(2-ethylhexyl) adipate (DEHA), di-isononyl phthalate (DINP), di-(isononyl)-cyclohexane-1,2-dicarboxylate (DINCH)) were detected in different foods from both countries. DBP and DEP were the most frequently detected contaminants in food collected in Montreal (75% for both) and DINP was the most frequently detected contaminant in food from South Africa (67%). DEHA concentration in packaged fish were significantly higher than the values for non-packaged fish (p < 0.01) suggesting that the packaging film can be one source of DEHA in fish.

Estimation of parabens and bisphenols in maternal products and urinary concentrations in Indian pregnant women: daily intake and health risk assessment

The presence of parabens and bisphenols in maternal products and usage during pregnancy have raised serious concern about their possible harm to pregnant women. The concentrations of six parabens and eight bisphenols were quantified by high-performance liquid chromatography-tandem mass spectrometry in the samples of commercially available herbal-based ayurvedic maternal products and urine of healthy pregnant women from Assam, India. Methyl paraben (MP) and bisphenol AF (BPAF) were found to be more dominant in the maternal products, whereas MP, bisphenol A (BPA), and BPAF were dominant in urine samples of healthy pregnant women. The sum of the mean concentrations of all forms of parabens and bisphenols in maternal products were 48,308.50 ng/g and 542.42 ng/g, respectively, and urine 101.33 ng/mL and 23.42 ng/mL, respectively. The estimated daily intake (EDI) of total parabens and bisphenols in maternal products were 7378.02 and 19.78 ng/kg body weight/day, respectively. EDI of total parabens and bisphenols from urinary concentrations were 690.12 and 111.33 μg/kg body weight/day, respectively. The concentrations of butyl (BP) and heptyl (HP) parabens have a significant positive correlation with birth weight. The hazard quotient (HQ) value of MP, EP, and BPA was less than 1, and margin of exposure (MOE) identified potential risk associated with propyl paraben. Results from Monte-Carlo risk assessment analysis did not exceed the acceptable daily intake (ADI). Our results showed that higher concentrations of parabens and bisphenols are present in maternal products and the urine of healthy pregnant women. Hence maternal products containing bisphenols and parabens should be used cautiously during pregnancy to avoid maternal and fetal complications.

Nursing Exposure to Bisphenols as a Cause of Male Idiopathic Infertility

Idiopathic infertility is a serious problem, which can be caused and explained by exposure to endocrine disruptors, such as bisphenols. In our study, we studied transactional exposure to bisphenol and its effects on newborn male mice throughout their reproductive life. Newborn male mice were exposed to bisphenol S and bisphenol F through maternal milk from post-natal day 0 to post-natal day 15 at concentrations of 0.1 ng.g/bw/day and 10 ng.g/bw/day, respectively. Although there were minimal differences between the control and experimental groups in testicular tissue quality and spermatozoa quality, we discovered an interesting influence on early embryonic development. Moderate doses of bisphenol negatively affected cleavage of the early embryo and subsequently, the blastocyst rate, as well as the number of blastomeres per blastocyst. In our study, we focused on correlations between particular stages from spermatogenesis to blastocyst development. We followed epigenetic changes such as dimethylation of histone H3 and phosphorylation of histone H2 from germ cells to blastocysts; we discovered the transfer of DNA double-strand breaks through the paternal pronucleus from spermatozoa to blastomeres in the blastocyst. We elucidated the impact of sperm DNA damage on early embryonic development, and our results indicate that idiopathic infertility in adulthood may have causes related to the perinatal period.

Chemical contaminants in canned food and can-packaged food: a review

Canning, as a preservation technique, is widely used to extend the shelf life as well as to maintain the quality of perishable foods. During the canning process, most of the microorganisms are killed, reducing their impact on food quality and safety. However, the presence of a range of undesirable chemical contaminants has been reported in canned foods and in relation to the canning process. The present review provides an overview of these chemical contaminants, including metals, polymeric contaminants and biogenic amine contaminants. They have various origins, including migration from the can materials, formation during the canning process, or contamination during steps required prior to canning (e.g. the disinfection step). Some other can-packaged foods (e.g. beverages or milk powder), which are not canned foods by definition, were also discussed in this review, as they have been frequently studied simultaneously with canned foods in terms of contamination. The occurrence of these contaminants, the analytical techniques involved, and the factors influencing the presence of these contaminants in canned food and can-packaged food are summarized and discussed.

Assessment of the Effective Impact of Bisphenols on Mitochondrial Activity, Viability and Steroidogenesis in a Dose-Dependency in Human Adrenocortical Carcinoma Cells

In recent years, bisphenol analogues such as bisphenol B (BPB), bisphenol F (BPF), and bisphenol S (BPS) have come to replace bisphenol A (BPA) in food packaging and food containers, since BPA has been shown to leach into food and water, causing numerous negative health effects. Although much information on the endocrine activity of BPA is available, a proper human hazard assessment of analogues that are believed to have a less harmful toxicity profile is lacking. The aim of our in vitro study was to assess the potential effect of bisphenol B, F, and S on the biosynthesis of steroid hormones in human H295R adrenocortical carcinoma cells, using the enzyme-linked immunosorbent assay. In addition, we evaluated mitochondrial activity using the MTT test and viability using triple assay. Adrenocortical carcinoma cells were cultivated for 24 h in the presence of bisphenol B, F, or S (0.1, 0.5, 1, 10, 25, 50, 75, 100 μM). We demonstrated that BPB, BPF, and BPS could affect progesterone and testosterone secretion, as well as affect cell mitochondrial, lysosomal, and metabolic activity, as well as plasma membrane integrity, but considerably more detailed and systematic research is required for a better understanding of risks associated with the effects of bisphenols on steroidogenesis.

Development of a Lateral Flow Immunoassay (LFIA) to Screen for the Release of the Endocrine Disruptor Bisphenol A from Polymer Materials and Products

One of the most important chemicals used in the production of polymer plastics and coatings is bisphenol A. However, despite the large number of studies on the toxicity and hormonal activity of BPA, there are still open questions and thus considerable media attention regarding BPA toxicity. Hence, it is necessary to develop a sensitive, simple, cost-efficient, specific, portable, and rapid method for monitoring bisphenol A and for high sample throughput and on-site screening analysis. Lateral flow immunoassays have potential as rapid tests for on-site screening. To meet sensitivity criteria, they must be carefully optimized. A latex microparticle-based LFIA for detection of BPA was developed. The sensitivity of the assay was improved by non-contact printing of spot grids as the control and test lines with careful parameter optimization. Results of the test could be visually evaluated within 10 min with a visual cut-off of 10 µg/L (vLOD). Alternatively, photographs were taken, and image analysis performed to set up a calibration, which allowed for a calculated limit of detection (cLOD) of 0.14 µg/L. The method was validated for thermal paper samples against ELISA and LC-MS/MS as reference methods, showing good agreement with both methods.

Effects of bisphenols on Blood-Testis Barrier protein expression in vitro: A systematic review and meta-analysis

Bisphenols are a group of environmental endocrine-disrupting chemicals that produce alterations in the expression of intercellular junction proteins of the Blood-Testis Barrier (BTB) involved in spermatogenesis. The association between bisphenol exposure and BTB protein expression is controversial. Therefore, we performed this systematic review and meta-analysis to clarify bisphenol effects on Sertoli cell BTB protein expression in vitro. The Standardized Mean Difference (SMD) with a 95 % confidence interval (95 % CI) was used to evaluate the association between alterations in the BTB protein expression and bisphenol exposure in vitro. Six articles were included in the meta-analysis. Bisphenol-A (BPA) exposure at 200 μM was associated with significant decrease in BTB protein expression (SMD = -2.70, 95 %CI: -3.59, -1.80, p het = 0.46, p = <0.00001). In the moderate (40-50 μM) and low dose (<25 μM), no significant associations were obtained. We also found a non-monotonic dose-response curve of bisphenol effect in ZO-1 protein expression; low and high doses presented a significant decrease compared to control, while moderate dose presented no change. The current temporary Tolerable Daily Intake (tTDI) of BPA is 4 μg/kg bw/day. The 5-25 μM doses of BPA are equivalent to ∼1-5 mg/kg bw, respectively. Although the low dose group (<25 μM) assessed doses below the previous NOAEL value, these doses are above the current tTDI. Thus, it is necessary to conduct more studies with lower bisphenol concentrations to avoid underestimating the potential adverse effects of bisphenols at doses below tTDI.

Oxidative stress responses of a freshwater fish, Labeo rohita, to a xenobiotic, bisphenol S

Bisphenol S (BPS) is an organic chemical that has been used as a substitute for bisphenol A (BPA) in making polycarbonate plastics, epoxy resins, thermal receipt papers, and currency bills, as BPA has been reported to have dreadful effects on the living system. From this view point, the present study investigates whether BPS has the same or rather more toxic effects like BPA or not. Limited studies were carried out on the effect of BPS on fish. The hepatic antioxidant enzymes such as superoxide dismutase, catalase, glutathione S-transferase, glutathione reductase, and glutathione peroxidase (GPx), along with the nonenzymatic antioxidant, glutathione, in a freshwater fish, Labeo rohita, were selected as biomarkers. The results revealed that the sublethal exposure of BPS significantly influenced the activities of these biomarkers. Lipid peroxidation (LPO) products such as malondialdehyde and conjugate diene levels were also altered by the exposure. The alteration in the levels of antioxidants and LPO products after BPS exposure clearly showed that the fish experienced oxidative stress. Furthermore, the current study showed that BPS is a pollutant with oxidative potential by disrupting the antioxidant enzymes.

Occurrence of Free-Form and Conjugated Bisphenol Analogues in Marine Organisms

Upon exposure, most bisphenol analogues (BPs) are rapidly metabolized to BP conjugates in organisms. Monitoring studies on BPs in aquatic organisms have been mainly focused on free-form BPs. However, the relative amount of conjugated BPs in organisms is still not well known, especially in marine organisms. In this study, we collected marine organisms (13 species; n = 74), as well as seawater (n = 15), from East China Sea, and analyzed them for bisphenol A (BPA) and its eight analogues. In seawater, BPA was the predominant BP (mean ± standard deviation (SD), 18 ± 9.7 ng/L), followed by bisphenol S (BPS; 3.7 ± 2.8 ng/L), bisphenol F (BPF; 0.31 ± 0.17 ng/L), and bisphenol AF (BPAF; 0.24 ± 0.15 ng/L). The whole body of each marine organism was used for BP analysis in this study. BPA (mean 3.8 ng/g, range 1.2-7.7 ng/g) and BPS (1.5 ng/g, 0.19-6.1 ng/g) were still the predominant BPs in marine organisms without hydrolysis. After enzymatic hydrolysis treatment, mean concentrations of BPs increased 1.8 (BPS)-3.7 (BPA) times in marine organisms. Correspondingly, on average, 74, 52, 49, 48, and 45% of BPA, bisphenol Z, BPF, BPS, and BPAF were present in conjugated forms, respectively, in marine organisms. Moreover, bioaccumulation and biomagnification of BPs were evaluated using pooled marine organism samples. We first found that the mean log BAF values of BPs increased 0.091 (BPAF) to 0.31 (BPA) times in marine organisms after hydrolysis. Overall, this study first determines the amount of BPs present in conjugated forms in marine organisms, which are helpful for better understanding the occurrence of BPs in organisms.

A sensitive and fast approach for voltammetric analysis of bisphenol a as a toxic compound in food products using a Pt-SWCNTs/ionic liquid modified sensor

A sensitive and fast approach has been introduced for the voltammetric sensing of bisphenol A based on modification of a paste electrode with Pt-SWCNTs and 1-ethyl-3-methylimidazolium n-butylsulfate as a highly conductive binder. The new sensor was used to determine the concentration of bisphenol A in food products in I-V mode. The Pt-SWCNTs nanocomposite was synthesized through the polyol method and its morphology was evaluated by field emission scanning electron microscopy, transmission electron microscopy and energy-dispersive X-ray spectroscopy techniques. The determining factors influencing the sensing performance, i.e., pH and mediators used in the modification process were optimized in the first step and the results showed that at a pH of 7.0, a modified paste containing 9% (w:w) nanocomposite and 20% (v:v) 1-ethyl-3-methylimidazolium n-butylsulfate formed catalytic properties enhancing the oxidation signal of bisphenol A by 5.9 folds. Current density investigation clearly confirmed the conductivity of Pt-SWCNTs and 1-ethyl-3-methylimidazolium n-butylsulfate in the paste matrix. In addition, fabricated sensor showed considerable sensing behavior for bisphenol A in the concentration range of 0.5 nM-180 μM with a detection limit of 0.2 nM. In the final step, using standard addition technique, the ability of fabricated sensor for sensing bisphenol A in food products was evaluated, and the results confirmed improved performance of the modified electrodes.

Bisphenol A and Bisphenol S Induce Endocrine and Chromosomal Alterations in Brown Trout

Bisphenol A is a widely used compound found in large amount of consumer products. As concerns have been raised about its toxicological and public health effect, the use of alternatives to bisphenol A are now increasing. Bisphenol S is one of the analogues being used as a replacement for bisphenol A despite the fact that little is known about the effects of bisphenol S on living organisms. In this study, we investigated the potential endocrine and genotoxic effects of bisphenol A and bisphenol S in juvenile brown trout (Salmo trutta). The fish were exposed to the compounds for either 2 weeks or 8 weeks via sustained-release cholesterol implants containing doses of 2 mg/kg fish or 20 mg/kg fish of the substances. The effects on the thyroid hormone levels and the estrogenic disrupting marker vitellogenin were evaluated, along with the genotoxic markers micronucleated cells and erythrocyte nuclear abnormalities. An increase in plasma vitellogenin was observed in fish exposed to the high dose of bisphenol A for 2 weeks. At this experimental time the level of the thyroid hormone triiodothyronine (T3) in plasma was elevated after bisphenol S exposure at the high concentration, and paralleled by an increase of micronucleated cells. Moreover, bisphenol A induced an increase of micronuclei frequency in fish erythrocytes after the exposure at the lowest dose tested. Taken together the results indicate that both bisphenol A and its alternative bisphenol S cause endocrine disrupting and genotoxic effects in brown trout, although suggesting two different mechanisms of damage underlying bisphenol A and bisphenol S activity.

Toxicity and biotransformation of bisphenol S in freshwater green alga Chlorella vulgaris

Safety and environmental behavior of bisphenol A (BPA) alternatives have attracted considerable attention because of their wide use. In the present study, toxicity and biotransformation of bisphenol S (BPS), a primary alternative to BPA, in Chlorella vulgaris were investigated. BPS had a significant inhibition on the growth rate of C. vulgaris with an inhibition rate of 41.6%, 103.7% and 238.4% under exposure of 1, 10 and 100 mg L^-1 BPS, respectively. BPS (2 d EC₅₀: 3.16 mg L^-1) had a higher acute toxicity to C. vulgaris than BPA (2 d EC₅₀: 41.43 mg L^-1), but its toxicity was gradually lower than BPA as the exposure time increased. BPS underwent rapid degradation and was more recalcitrant to degradation by C. vulgaris than BPA at 5 and 10 mg L^-1. BPS was less accumulated in algal cells than BPA (p < 0.05), suggesting that it may pose less risk than BPA on the aquatic algophagous organisms and other high-trophic-level predators through the food chain. In addition, six new metabolites of BPS were identified in algal cells using high-resolution mass spectrometry. This is the first time that degradation pathway for BPS in algae is described, and these results represent a significant advance in understanding the fate of BPS and other BPA substitutes in the aquatic environment.

A comprehensive review of the neurobehavioral effects of bisphenol S and the mechanisms of action: New insights from in vitro and in vivo models

The normal brain development and function are delicately driven by an ever-changing milieu of steroid hormones arising from fetal, placental, and maternal origins. This reliance on the neuroendocrine system sets the stage for the exquisite sensitivity of the central nervous system to the adverse effects of endocrine-disrupting chemicals (EDCs). Bisphenol A (BPA) is one of the most common EDCs which has been a particular focus of environmental concern for decades due to its widespread nature and formidable threat to human and animal health. The heightened regulatory actions and the scientific and public concern over the adverse health effects of BPA have led to its replacement with a suite of structurally similar but less known alternative chemicals. Bisphenol S (BPS) is the main substitute for BPA that is increasingly being used in a wide array of consumer and industrial products. Although it was considered to be a safe BPA alternative, mounting evidence points to the deleterious effects of BPS on a wide range of neuroendocrine functions in animals. In addition to its reproductive toxicity, recent experimental efforts indicate that BPS has a considerable potential to induce neurotoxicity and behavioral dysfunction. This review analyzes the current state of knowledge regarding the neurobehavioral effects of BPS and discusses its potential mode of actions on several aspects of the neuroendocrine system. We summarize the role of certain hormones and their signaling pathways in the regulation of brain and behavior and discuss how BPS induces neurotoxicity through interactions with these pathways. Finally, we review potential links between BPS exposure and aberrant neurobehavioral functions in animals and identify key knowledge gaps and hypotheses for future research.

Fate of bisphenol S (BPS) and characterization of non-extractable residues in soil: Insights into persistence of BPS

The environmental fate and persistence of bisphenol S (BPS), a substitute for bisphenol A (BPA), are unclear. This study used ¹⁴C-labeled BPS to examine the fate, biodegradation, and residue properties of BPS incubated in an oxic soil for 28 days. BPS dissipated quickly, with a half-life of 2.8 days. Most of the BPS was mineralized (53.6 ± 0.2% of initial amount by day 28) or transformed into non-extractable residues (NERs) (45.1 ± 0.3%), with generation of minor extractable residues (3.7 ± 0.2%) containing two metabolites. NERs were formed mainly via physico-chemical entrapment (51.1 ± 2.4% of the total NERs, consisting almost exclusively of BPS) and ester-linkages (31.5 ± 3.0% of the total NERs, consisting of both BPS and polar metabolites). When mixed with fresh soil, BPS-derived NERs became unstable and bioavailable. Subsequent mineralization was determined for 19.5 ± 1.1% of the total NERs and 35.5 ± 2.6% of the physico-chemically entrapped BPS. A fate model was used to describe the kinetics of NER formation, which indicated that microbial activity in soil could have strongly reduced the kinetic rate of the release of physico-chemically entrapped NERs into free form and therefore increased the stability of this type of NERs in soil. Our results provide unique insights into the fate of BPS in soil and suggest that while BPS is biodegradable, it includes the formation of large amounts of reversibly physico-chemically entrapped and covalently bound ester-linked NERs. The instability of these NERs should be considered in assessments on environmental persistence and risks of BPS. Our study also points out the environmental importance of NERs of agrochemicals.

Insights into the interactions of bisphenol and phthalate compounds with unamended and carnitine-amended montmorillonite clays

Montmorillonite clays could be promising sorbents to mitigate toxic compound exposures. Bisphenols A (BPA) and S (BPS) as well as phthalates, dibutyl phthalate (DBP) and di-2-ethylhexyl phthalate (DEHP), are ubiquitous environmental contaminants linked to adverse health effects. Here, we combined computational and experimental methods to investigate the ability of montmorillonite clays to sorb these compounds. Molecular dynamics simulations predicted that parent, unamended, clay has higher binding propensity for BPA and BPS than for DBP and DEHP; carnitine-amended clay improved BPA and BPS binding, through carnitine simultaneously anchoring to the clay through its quaternary ammonium cation and forming hydrogen bonds with BPA and BPS. Experimental isothermal analysis confirmed that carnitine-amended clay has enhanced BPA binding capacity, affinity and enthalpy. Our studies demonstrate how computational and experimental methods, combined, can characterize clay binding and sorption of toxic compounds, paving the way for future investigation of clays to reduce BPA and BPS exposure.

Long-term bisphenol S exposure aggravates non-alcoholic fatty liver by regulating lipid metabolism and inducing endoplasmic reticulum stress response with activation of unfolded protein response in male zebrafish

Environmental chemical exposures have been implicated as risk factors for the development of non-alcoholic fatty liver (NAFLD). Bisphenol S (BPS), widely used in multitudinous consumer products, could disrupt lipid metabolism in the liver. This study aimed at examining the hypothesis that long-term exposure to BPS promotes the development of liver fibrosis and inflammation by means of the application of a semi-static exposure experiment that exposed zebrafish to 1, 10, and 100 μg/L BPS from 3 h post fertilization to 120 day post fertilization. Results showed that the 120-d BPS exposure elevated plasma aspartate aminotransferase and alanine aminotransferase activities, increased triacylglycerol (TAG) and total cholesterol levels in male liver, and even induced hepatic apoptosis and fibrosis. Hepatic lipid accumulation observed in the 30-d BPS-exposed zebrafish was recovered after a 90-d depuration phase, thereby indicating that long-term BPS exposure promotes the progression of simple steatosis to non-alcoholic steatohepatitis. Furthermore, BPS exposure for 120-d promoted the synthesis of TAG and lipotoxic free fatty acids by elevating the transcription of srebp1, acc, fasn, and elovl6, induced endoplasmic reticulum (ER) stress with increasing expression levels of unfolded protein response (UPR) genes (perk, hsp5, atf4a, and ddit3), and then stimulated the expression of two key autophagy genes (atg3 and lc3) and inflammatory genes (il1b and tnfα). It is indicated that BPS can induce the development of steatohepatitis via the activation of the PERK-ATF4a pathway of the UPR. Data gathered suggest that environmental pollutants-induced ER stress with the activation of UPR can potentially trigger the NAFLD development in males. Overall, our study provided new sights into understanding of the adverse health effects of metabolism disrupting chemicals.

The quantification of bisphenols and their analogues in wastewaters and surface water by an improved solid-phase extraction gas chromatography/mass spectrometry method

The study focused on the application of GC in the quantitative analysis of bisphenols and their analogues (12 analytes), and the improvement of solid-phase extraction for the whole water analysis of complex water samples. The role of silylation in the qualitative and quantitative analysis of bisphenols was investigated. Partial degradation occurred for selected targets during hot injection with the presence of a silylation agent. A PSA (primary and secondary amines) sorbent placed on the top of the solid-phase extraction (SPE) column sorbent was found to be a matrix component trap, mostly for humic acids. The whole water analysis was performed by washing the filters with methanol and recycling the extract to the sample. The validation of SPE-GC/MS(SIM) gave limits of detection of 1-50 ng/L for ten target bisphenols with a method recovery of between 87 and 133%. The application of the method was tested by the analysis of wastewater sampled from three wastewater treatment plants located in Poland, and municipal surface waters. The only analytes found were BPA and BPS, within the range of 16-1465 ng/L and < MDL-1249 ng/L in wastewater, and 170-3113 ng/L and < MDL-1584 ng/L in surface water, respectively.

Bisphenol A-induced metabolic disorders: From exposure to mechanism of action

Bisphenol A (BPA) is considered as ubiquitous xenooestrogen and an endocrine disrupting chemical which has deleterious effects on endocrine functions. Human populations are continuously exposed to BPA as it is abundant in daily life. It has been found to be associated with wide range of metabolic disorders notably type 2 diabetes mellitus (DM). Numerous epidemiological studies have been conducted to find its role in development of DM. Experimental studies have found that BPA exposure is associated with pathogenesis of DM and also considered as a risk factor for gestational diabetes. Being a lipophilic compound, BPA is preferably accumulated in adipose tissues where it alters the production of adipokines that play important roles in insulin resistance. BPA induces apoptosis by caspase activation after mitochondrial damage and it impairs insulin signaling pathways by altering associated ion channel activity especially potassium channels. Perinatal exposure of BPA makes offspring more susceptible to develop DM in early years. Epigenetic modifications are the key mechanisms for BPA-induced metabolic re-programming, where BPA alters the expression of DNA methyltransferases involved in methylation of various genes. In this way, DNA methyltransferase controls the expression of numerous genes including genes important for insulin secretion and signaling. Furthermore, BPA induces histone modifications and alters miRNA expression. In this article, we have briefly described the sources of BPA exposure to human being and summarized the evidence from epidemiological studies linking DM with BPA exposure. Additionally, we have also highlighted the potential molecular pathways for BPA-induced DM.

Chronic exposure to environmentally relevant concentrations of bisphenol S differentially affects cognitive behaviors in adult female zebrafish

Evidence is emerging that environmental exposure to bisphenol S (BPS), a substitute for bisphenol A (BPA), to humans and wildlife is on the rise. However, research on the neurobehavioral effects of this endocrine disruptive chemical is still in its infancy. In this study, we aimed to investigate the effects of long-term exposure to environmentally relevant concentrations of BPS on recognition memory and its mechanism(s) of action, especially focusing on the glutamatergic/ERK/CREB pathway in the brain. Adult female zebrafish were exposed to the vehicle, 17β-estradiol (E2, 1 μg/L), or BPS (1, 10 and 30 μg/L) for 120 days. Fish were then tested in the object recognition (OR), object placement (OP), and social recognition tasks (SR). Chronic exposure to E2 and 1 μg/L of BPS improved fish performance in OP task. This was associated with an up-regulation in the mRNA expression of several subtypes of metabotropic and ionotropic glutamate receptors, an increase in the phosphorylation levels of ERK1/2 and CREB, and an elevated transcript abundance of several immediate early genes involved in synaptic plasticity and memory formation. In contrast, the exposure to 10 and 30 μg/L of BPS attenuated fish performance in all recognition memory tasks. The impairment of these memory functions was associated with a marked down-regulation in the expression and activity of genes and proteins involved in glutamatergic/ERK/CREB signaling cascade. Collectively, our study demonstrated that the long-term exposure to BPS elicits hermetic effects on the recognition memory in zebrafish. Furthermore, the effect of BPS on the recognition memory seems to be mediated by the glutamatergic/ERK/CREB signaling pathway.

Long-term exposure of zebrafish to bisphenol S impairs stress function of hypothalamic-pituitary-interrenal axis and causes anxiety-like behavioral responses to novelty

Bisphenol S (BPS), a main substitute of bisphenol A, has been reported to induce multiple endocrine disrupting effects on animals, however, whether it can interfere with the corticosteroid-endocrine system still remains unknown. Furthermore, previous studies mainly investigated the influences of environmental pollutants on corticosteroid levels and gene expressions of hypothalamic-pituitary-interrenal/adrenal (HPI/A) axis, while the downstream toxic effects caused thereafter have not yet been fully elucidated. Considering the key role of cortisol, a primary corticosteroid hormone in teleost, in mediating stress adaptation and the highly positive correlation between cortisol level and anxious phenotype in the novel environment, we hypothesized that an imbalanced cortisol homeostasis due to environmental pollutant exposure may further affect the behavioral responses to novelty stress. In the present study, zebrafish, a valuable model in studying human stress physiology and anxiety behavior, were exposed to BPS from embryos to adults (120 days) at environmentally relevant concentrations (1 and 10 μg/L) and 100 μg/L. Results found that long-term exposure to BPS increased whole-body cortisol levels and caused abnormal expressions of HPI axis genes. Moreover, the excessive cortisol levels may be due to the inhibition of cortisol catabolism and excretion, as evidenced by the down-regulated expressions of hydroxysteroid 11-beta dehydrogenase 2 and hydroxysteroid 20-beta dehydrogenase 2 genes. More importantly, as we speculated, excessive cortisol levels may be responsible for the occurrence of anxiety-like behavioral responses indicated by longer latency, fewer time spent in the upper half, and more erratic movements in a 6-min novel tank test. Overall, our study provides basic data for the comprehensive understanding of BPS toxicity, and emphasizes environmental health risks of BPS in inducing anxiety syndrome at environmentally realistic concentrations.

Toxicokinetics of bisphenol-S and its glucuronide in plasma and urine following oral and dermal exposure in volunteers for the interpretation of biomonitoring data

The measurement of bisphenol-S (BPS) and its glucurono-conjugate (BPSG) in urine may be used for the biomonitoring of exposure in populations. However, this requires a thorough knowledge of their toxicokinetics. The time courses of BPS and BPSG were assessed in accessible biological matrices of orally and dermally exposed volunteers. Under the approval of the Research Ethics Committee of the University of Montreal, six volunteers were orally exposed to a BPS-d8 deuterated dose of 0.1 mg/kg body weight (bw). One month later, 1 mg/kg bw of BPS-d8 were applied on 40 cm² of the forearm and then washed 6 h after application. Blood samples were taken prior to dosing and at fixed time periods over 48 h after treatment; complete urine voids were collected pre-exposure and at pre-established intervals over 72 h postdosing. Following oral exposure, the plasma concentration-time courses of BPS-d8 and BPSG-d8 over 48 h evolved in parallel, and showed a rapid appearance and elimination. Average peak values (±SD) were reached at 0.7 ± 0.1 and 1.1 ± 0.4 h postdosing and mean (±SD) apparent elimination half-lives (t_½) of 7.9 ± 1.1 and 9.3 ± 7.0 h were calculated from the terminal phase of BPS-d8 and BPSG-d8 in plasma, respectively. The fraction of BPS-d8 reaching the systemic circulation unchanged (i.e. bioavailability) was further estimated at 62 ± 5% on average (±SD) and the systemic plasma clearance at 0.57 ± 0.07 L/kg bw/h. Plasma concentration-time courses and urinary excretion rate profiles roughly evolved in parallel for both substances, as expected. The average percent (±SD) of the administered dose recovered in urine as BPS-d8 and BPSG-d8 over the 0-72 h period postdosing was 1.72 ± 1.3 and 54 ± 10%. Following dermal application, plasma levels were under the lower limit of quantification (LLOQ) at most time points. However, peak values were reached between 5 and 8 h depending on individuals, suggesting a slower absorption rate compared to oral exposure. Similarly, limited amounts of BPS-d8 and its conjugate were recovered in urine and peak excretion rates were reached between 5 and 11 h postdosing. The average percent (±SD) of the administered dose recovered in urine as BPS-d8 and BPSG-d8 was about 0.004 ± 0.003 and 0.09 ± 0.07%, respectively. This study provided greater precision on the kinetics of this contaminant in humans and, in particular, evidenced major differences between BPA and BPS kinetics with much higher systemic levels of active BPS than BPA, an observation explained by a higher oral bioavailability of BPS than BPA. These data should also be useful in developing a toxicokinetic model for a better interpretation of biomonitoring data.

Bisphenols B, E, F, and S and 4-cumylphenol induce lipid accumulation in mouse adipocytes similarly to bisphenol A

Bisphenol A (BPA) has been widely reported to exert endocrine disrupting effects, including the induction of adipogenesis in cultured preadipocytes and intact animals. Because of the potential harm to human health, BPA is being substituted by structurally related bisphenols. Whether or not such BPA analogues are safe substitutes, however, remains largely unknown. Here, we investigated the potential of bisphenol B (BPB), bisphenol E (BPE), bisphenol F (BPF), bisphenol S (BPS), and 4-cumylphenol (4-CP) to affect lipid and hormone levels in 3 T3-L1 cells. We found that BPB, BPE, BPF, BPS, and 4-CP all affected lipid accumulation and leptin levels to the same extent and potencies as BPA. Based on these and other results, we conclude that these BPA analogues and 4-CP most likely will elicit similar effects on adipocytes as BPA. Using them to substitute BPA in products should be done with caution.

Bisphenol S adsorption with activated carbon prepared from corncob: optimization using response surface methodology

Activated carbon derived from raw corncob (CCAC), which prepared with steam as the activating agent, was used to adsorb bisphenol S (BPS) from aqueous solution. Characterizations of CCAC were measured by using the Brunauer-Emmett-Teller, scanning electron microscopy, and Fourier transform infrared spectroscopy. Adsorption conditions including initial BPS concentration, contact time, adsorbent dosage and pH were optimized by response surface methodology (RSM). The results show that adsorption equilibrium was well described by the Langmuir and Koble–Corrigan models. The maximum monolayer adsorption capacity of BPS was found to be 617.29 mg g−1 at 298 K. Based on the thermodynamic parameters analysis, the BPS adsorption process was turned out to be spontaneous and exothermic. The adsorption process of BPS was well described by the pseudo-second-order kinetic model. It also found that H-bonding, π–π interaction, and electrostatic interaction were the main mechanisms in the process of BPS adsorption onto the CCAC.