Novel Finding of Widespread Occurrence and Accumulation of Bisphenol A Diglycidyl Ethers (BADGEs) and Novolac Glycidyl Ethers (NOGEs) in Marine Mammals from the United States Coastal Waters

Human dietary exposure to bisphenol-diglycidyl ethers in China: Comprehensive assessment through a total diet study

Despite the widespread use of bisphenol A diglycidyl ether (BADGE) and bisphenol F diglycidyl ether (BFDGE) in various consumer products as protective plasticizer, studies on human dietary exposure to these compounds are scare. In this study, nine bisphenol diglycidyl ethers (BDGEs) including BADGE, BFDGE, and seven of their derivatives were determined in the Chinese adult population based on composite dietary samples collected from the sixth (2016-2019) China total diet study (TDS). Contamination level of nine BDGEs was determined in 288 composite dietary samples from 24 provinces in China. BADGE·2H₂O and BADGE are the most frequently detected and BADGE·2H₂O presented the highest mean concentration (2.402 μg/kg). The most contaminated food composite is meats, with a mean ∑₉BDGEs of 8.203 μg/kg, followed by aquatic products (4.255 μg/kg), eggs (4.045 μg/kg), and dairy products (3.256 μg/kg). The estimated daily intake (EDI) of ∑₉BDGEs based on the mean and 95th percentile concentrations are 121.27 ng/kg bw/day and 249.71 ng/kg bw/day. Meats, eggs, and aquatic products are the main source of dietary exposure. Notably, beverages and water, alcohols were the main contributors of dietary exposure to BADGE and BADGE·2H₂O, followed by animal-derived foods. Dietary exposure assessment demonstrated that human dietary BDGEs do not pose risks to general population based on the mean and 95th percentile hazard index with < 1. This is the first comprehensive national dietary exposure assessment of BDGEs in Chinese general population.

A comprehensive review on the analytical method, occurrence, transformation and toxicity of a reactive pollutant: BADGE

Bisphenol A diglycidyl ether (BADGE)-based epoxy resin is one of the most widely used epoxy resins with an annual production amount of several million tons. Compared with all other legacy or emerging organic compounds, BADGE is special due to its toxicity and high reactivity in the environment. More and more studies are available on its analytical methods, occurrence, transformation and toxicity. Here, we provided a comprehensive review of the current BADGE-related studies, with focus on its production, application, available analytical methods, occurrences in the environment and human specimen, abiotic and biotic transformation, as well as the in vitro and in vivo toxicities. The available data show that BADGE and its derivatives are ubiquitous environmental chemicals and often well detected in human specimens. For their analysis, a water-free sample pretreatment should be considered to avoid hydrolysis. Additionally, their complex reactions with endogenous metabolites are areas of great interest. To date, the monitoring and further understanding of their transport and fate in the environment are still quite lacking, comparing with its analogues bisphenol A (BPA) and bisphenol S (BPS). In terms of toxicity, the summary of its current studies and Environmental Protection Agency (EPA) ToxCast toxicity database suggests BADGE might be an endocrine disruptor, though more detailed evidence is still needed to confirm this hypothesis in in vivo animal models. Future study of BADGE should focus on its metabolic transformation, reaction with protein and validation of its role as an endocrine disruptor. We believe that the elucidation of BADGEs can greatly enhance our understandings of those reactive compounds in the environment and human.

Untargeted lipidomics reveals the toxicity of bisphenol A bis(3-chloro-2- hydroxypropyl) ether and bisphenols A and F in zebrafish liver cells

Given the opposing responses reported for bisphenol A (BPA) in terms of induction of obesogenic effects and impaired lipid metabolism, the increasing use of bisphenol F (BPF), and the relatively low information available regarding the effects of bisphenol A bis(3-chloro-2- hydroxypropyl) ether (BADGE·2HCl) in aquatic organisms, this work aims to use the zebrafish liver cell line (ZFL) as an alternative model to characterize the toxicity and the lipid metabolism disruptive potential of the selected compounds in fish. All three bisphenols increased intracellular levels of dihydroceramides and ether-triacylglycerides (ether-TGs), suggestive of inhibited cell growth. However, while BPA and BADGE·2HCl caused an increase of saturated and lower unsaturated TGs, BPF caused oxidative stress and the decrease of TGs containing polyunsaturated fatty acids (PUFAs). Analysis by qPCR highlighted the up-regulation of the lipogenic genes scd and elovl6 by BPA and BPF in line with an increase of lipids containing saturated and monounsaturated FA and a decrease of lipids containing PUFAs. This study shows that BPA, BPF and BADGE·2HCl target lipid homeostasis in ZFL cells through different mechanisms, and highlights the higher lipotoxicity of BADGE·2HCl compared to BPA and BPF.

PLHC-1 topminnow liver cells: An alternative model to investigate the toxicity of plastic additives in the aquatic environment

Plasticizers are widespread environmental contaminants that have been described as obesogens in terrestrial vertebrates. However, its effects on fish lipids homeostasis are almost unknown. This work explores the use of PLHC-1 cells as an alternative model to assess the disruption of hepatic lipids by plastic additives and to gather information on the mode of action of these chemicals in fish. PLHC-1 lipid extracts were analyzed by flow injection coupled to high resolution mass spectrometry (FIA-ESI(+/-)-Orbitrap-Exactive) after 24 h exposure of the cells to the selected plasticizers: dibutyl phthalate (DBP), di-(2-ethylhexyl) phthalate (DEHP), bisphenol A (BPA), bisphenol F (BPF), and chlorinated bisphenol A diglycidyl ether (BADGE·2HCl). The analysis of the culture medium and the intracellular concentration of the chemicals revealed the highest bioconcentration of BADGE·2HCl, DBP and DEHP, which was in agreement with the strongest alteration of the cells lipidome. BADGE·2HCl induced a significant depletion of triacylglycerides (TGs), while DEHP and DBP stimulated the accumulation of TGs. Exposure to BPF induced the generation of reactive oxygen species in PLHC-1 cells and a significant depletion of phosphatidylcholine (PC)- and phosphatidylethanolamine (PE)-plasmalogens, and TGs (cell depots of polyunsaturated fatty acids). Overall, this study evidences different modes of action of plastic additives in topminnow liver cells, describes differential lipidomic signatures, and highlights the higher lipotoxicity of BADGE·2HCl and BPF compared to BPA.

Stabilities of bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, and their derivatives under controlled conditions analyzed using liquid chromatography coupled with tandem mass spectrometry

Bisphenol A diglycidyl ether (BADGE), bisphenol F diglycydyl ether (BFDGE), and their related compounds are widely used as precursors in production of epoxy resins. The high reactivity of these compounds makes the development of analytical methodologies that ensure appropriate metrological accuracy crucial. Consequently, we aimed to determine whether and to what extent the composition of the solution and storage conditions affect the stability of selected BADGE and BFDGE derivatives. The stabilities of these compounds were studied using liquid chromatography–tandem mass spectrometry with electrospray ionization (HPLC-ESI–MS/MS). The chromatographic method elaborated here has allowed for separation of the analytes in time shorter than 6 min, for both methanol and acetonitrile-based mobile phases. The obtained calibration curves for all analytes were linear in the range tested. The values of limit of detection (LODs) were in the range of 0.91–2.7 ng/mL, while values of limit of quantitation (LOQs) were in the range of 2.7–5.7 ng/mL. The chosen experimental conditions were compared in terms of the content of organic solvent in solution, storage temperature, and time. Our results show that the content of BADGE, BADGE·HCl, BFDGE, three-ring NOGE decreased with increasing water content (> 40% v/v). For BADGE and three-ring NOGE, significant changes in concentration were noted as early as 24 h after the test solutions had been prepared. In addition, a reduction in the storage temperature (4 to − 20 °C) reduced the rate of transformation of the monitored analytes. Our study will increase quality control in future research and may increase the reliability of the obtained results.

Determination of Nine Bisphenol-Diglycidyl Ethers in Human Breast Milk by Ultrahigh-Performance Liquid Chromatography Tandem Mass Spectrometry

Because of their widespread use, and the mutagenicity and teratogenicity observed in in vitro studies, bisphenol-diglycidyl ethers (BDGEs) were suspected of posing health risks to humans, especially to infants. Quantifying exposure of BDGEs from breast milk is essential in assessing the potential health risks of these ubiquitous compounds to infants. However, there is no reported analytical method for the determination of BDGEs in breast milk. In this context, we developed a rapid and sensitive method based on ultrahigh-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) to measure nine BDGEs in breast milk. The analytes were extracted with acetonitrile and fat was removed by freezing under -20 °C. The extracts were further purified by PRiME HLB solid-phase extraction (SPE) cartridge. The limits of detection (LODs) and quantification (LOQs) for the analytes were 0.033-0.500 and 0.100-1.500 μg L^-1, respectively. The recoveries of BDGEs were ranged from 71.33% to 114.33%. Good method reproducibility regarding intra- and interday precision was observed, yielding relative standard deviations (RSDs) less than 11.81% and 10.83%, respectively. The proposed method was successfully applied to 20 breast milk samples. BADGE·2H₂O, BADGE·HCl·H₂O, BADGE·H₂O, BADGE·HCl, BFDGE·2H₂O, and BFDGE·2HCl were detected. BFDGE·2HCl was the dominant BDGE with detection rate of 65.0% and the concentration ranging from 0.4 to 1.0 μg L^-1. This is the first report describing the occurrence of BDGEs in breast milk.

Assessing ecotoxicity and the endocrine potential of selected phthalates, BADGE and BFDGE derivatives in relation to environmentally detectable levels

There is no doubt that the subject area of plastic materials (e.g., production of epoxy resins or polyesters) is inherently connected to issues concerning bisphenol A (BPA) and its analogues. Unfortunately, much less attention has been given to other compounds, which are also used for the production of these materials. Bisphenol A diglycidyl ether (BADGE) is a synthetic industrial compound obtained by a condensation reaction between epichlorohydrin (ECH) and BPA. Similarly, novolac glycidyl ether (BFDGE) is produced in the reaction between novolac and epichlorohydrin. Nevertheless, there is a lack of information on the combined effects of BADGE derivatives at environmentally relevant levels. In the current study, toxicity levels in Microtox® and XenoScreen YES/YAS assays were determined for several analogues alone, then the biological effects of compound pairs mixed in 33, 66 and 100% of each compounds' EC₅₀ ratios were evaluated. The Microtox® test has been chosen as a relevant tool, and the results were referred to the Xenoscreen YES/YAS assay, which has been chosen for the fast determination of the endocrine potential of the compounds tested. The results obtained constitutes the basis for model studies, with Concentration Addition (CA) and Independent Action (IA), followed by Model Deviation Ratio (MDR) interpretation, to evaluate the possible interactions occurring between analytes when present in mixtures. The results indicate that the hydrochloric derivatives of BADGE and BFDGE are of the greatest toxicological and endocrine threat. Thus, their presence in mixtures under certain environmental conditions (including presence in the tissues of living organisms) should be strictly monitored and reported, especially in acidic environments. Strong evidence on the synergic behaviors of these analytes, which expressed high toxicity (EC₅₀ 2.69-117.49μg/mL), is demonstrated with Model Deviation Ratio (MDR).

Trophic Magnification of Parabens and Their Metabolites in a Subtropical Marine Food Web

Despite the widespread use of parabens in a range of consumer products, little is known about bioaccumulation of these chemicals in aquatic environments. In this study, six parabens and four of their common metabolites were measured in abiotic (water, sediment) and biotic (fish including sharks, invertebrates, plants) samples collected from a subtropical marine food web in coastal Florida. Methyl paraben (MeP) was found in all abiotic (100%) and a majority of biotic (87%) samples. 4-Hydroxy benzoic acid (4-HB) was the most abundant metabolite, found in 97% of biotic and all abiotic samples analyzed. The food chain accumulation of MeP and 4-HB was investigated for this food web. The trophic magnification factor (TMF) of MeP was estimated to be 1.83, which suggests considerable bioaccumulation and biomagnification of this compound in the marine food web. In contrast, a low TMF value was found for 4-HB (0.30), indicating that this compound is metabolized and excreted along the food web. This is the first study to document the widespread occurrence of parabens and their metabolites in fish, invertebrates, seagrasses, marine macroalgae, mangroves, seawater, and ocean sediments and to elucidate biomagnification potential of MeP in a marine food web.

Environmental Chemicals Modulate Polar Bear (Ursus maritimus) Peroxisome Proliferator-Activated Receptor Gamma (PPARG) and Adipogenesis in Vitro

We studied interactions between polar bear peroxisome proliferator-activated receptor gamma (pbPPARG) and selected compounds using a luciferase reporter assay and predictions through molecular docking. Furthermore, we studied adipogenesis by liver and adipose tissue extracts from a polar bear and three synthetic mixtures of contaminants in murine 3T3-L1 preadipocytes and polar bear adipose tissue-derived stem cells (pbASCs). PCB153 and p,p'-DDE antagonized pbPPARG, although their predicted receptor-ligand affinity was weak. PBDEs, tetrabromobisphenol A, and PCB170 had a weak agonistic effect on pbPPARG, while hexabromocyclododecane, bisphenol A, oxychlordane, and endosulfan were weak antagonists. pbPPARG-mediated luciferase activity was suppressed by synthetic contaminant mixtures reflecting levels measured in polar bear adipose tissue, as were transcript levels of PPARG and the PPARG target gene fatty acid binding protein 4 (FABP4) in pbASCs. Contaminant extracts from polar bear tissues enhanced triglyceride accumulation in murine 3T3-L1 cells and pbASCs, whereas triglyceride accumulation was not affected by the synthetic mixtures. Chemical characterization of extracts using nontarget methods revealed presence of exogenous compounds that have previously been reported to induce adipogenesis. These compounds included phthalates, tonalide, and nonylphenol. In conclusion, major legacy contaminants in polar bear adipose tissue exert antagonistic effects on PPARG, but adipogenesis by a mixture containing emerging compounds may be enhanced through PPARG or other pathways.

Accumulation profiles of parabens and their metabolites in fish, black bear, and birds, including bald eagles and albatrosses

Although several studies have reported the ubiquitous occurrence of parabens in human specimens and the environment, little is known about the accumulation of these estrogenic chemicals in fish and birds. In this study, accumulation profiles of six parabens and their metabolites were determined in 254 tissue (including liver, kidney, egg, and plasma) samples from 12 species of fish and seven species of birds collected from inland, coastal, and remote aquatic ecosystems. In addition, liver and kidney tissues from black bears were analyzed. Methyl paraben (MeP) was found in a majority of the tissues, with the highest concentration (796ng/g (wet weight [wet wt])) found in the liver of a bald eagle from Michigan. 4-Hydroxy benzoate (HB) was the major metabolite, found in 91% of the tissue samples analyzed at concentrations as high as 68,600ng/g, wet wt, which was found in the liver of a white-tailed sea eagle from the Baltic Sea coast. The accumulation pattern of MeP and 4-HB varied, depending on the species. The mean concentrations of MeP measured in fishes from Michigan, New York, and Florida waters were <2.01 (fillet), 152 (liver), and 32.0 (liver) ng/g, wet wt, respectively, and the corresponding 4-HB concentrations were 39.5, 10,500, and 642ng/g, wet wt. The mean hepatic and renal concentrations of 4-HB in black bears were 1,720 and 1,330ng/g, wet wt, respectively. The concentrations of MeP and 4-HB were significantly positively correlated with each other in various tissues and species, which suggested a common source of exposure to these compounds in fish and birds. Trace concentrations of MeP and 4-HB also were found in the tissues of albatrosses from Midway Atoll, Northwestern Pacific Ocean, which suggested widespread distribution of these compounds in the marine environment.