[Research progress on the developmental toxicity and mechanism of brominated flame retardants during pregnancy exposure on offspring].

Brominated flame retardants (BFRs) are a kind of brominated compounds widely used in electronic and electrical appliances, textiles, construction materials and other industrial products to improve the flame retardant property. Because of its strong chemical stability, environmental persistence, long-distance transmission, biological accumulation, the exposure of humans and organisms in the ecosystem is increasing, and its potential biological effects are of great concern. Now BFRs can be detected in breast milk, serum, placenta and cord blood. Studies have shown that exposure to BFRs during pregnancy can lead to adverse birth outcomes such as low birth weight, malformation, gestational age changes and impairment of neurobehavioral development. This article summarizes the pollution and population exposure of three traditional BFRs, polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCD), and tetrabromobisphenol A (TBBPA), as well as the impact and mechanism of prenatal exposure on offspring birth outcomes and growth and development. It explores the harm of prenatal exposure to BFRs to offspring and proposes preventive measures for occupational populations for reference.

Assessment of the disruption effects of tetrabromobisphenol A and its analogues on lipid metabolism using multiple in vitro models.

Tetrabromobisphenol A (TBBPA), a widely-used brominated flame retardant, has been revealed to exert endocrine disrupting effects and induce adipogenesis. Given the high structural similarities of TBBPA analogues and their increasing exposure risks, their effects on lipid metabolism are necessary to be explored. Herein, 9 representative TBBPA analogues were screened for their interference on 3T3-L1 preadipocyte adipogenesis, differentiation of C3H10T1/2 mesenchymal stem cells (MSCs) to brown adipocytes, and lipid accumulation of HepG2 cells. TBBPA bis(2-hydroxyethyl ether) (TBBPA-BHEE), TBBPA mono(2-hydroxyethyl ether) (TBBPA-MHEE), TBBPA bis(glycidyl ether) (TBBPA-BGE), and TBBPA mono(glycidyl ether) (TBBPA-MGE) were found to induce adipogenesis in 3T3-L1 preadipocytes to different extends, as evidenced by the upregulated intracellular lipid generation and expressions of adipogenesis-related biomarkers. TBBPA-BHEE exhibited a stronger obesogenic effect than did TBBPA. In contrast, the test chemicals had a weak impact on the differentiation process of C3H10T1/2 MSCs to brown adipocytes. As for hepatic lipid formation test, only TBBPA mono(allyl ether) (TBBPA-MAE) was found to significantly promote triglyceride (TG) accumulation in HepG2 cells, and the effective exposure concentration of the chemical under oleic acid (OA) co-exposure was lower than that without OA co-exposure. Collectively, TBBPA analogues may perturb lipid metabolism in multiple tissues, which varies with the test tissues. The findings highlight the potential health risks of this kind of emerging chemicals in inducing obesity, non-alcoholic fatty liver disease (NAFLD) and other lipid metabolism disorders, especially under the conditions in conjunction with high-fat diets.

Effects of polymer matrix and temperature on pyrolysis of tetrabromobisphenol A: Product profiles and transformation pathways.

Plastics are crucial constituents in electronic waste (e-waste) and part of the issue in e-waste recycling and environmental protection. However, previous studies have mostly focused on plastic recovery or thermal behavior of flame retardants, but not both simultaneously. The present study simulated the process of e-waste thermal treatment to explore tetrabromobisphenol A (TBBPA) pyrolysis at various temperatures using polystyrene (PS), polyvinyl chloride (PVC), and e-waste plastics as polymer matrices. Pyrolysis of TBBPA produced bromophenol, bromoacetophenone, bromobenzaldehyde, and bromobisphenol A. Co-pyrolysis with the polymer matrices increased emission factors by 1 - 2 orders of magnitude. The pyrolytic products of TBBPA, TBBPA+PS, and TBBPA+PVC were mainly low-brominated bisphenol A, while that of TBBPA in e-waste plastics was consistently bromophenol. Increasing temperature drove up the proportions of gaseous and particulate products, but lowered the relative abundances of inner wall adsorbed and residual products in pyrolysis of pure TBBPA. In co-pyrolysis of TBBPA with polymer matrix, the proportions of products in different phases were no longer governed solely by temperature, but also by polymer matrix. Co-pyrolysis of TBBPA with PS generated various bromophenols, while that with PVC produced chlorophenols and chlorobrominated bisphenol A. Transformation pathways, deduced by ab initio calculations, include hydrogenation-debromination, isopropylphenyl bond cleavage, oxidation, and chlorination.

Sub-inhibitory concentrations of tetrabromobisphenol A induce the biofilm formation of methicillin-resistant Staphylococcus aureus.

Biofilm formation by methicillin-resistant Staphylococcus aureus (MRSA) on indwelling medical devices complicates the treatment of infection. Tetrabromobisphenol A (TBBPA), a synthetic, lipophilic, halogenated aromatic compound widely used as an additive in plastics and electronic products, has raised environmental concerns due to its potential for bioaccumulation. This study investigated the impact of sub-inhibitory concentrations of TBBPA on MRSA biofilm formation. Crystal violet staining and confocal laser scanning microscopy analysis demonstrated that 1/8 MIC (0.5 µg/mL) of TBBPA significantly stimulated MRSA biofilm formation (P < 0.0001). MTT assays indicated that the metabolic activity within the biofilms increased by 15.60-40.85% compared to untreated controls. Dot blot immunoassay, autolysis assay, and extracellular DNA (eDNA) quantification further revealed TBBPA enhanced the production of polysaccharide intercellular adhesin (PIA) and eDNA, which are key biofilm components. Additionally, TBBPA was found to enhance the production of staphyloxanthin, facilitating MRSA survival under oxidative conditions and in human whole blood. RT-qPCR analysis showed that TBBPA significantly upregulated genes associated with biofilm formation (icaA, atlA, sarA), staphyloxanthin biosynthesis (crtM and sigB), and oxidative stress responses (sodA and katA). These findings suggest that TBBPA promotes MRSA biofilm development and enhances bacterial resistance to adverse conditions, thereby potentially exacerbating risks to human health.

Brominated flame retardants in surface sediment from Western Guangdong, South China: Occurrence, distribution and toxicity in Caenorhabditis elegans.

Sediment is the ultimate sink of environmental pollutants. A total of 128 surface sediment samples were collected from 8 rivers and 3 reservoirs in Maoming City, Guangdong Province. This study assessed the content and distribution of brominated flame retardants in sediments. The acute toxicity effects of tetrabromobisphenol A (TBBPA) and hexabromocyclododecane (HBCDs) in sediments were evaluated using Caenorhabditis elegans as model organisms. The concentration of TBBPA in sediments ranged from not detected (ND) to 12.59 µg/kg and was mainly distributed in the central area, which was affected by the emission of TBBPA from residential and factory. The concentration of HBCDs ranged from ND to 6.31 µg/kg, and the diastereoisomer distribution was consistent, showing a trend close to the South China Sea. The composition pattern of HBCDs in the surface sediments from rivers were 41.73%-62.33%, 7.89%-25.54%, and 18.76%-40.65% for α-, ß-, and γ-HBCD, respectively, and in the sediments from reservoirs were 26.15%-45.52%, 7.44%-19.23%, and 47.04%-61.89% for α-, ß-, and γ-HBCD, respectively. When the sum of concentrations of TBBPA and HBCD in sediments were above high levels, reactive oxygen species in nematodes significantly increased, resulting in an oxidative stress response. Intestinal permeability was also enhanced, causing intestinal damage. In addition, in terms of this study, TBBPA had a greater impact on biotoxicity compared to HBCDs, and more attention should be paid to the toxic effects of the river ecosystem organisms in Maoming City, Guangdong Province. This study can complement the pollution database in the study area and provide basic data for pollution control.

Evaluating effects of tetrabromobisphenol A and microplastics on anaerobic granular sludge: Physicochemical properties, microbial metabolism, and underlying mechanisms.

Tetrabromobisphenol A (TBBPA) and microplastics are emerging contaminants of widespread concern. However, little is known about the effects of combined exposure to TBBPA and microplastics on the physicochemical properties and microbial metabolism of anaerobic granular sludge. This study investigated the effects of TBBPA, polystyrene microplastics (PS MP) and polybutylene succinate microplastics (PBS MP) on the physicochemical properties, microbial communities and microbial metabolic levels of anaerobic granular sludge. The results showed that chemical oxygen demand (COD) removal of sludge was lowest in the presence of TBBPA alone and PS MP alone with 33.21% and 30.06%, respectively. The microorganisms promoted the secretion of humic substances under the influence of TBBPA, PS MP and PBS MP. The lowest proportion of genes controlling glycolytic metabolism in sludge was 1.52% when both TBBPA and PS MP were added. Microbial reactive oxygen species were increased in anaerobic granular sludge exposed to MPS. In addition, TBBPA treatment decreased electron transfer of the anaerobic granular sludge and disrupted the pathway of anaerobic microorganisms in acquiring adenosine triphosphate, and MPs attenuated the negative effects of TBBPA on the acetate methanogenesis process of the anaerobic granular sludge. This study provides a reference for evaluating the impact of multiple pollutants on anaerobic granular sludge.

Epigenetic implications of common brominated flame retardants (PBDEs and TBBPA): Understanding the health risks of BFRs exposure.

Brominated flame retardants (BFRs) are synthetic chemicals incorporated into a wide variety of products, both for industrial applications and everyday use, with the primary aim of reducing their flammability or reducing the material burning rate. These compounds find widespread use in plastics, textiles, and electrical/electronic devices. However, BFRs can be released from products and, thus are determined in many environmental matrices such as soil, water and air.This review discuss the potential health implications of selected BFRs (PBDEs and TBBPA) exposure arising from their impact on the epigenetic mechanisms. Epigenetic modifications, such as DNA methylation and histone acetylation or methylation, as well as changes in miRNA pattern, play significant roles in gene expression and cell function and can be influenced by environmental factors.The studies indicate that PBDEs exposure can lead to global DNA hypomethylation, disrupting normal gene regulation and contributing to genomic instability. In animal models, PBDEs have been associated with adverse effects on neurodevelopment, including impairments in memory and learning. TBBPA exposure has also been linked to changes in DNA methylation patterns, alterations in histone posttranslational modifications and non-coding RNA expression. These epigenetic changes may contribute to health issues related to growth, development, and endocrine functions.The growing evidence of epigenetic modifications induced by BFRs exposure highlights the importance of understanding their potential risks to human health. Further investigations are needed to fully elucidate the long-term consequences of altered epigenetic marks and their impact on human health.

Exposure to synthesized tribromobisphenol A and critical effects: Metabolic pathways, disease signature, and benchmark dose derivation.

2,2',6-Tribromobisphenol A (Tri-BBPA), the main debrominated congener of tetrabromobisphenol A (TBBPA), is ubiquitous in the environment and human body but with unknown toxicity. Tri-BBPA was synthesized and applied to investigate its sub-chronic exposure effects on 28 organ coefficients and clinical health indicators related to liver function, kidney function, and cardiovascular system function in female mice. Results showed that the liver was the targeted organ of Tri-BBPA exposure. Compared to the control group, the changes in liver coefficient, cholinesterase, total protein, albumin, γ-glutamyl transpeptidase, lactate dehydrogenase, and creatine kinase levels ranged from -61.2 % to 35.5 % in the high-exposed group. Creatine kinase was identified as a critical effect indicator of Tri-BBPA exposure. Using the Bayesian benchmark dose derivation method, a lower reference dose than TBBPA was established for Tri-BBPA (10.6 µg/kg-day). Serum metabolomics revealed that Tri-BBPA exposure may primarily damage the liver by disrupting tryptophan metabolism related to L-alanine, tryptamine, 5-hydroxyindoleacetic acid, and 5-methoxyindoleacetate in liver cells and leading to liver dysfunction. Notably, epilepsy, schizophrenia, early preeclampsia, and late-onset preeclampsia were the top six enriched diseases, suggesting that the nervous system may be particularly affected by Tri-BBPA exposure. Our findings hinted a non-negligible health risk of exposure to debrominated products of TBBPA.

Tetrabromobisphenol A reduces male rats reproductive organ coefficients and disrupting sexual hormone by causing oxidative stress.

Tetrabromobisphenol A (TBBPA) has become a topic of public attention due to its pervasive detection in the environment and organisms in recent decades. However, limited information is available regarding the toxicity of TBBPA on reproductive ability of male mammals. Herein, the reproductive toxicity of TBBPA was investigated in male rats to fill the knowledge gap. In this study, male rats were exposed to TBBPA (0, 10, 100, and 1000 mg/kg) for 6 weeks. Subsequently, body and organ indexes, histopathological evaluation of testis and epididymis, ultrastructural observation of sperm, testosterone and progesterone levels, and oxidative stress indicators were conducted to reveal corresponding mechanisms. Results obtained showed that compare to the control group, the body weight, testes weight, epididymis weight, seminal vesicle and coagulation glands weight of rats in the 1000 mg/kg group lost 8.30%, 16.84%, 20.16%, 19.72% and 26.42%, respectively. Intriguingly, exposure to TBBPA (10, 100, 100 mg/kg) resulted in substantial pathological damage in testis, epididymis and sperm. TBBPA exposure also increased malondialdehyde (MDA) and hydrogen peroxide (H2O2) contents, as well as superoxide dismutase (T-SOD) and catalase (CAT) activities in testicular tissue. What's more, the testosterone and progesterone levels in male rat serum were significantly decreased after exposure to TBBPA for 6 weeks. Meanwhile, results of molecular docking showed that TBBPA has a strong affinity with estrogen receptors (ERs). These findings demonstrated that TBBPA exposure negatively impacts the reproductive ability of male rats, thus providing new insights for risk assessment for reproductive health under TBBPA exposure.

Biomass-derived cellulose nanocrystals modified nZVI for enhanced tetrabromobisphenol A (TBBPA) removal.

Nano zero-valent iron (nZVI) is an advanced environmental functional material for the degradation of tetrabromobisphenol A (TBBPA). However, high surface energy, self-agglomeration and low electron selectivity limit degradation rate and complete debromination of bare nZVI. Herein, we presented biomass-derived cellulose nanocrystals (CNC) modified nZVI (CNC/nZVI) for enhanced TBBPA removal. The effects of raw material (straw, filter paper and cotton), process (time, type and concentration of acid hydrolysis) and synthesis methods (in-situ and ex-situ) on fabrication of CNC/nZVI were systematically evaluated based on TBBPA removal performance. The optimized CNC-S/nZVI(in) was prepared via in-situ liquid-phase reduction using straw as raw material of CNC and processing through 44 % H2SO4 for 165 min. Characterizations illustrated nZVI was anchored to the active sites at CNC interface through electrostatic interactions, hydrogen bonds and FeO coordinations. The batch experiments showed 0.5 g/L CNC-S/nZVI(in) achieved 96.5 % removal efficiency at pH = 7 for 10 mg/L initial TBBPA. The enhanced TBBPA dehalogenation by CNC-S/nZVI(in), involving in initial adsorption, reduction process and partial detachment of debrominated products, were possibly attributed to elevated pre-adsorption capacity and high-efficiency delivery of electrons synergistically. This study indicated that fine-tuned fabrication of CNC/nZVI could potentially be a promising alternative for remediation of TBBPA-contaminated aquatic environments.

Association of tetrabromobisphenol A (TBBPA) with micro/nano-plastics: A review of recent findings on ecotoxicological and health impacts.

Despite the diverse research into the environmental impact of plastics, several stones have yet to be unraveled in terms of their ecotoxicological potential. Moreover, their detrimental impacts have become terrifying in recent years as the understanding of their tendency to associate and form cohorts with other emerging contaminants grew. Despite the hypothesis that microplastics may potentially adsorb organic pollutants, sequestering and making them not bioavailable for enhanced toxicity, evidence with pollutants such as Tetrabromobisphenol A (TBBPA) defers this assertion. TBBPA, one of the most widely used brominated flame retardants, has been enlisted as an emerging contaminant of serious environmental and human health concerns. Being also an additive to plasticware, it is not far to suspect that TBBPA could be found in association with micro/nanoplastics in our environment. Several pieces of evidence from recent studies have confirmed the micro/nanoplastics-TBBPA association and have exposed their compounded detrimental impacts on the environment and human health. This study, therefore, presents a comprehensive and up-to-date review of recent findings regarding their occurrence, factors that foster their association, including their sorption kinetics and isotherms, and their impacts on aquatic/agroecosystem and human health. The way forward and prospects for future studies were presented. This research is believed to be of significant interest to the readership due to its relevance to current environmental challenges posed by plastics and TBBPA. The study not only contributes valuable insights into the specific interaction between micro/nanoplastics and TBBPA but also suggests the way forward and prospects for future studies in this field.

Complete biodegradation of tetrabromobisphenol A through sequential anaerobic reductive dehalogenation and aerobic oxidation.

Tetrabromobisphenol A (TBBPA), a common brominated flame retardant and a notorious pollutant in anaerobic environments, resists aerobic degradation but can undergo reductive dehalogenation to produce bisphenol A (BPA), an endocrine disruptor. Conversely, BPA is resistant to anaerobic biodegradation but susceptible to aerobic degradation. Microbial degradation of TBBPA via anoxic/oxic processes is scarcely documented. We established an anaerobic microcosm for TBBPA dehalogenation to BPA facilitated by humin. Dehalobacter species increased with a growth yield of 1.5 × 108 cells per µmol Br- released, suggesting their role in TBBPA dehalogenation. We innovatively achieved complete and sustainable biodegradation of TBBPA in sand/soil columns columns, synergizing TBBPA reductive dehalogenation by anaerobic functional microbiota and BPA aerobic oxidation by Sphingomonas sp. strain TTNP3. Over 42 days, 95.11 % of the injected TBBPA in three batches was debrominated to BPA. Following injection of strain TTNP3 cells, 85.57 % of BPA was aerobically degraded. Aerobic BPA degradation column experiments also indicated that aeration and cell colonization significantly increased degradation rates. This treatment strategy provides valuable technical insights for complete TBBPA biodegradation and analogous contaminants.

Mechanism of tartaric acid mediated dissipation and biotransformation of tetrabromobisphenol A and its derivatives in soil.

Biotransformation is a major dissipation process of tetrabromobisphenol A and its derivatives (TBBPAs) in soil. The biotransformation and ultimate environmental fate of TBBPAs have been widely studied, yet the effect of root exudates (especially low-molecular weight organic acids (LMWOAs)) on the fate of TBBPAs is poorly documented. Herein, the biotransformation behavior and mechanism of TBBPAs in bacteriome driven by LMWOAs were comprehensively investigated. Tartaric acid (TTA) was found to be the main component of LMWOAs in root exudates of Helianthus annus in the presence of TBBPAs, and was identified to play a key role in driving shaping bacteriome. TTA promoted shift of the dominant genus in soil bacteriome from Saccharibacteria_genera_incertae_sedis to Gemmatimonas, with a noteworthy increase of 24.90-34.65% in relative abundance of Gemmatimonas. A total of 28 conversion products were successfully identified, and ß-scission was the principal biotransformation pathway for TBBPAs. TTA facilitated the emergence of novel conversion products, including 2,4-dibromophenol, 3,5-dibromo-4-hydroxyacetophenone, para-hydroxyacetophenone, and tribromobisphenol A. These products were formed via oxidative skeletal cleavage and debromination pathways. Additionally, bisphenol A was observed during the conversion of derivatives. This study provides a comprehensive understanding about biotransformation of TBBPAs driven by TTA in soil bacteriome, offering new insights into LMWOAs-driven biotransformation mechanisms.

Tetrabromobisphenol-A/S and their derivatives in surface particulates from workshop floors of three representative e-waste recycling sites in China.

Surface particulates collected from the workshop floors of three major e-waste recycling sites (Taizhou, Qingyuan, and Guiyu) in China were analyzed for tetrabromobisphenol A/S (TBBPA/S) and their derivatives to investigate the environmental pollution caused by e-waste recycling activities. Mean concentrations of total TBBPA/S analogs in surface particulates were 31,471-116,059 ng/g dry weight (dw). TBBPA, TBBPA-BGE, and TBBPA-BDBPE were the most frequently detected in particulates with average concentration ranges of 17,929-78,406, 5601-15,842, and 5929-21,383 ng/g dw, respectively. Meanwhile, TBBPA, TBBPA-BGE, and TBBPA-BDBPE were the most abundant TBBPA/S analogs, accounting for around 96% of the total. The composition profiles of TBBPA/S analogs differed significantly among three e-waste sites. Similarly, principal component analysis uncovered different pollution patterns among different sites. The discrepancy in the profiles of TBBPA/S analogs largely relied on the e-waste types recycled in different areas. E-waste recycling led to the release of TBBPA/S analogs, and TBBPA/S analogs produced differentiation during migration from source (surface particulates) to nearby soil. More researches are necessary to find a definite relationship between pollution status and e-waste types and study differentiation behavior of TBBPA/S analogs in migration and diffusion from source to environmental medium.

Insights into the influence of polystyrene microplastics on the bio-degradation behavior of tetrabromobisphenol A in soil.

Soil contamination by emerging pollutants tetrabromobisphenol A (TBBPA) and microplastics has become a global environmental issue in recent years. However, little is known about the effect of microplastics on degradation of TBBPA in soil, especially aged microplastics. In this study, the effect of aged polystyrene (PS) microplastics on the degradation of TBBPA in soil and the mechanisms were investigated. The results suggested that the aged microplastics exhibited a stronger inhibitory effect on the degradation of TBBPA in soil than the pristine microplastics, and the degradation efficiency of TBBPA decreased by 21.57% at the aged microplastic content of 1%. This might be related to the higher TBBPA adsorption capacity of aged microplastics compared to pristine microplastics. Aged microplastics strongly altered TBBPA-contaminated soil properties, reduced oxidoreductase activity and affected microbial community composition. The decrease in soil oxidoreductase activity and relative abundance of functional microorganisms (e.g., Bacillus, Pseudarthrobacter and Sphingomonas) caused by aged microplastics interfered with metabolic pathways of TBBPA. This study indicated the importance the risk assessment and soil remediation for TBBPA-contaminated soil with aged microplastics.

Tetrabromobisphenol A exerts thyroid disrupting effects but has little overt impact on postnatal brain development and neurobehaviors in mice.

Tetrabromobisphenol A (TBBPA) is a widely used brominated flame retardant. There is evidence showing that TBBPA can exert thyroid disrupting effects in mammals, but different results were also reported, along with inconsistent reports regarding its neurotoxicity. Here, we investigated thyroid disrupting effects and neurotoxicity of TBBPA (5, 50, 500 µg/(kg·day)) to male mice following maternal and direct exposure through drinking water, with the anti-thyroid drug propylthiouracil (PTU) as the positive control. On postnatal day (PND) 15, we expectedly observed severe thyroid compensatory hyperplasia and cerebellar developmental retardation in PTU-treated pups. The highest dose of TBBPA also caused thyroid histological alteration but had no effects on cerebellar development in terms of Purkinje cell morphology and the thickness of the internal granular layer and the molecular layer of the cerebellum. During puberty and adulthood, the thyroid morphological alterations became more pronounced in the TBBPA-treated animals, accompanied by decreased serum thyroid hormone levels. Furthermore, the 50 and 500 µg/(kg·day) TBBPA groups showed a significant decrease in the serum level of serotonin, a neurotransmitter associated with anxiety behaviors. Correspondingly, the highest dose group displayed anxiety-like behaviors in the elevated plus-maze test on PND 35, but this neurobehavioral alteration disappeared on PND 56. Moreover, no changes in neurobehavioral parameters tested were found in TBBPA-treated animals at puberty and adulthood. Altogether, all observations show that TBBPA can exert thyroid disrupting effects but has little overt impact on brain development and neurobehaviors in mice, suggesting that thyroid disruption does not necessarily cause overtly adverse neurodevelopmental outcomes.

Optimizing soil tetrabromobisphenol A remediation through iron-based activation of persulfate: A comparative analysis of homogeneous and heterogeneous systems.

Tetrabromobisphenol A (TBBPA) that widely exists in soil and poses a potential threat to ecological environment urgently needs economically efficient remediation techniques. This study utilized both homogeneous Fe2⁺ solution and heterogeneous iron-based nanomaterials (chemically synthesized nano zero-valence iron (nZVI) and green-synthesized iron nanoparticles (G-Fe NPs)) to activate persulfate (PS) and assess their efficacy in degrading TBBPA in soil. The results demonstrate the superior performance of heterogeneous catalytic systems (WG-Fe NPs/PS (82.07%) and WnZVI/PS (78.32%)) over homogeneous catalytic system (WFe2+/PS (71.69%)), In addition, G-Fe NPs and nZVI effectively controlled the slow release of Fe2+. The optimization analysis using response surface methodology (RSM) reveal the remarkable significance of the experimental model based on the box-behnken design. RSM show that G-Fe NPs/PS exhibited optimal process parameters and predicted the maximum soil TBBPA degradation efficiency reaching 98.77%. The results of density functional theory calculations suggest that C-Br are the primary targets for electrophilic substitution reactions. Based on the f0 value and △G, the degradation pathway of TBBPA is inferred to involve a sequential debromination process, followed by the cleavage of intermediate carbon-carbon bonds and subsequent oxidation reactions. Hence, G-Fe NPs/PS not only facilitate waste resource utilization but also hold significant application potential.

Concentration of Tetrabromobisphenol-A in fish: systematic review and meta-analysis and probabilistic health risk assessment.

Tetrabromobisphenol A (TBBP-A) is an emerging pollutant that enters water resources and affects various marine organisms, such as fish. Consequently, numerous studies globally investigated TBBP-A concentrations in fish fillets of the current study were meta-analyze concentration of TBBP-A in fish fillets and estimate the associated health risks for consumers. The search encompassed international databases, including Science Direct, PubMed, Scopus, Embase, and Web of Science from January 1, 2005, to July 20, 2023. The ranking of countries based on the pooled (Mean) concentration of TBBP-A in fish was as follows: China (1.157 µg/kg-ww) > Czech Republic (1.027 µg/kg-ww) > France (0.500 µg/kg-ww) ∼ Switzerland (0.500 µg/kg-ww) > Netherlands (0.405 µg/kg-ww) > Germany (0.33 µg/kg-ww) > Sweden (0.165 µg/kg-ww)>UK (0.078 µg/kg-ww) > Belgium (0.065 µg/kg-ww) > South Korea (0.013 µg/kg-ww) ∼ Japan (0.013 µg/kg-ww) > Ireland (0.005 µg/kg-ww). The risk assessment showed that the carcinogenic and non-carcinogenic risks of TBBP-A in China and France are higher compared to other countries; however, within all countries, these risks were found to be within acceptable limits.

Coagulation-centered three-step approach for removing by-product organic pollutants from tetrabromobisphenol A industrial wastewater: Experimental and theoretic investigations.

The challenge of meeting discharge standards for tetrabromobisphenol A (TBBPA) production wastewater, characterized by high concentrations of organic by-products, necessitates effective treatment methods. This study identifies 2,4-dibromophenol, 2,6-dibromophenol, 2,4,6-tribromophenol, chlorobenzene, and toluene as the primary organic by-product pollutants. A coagulation-centered three-step approach was established for TBBPA industrial wastewater treatment. The initial step involves acidification treatment to exploit the reduced solubility of 2,4-dibromophenol, 2,6-dibromophenol, and 2,4,6-tribromophenol under acidic conditions, with the optimal pH determined as 2.7-3.1. An acid-activated montmorillonite coagulant (AMC), prepared through roasting and high-pressure acid leaching, exhibits a distinctive "Core-shell" structure, contributing significantly to the combined coagulation and adsorption mechanism. The acid-soluble aluminum salts in AMC form positively charged flocs, electrostatically attracting negatively charged organic compounds in the wastewater. Simultaneously, the porous insoluble silicon framework displays strong adsorption capacity for pollutants. The removal efficiencies for toluene, chlorobenzene, 2,4-dibromophenol, 2,6-dibromophenol, and 2,4,6-tribromophenol reached 88.2%, 89.1%, 88.8%, 87.1%, and 89.4%, respectively. Elemental analysis reveals that the coloration of the wastewater stems from complexation reactions between phenolic compounds and Fe3+, originating from the corrosion of iron or steel reaction vessel. Post-treatment with cation exchange resin resulted in removal efficiencies of 5.2%, 59.1%, 80.2%, 77.9%, and 88.3% for the five substances, respectively. This study outlines a crucial pathway for the effective purification of TBBPA wastewater.

Hepatic glucuronidation of tetrabromobisphenol A and tetrachlorobisphenol A: interspecies differences in humans and laboratory animals and responsible UDP-glucuronosyltransferase isoforms in humans.

Tetrabromobisphenol A (TBBPA) and tetrachlorobisphenol A (TCBPA), bisphenol A (BPA) analogs, are endocrine-disrupting chemicals predominantly metabolized into glucuronides by UDP-glucuronosyltransferase (UGT) enzymes in humans and rats. In the present study, TBBPA and TCBPA glucuronidation by the liver microsomes of humans and laboratory animals (monkeys, dogs, minipigs, rats, mice, and hamsters) and recombinant human hepatic UGTs (10 isoforms) were examined. TBBPA glucuronidation by the liver microsomes followed the Michaelis-Menten model kinetics in humans, rats, and hamsters and the biphasic model in monkeys, dogs, minipigs, and mice. The CLint values based on the Eadie-Hofstee plots were mice (147) > monkeys (122) > minipigs (108) > humans (100) and rats (98) > dogs (81) > hamsters (47). TCBPA glucuronidation kinetics by the liver microsomes followed the biphasic model in all species except for minipigs, which followed the Michaelis-Menten model. The CLint values were monkeys (172) > rats (151) > mice (134) > minipigs (104), dogs (102), and humans (100) > hamsters (88). Among recombinant human UGTs examined, UGT1A1 and UGT1A9 showed higher TBBPA and TCBPA glucuronidation abilities. The kinetics of TBBPA and TCBPA glucuronidation followed the substrate inhibition model in UGT1A1 and the Michaelis-Menten model in UGT1A9. The CLint values were UGT1A1 (100) > UGT1A9 (42) for TBBPA glucuronidation and UGT1A1 (100) > UGT1A9 (53) for TCBPA glucuronidation, and the activities at high substrate concentration ranges were higher in UGT1A9 than in UGT1A1 for both TBBPA and TCBPA. These results suggest that the glucuronidation abilities toward TBBPA and TCBPA in the liver differ extensively across species, and that UGT1A1 and UGT1A9 expressed in the liver mainly contribute to the metabolism and detoxification of TBBPA and TCBPA in humans.