Tetrabromobisphenol A and hexabromocyclododecane in sediments from the Zhujiang(Pearl) River Estuary and South China Sea

Marine sediments collected from the Zhujiang(Pearl) River Estuary(ZRE) and South China Sea(SCS) were utilized to study the occurrence and spatial distribution of tetrabromobisphenol A(TBBPA) and hexabromocyclododecane(HBCDD).The levels of TBBPA and HBCDD in sediments ranged from not detected(nd) to 6.14 ng/g dry weight(dw) and nd to 0.42 ng/g dw.TBBPA concentrations in marine sediments were substantially higher than HBCDD.The concentrations of TBBPA and HBCDD in the ZRE sediments were significantly greater than those in the SCS.α-HBCDD(48.7%) and γ-HBCDD(46.2%) were the two main diastereoisomers of HBCDD in sediments from the ZRE,with minor contribution of β-HBCDD(5.1%).HBCDD were only found in one sample from the northern SCS.The enantiomeric fraction of α-HBCDD in sediments from the ZRE was obviously greater than 0.5,indicating an accumulation of(+)-α-HBCDD.The enantiomers of HBCDD were not measured in sediments from the SCS.This work highlighted the environmental behaviors of TBBPA and HBCDD in marine sediments.

Effects of dissolved organic matter from sewage sludge on sorption of tetrabromobisphenol A by soils

Sorption of tetrabromobisphenol A (TBBPA) by soil influences its fate and transport in the environment. The presence of dissolved organic matter (DOM) may complicate the sorption process in soil. The effects of DOM from sewage sludge on TBBPA sorption by three soils were investigated using batch equilibration experiments in the study. DOM was observed to be sorbed on the soils and the isotherms could be fitted by the Langmuir model. The effects of DOM on TBBPA sorption were dependent on the characteristics ...

Toxic Effects of Tetrabromobisphenol A on Thyroid Hormones in SD Rats and the Derived-reference Dose

The present study determined the thyroid hormone interference of tetrabromobisphenol A （TBBPA） in Sprague-Dawley （SD） rats, and the derived-reference dose （RfD） of different endpoint effects on mammals based on experimental results and data collection. Based on repeated exposure toxicity tests on mammals and extensive research, the present study used BMDS240 Software to derive a benchmark dose, and analyzed the accuracy and uncertainty, and similarity with other studies. Test results on triiodothyronine （T3）, thyroxine （T4）, and thyroid stimulating hormone （TSH） demonstrated that all the indicators presented a non-monotonous dose-effect relationship clearly, except TSH in male rats exposed to 0-1000 mg/kg BW per day. Therefore, RfDs were derived from different critical effects. In summary, RfD for mammals in the present study was found to be 0.6 mg/kg per day.

Bromination of Pd Compounds during Thermal Decomposition of Tetrabromobisphenol A

We conducted thermal tests using the reagent tetrabromobisphenol A (TBBPA) and various Pd compounds to study the chemical forms of Pd obtained during the pyrolytic and oxidative decomposition of TBBPA. Thermal testing was conducted in an electric furnace at temperatures of 280°C - 800°C in an Ar or Ar-O2 (5%) atmosphere for a heating period of 40 min. Scanning electron microscopy-energy dispersive X-ray spectroscopy results revealed that Pd bromide was formed in the mixture of TBBPA and PdO after heating to 450°C in the Ar atmosphere. In addition, thermogravimetry-differential thermal analysis showed that as the heating temperature was increased from 350°C to 730°C, weight loss occurred at a nearly constant rate, indicating that Pd bromide decomposed in this temperature range.

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(5,50,500μg/(kg·day))to male mice following maternal and direct exposure through drinking water,with the antithyroid 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 500μg/(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 TBBPAtreated 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.

Toxic Effects of Tetrabromobisphenol A on Human Hepatocellular Carcinoma Cells(HepG2)Evaluated Using RNA-Seq

Tetrabromobisphenol A(TBBPA)is used as a brominated flame retardant and can easily release into environment.It has been detected in a variety of environmental media and even in food,making it a new pollutant that is potentially harmful to environment and human health.However,the toxicity and underlying mechanism of TBBPA remain to be explored.TBBPA is actively metabolized in the liver,so it is vital to study the hepatocellular toxicity of TBBPA.In this study,we treated hepatocellular carcinoma cells(HepG2)with TBBPA and searched the differentially expressed genes(DEGs)triggered by TBBPA exposure.RNA-seq analysis showed that the expression of genes,such as CLIC1 and GATSL1,were significantly down-regulated and PTENP1 was significantly up-regulated after TBBPA exposure,and these genes were involved in cell proliferation and metabolism.The down-regulated genes were enriched to peroxisome proliferator-activated receptor(PPAR)signaling pathway and up-regulated genes were enriched to Janus Kinase-signal transduces and activators of transcription(JAK-STAT)signaling pathway,which play a role in regulating cell growth.Overall,our transcriptome analysis obtained for TBBPA-treated HepG2 cells implies that TBBPA affects the cell proliferation and growth.

Tetrabromobisphenol A‑bis(2,3-dibromopropyl ether)impairs Postnatal Testis Development in Mice:The Microtubule Cytoskeleton as a Sensitive Target

Tetrabromobisphenol A-bis(2,3-dibromopropyl ether)(TBBPA-BDBPE),a widely used flame retardant,has been frequently detected in various environmental compartments,but its health hazard remains largely unknown.Here,we investigated the adverse effects of TBBPA-BDBPE(50 and 1000μg/kg/day)on postnatal testis development in CD-1 mice and the underlying mechanism.Following the first week of maternal exposure,neonatal mice in the high-dose group exhibited reduced seminiferous tubule area,fewer Sertoli cells and germ cells,and damaged microtubules in Sertoli cells;even microtubule damage was also observed in the low-dose group.When exposure extended to adulthood,male offspring in the high-dose group presented more remarkable alterations in reproductive parameters,including reduced sperm count;in the low-dose group,microtubule damage was also observable,along with blood−testis barrier impairment.Further molecular docking analysis and tubulin polymerization assay indicated that TBBPA-BDBPE could interact with tubulin and disrupt its polymerization.Moreover,we observed attenuated microtubules in mouse Sertoli cells in vitro(TM4)following TBBPABDBPE treatment,suggesting that TBBPA-BDBPE impaired testis development possibly by interfering with tubulin dynamics.This study not only highlights the male reproductive hazard of TBBPA-BDBPE but also greatly improved the understanding of the molecular mechanism for male reproductive toxicity of chemicals.

乳酸钠共代谢对铜绿假单胞菌NY3降解四溴双酚A的促进机理

通过乳酸钠共代谢提高铜绿假单胞菌NY3对TBBPA的降解速率,并对其促进机理进行研究.结果表明,以无共代谢碳源体系为对照,乳酸钠共代谢对TBBPA降解率在48h的促进最为显著,约提高了74%.乳酸钠共代谢体系的TBBPA降解活性物分布于胞内和胞外.与无共代谢碳源相比,乳酸钠共代谢不仅能提高铜绿假单胞菌NY3的生物量,还可提高其胞外液中过氧化氢、超氧负离子自由基和羟基自由基等活性氧水平.其中,胞外液中活性氧水平提高主要与NY3菌分泌到胞外的吩嗪类和喹诺酮类小分子分泌物相关.因此,乳酸钠共代谢通过胞内和胞外两方面对铜绿假单胞菌NY3降解TBBPA进行促进.

Tetrabromobisphenol A(TBBPA): A controversial environmental pollutant

Tetrabromobisphenol A(TBBPA)is one of the most widely used brominated flame retardants and is extensively used in electronic equipment,furniture,plastics,and textiles.It is frequently detected in water,soil,air,and organisms,including humans,and has raised concerns in the scientific community regarding its potential adverse health effects.Human exposure to TBBPA is mainly via diet,respiration,and skin contact.Various in vivo and in vitro studies based on animal and cell models have demonstrated that TBBPA can induce multifaceted effects in cells and animals,and potentially exert hepatic,renal,neural,cardiac,and reproductive toxicities.Nevertheless,other reports have claimed that TBBPA might be a safe chemical.In this review,we re-evaluated most of the published TBBPA toxicological assessments with the goal of reaching a conclusion about its potential toxicity.We concluded that,although low TBBPA exposure levels and rapid metabolism in humans may signify that TBBPA is a safe chemical for the general population,particular attention should be paid to the potential effects of TBBPA on early developmental stages.

Re-evaluation of thyroid hormone signaling antagonism of tetrabromobisphenol A for validating the T3-induced Xenopus metamorphosis assay

We developed the T3-induced Xenopus metamorphosis assay, which is supposed to be able to sensitively detect thyroid hormone（TH） signaling disruption of chemicals. The present study aimed to validate the T3-induced Xenopus metamorphosis assay by re-evaluating the TH signaling antagonism of tetrabromobisphenol A（TBBPA）, a known TH signaling disruptor. According to the assay we developed, Xenopus tadpoles at stage 52 were exposed to 10–500 nmol/L TBBPA in the presence of 1 nmol/L T3. After 96 hr of exposure, TBBPA in the range of 10–500 nmol/L was found to significantly inhibit T3-induced morphological changes of Xenopus tadpoles in a concentration-dependent manner in term of body weight and four morphological endpoints including head area（HA）, mouth width（MW）, unilateral brain width/brain length（ULBW/BL）, and hind-limb length/snout-vent length（HLL/SVL）.The results show that these endpoints we developed are sensitive for characterizing the antagonistic effects of TBBPA on T3-induced metamorphosis. Following a 24-hr exposure,we found that TBBPA antagonized expression of T3-induced TH-response genes in the tail,which is consistent with previous findings in the intestine. We propose that the tail can be used as an alternative tissue to the intestine for examining molecular endpoints for evaluating TH signaling disruption. In conclusion, our results demonstrate that the T3-induced Xenopus metamorphosis assay we developed is an ideal in vivo assay for detecting TH signaling disruption.

Hexabromocyclododecane and tetrabromobisphenol A in sediments and paddy soils from Liaohe River Basin, China： Levels, distribution and mass inventory

Hexabromocyclododecane （HBCD） and tetrabromobisphenol A （TBBPA） are two kinds of brominated flame retardants and widely present in the environment and biota. The levels, spatial distributions and mass inventories of HBCD and TBBPA were investigated in sediments and paddy soils from the Liaohe River Basin in northeast China. The concentrations of ∑HBCD and TBBPA were in the range of not detected （nd） to 4.02 ng/g dry weight （dw） and 0.03 to 4.06 ng/g dw, respectively, y-HBCD was dominated in sediments, while the abundance of a-HBCD was relatively high in paddy soils. The spatial distributions of HBCD and TBBPA in surface sediments and paddy soils indicated that the local point-input was their major source. The significant correlation between total organic carbon （TOC） contents and the HBCD levels suggested that TOC content also exerted an influence on the distribution of HBCD in sediments. Meanwhile, it was found that the irrigation with fiver water was not the major transportation pathway of HBCD and TBBPA in paddy soils. Based on the study, it was estimated that there were about 1.67 tons HBCD and 2.20 tons TBBPA deposited into sediments of the Liaohe River system every year. The total mass inventories of HBCD and TBBPA in sediments were far higher than that in paddy soils.

One-pot preparation of graphene oxide magnetic nanocomposites for the removal of tetrabromobisphenol A

A simple solvothermal method was used to prepare monodisperse magnetite （Fe304） nanoparticles attached onto graphene oxide （GO） sheets as adsorbents to remove tetrabromobisphenol A （TBBPA） from an aqueous solution. These Fe304/GO （MGO） nanocomposites were characterized by transmission electron microscopy. The adsorption capacity at different initial pH, contact duration, and temperature were evaluated. The kinetics of adsorption was found to fit the pseudo-second-order model perfectly. The adsorption isotherm well fitted the Langmuir model, and the theoretical maximum of adsorption capacity calculated by the Langmuir model was 27.26 mg ·g^-1 The adsorption thermodynamics of TBBPA on the MGO nanocomposites was determined at 303K, 313K, and 323 K, respectively. The results indicated that the adsorp- tion was spontaneous and endothermic. The MGO nanocomposites were conveniently separated from the media by an extemal magnetic field within several seconds, and then regenerated in 0.2 M NaOH solution. Thus, the MGO nanocomposites are a promising candidate for TBBPA removal from wastewater.

Occurrence and distribution of tetrabromobisphenol A and its derivative in river sediments from Vaal River Catchment,South Africa

Brominated flame retardants(BFRs)compounds have been widely added in a number of products to reduce their flammability.In the present study,the concentrations and distribution of tetrabromobisphenol A(TBBPA)and its derivatives,i.e.tribromophenol dibromopropyl ether(TBPDBPE),tetrabromobisphenol A bis-dibromopropyl ether(TBBPA BDBPE),tetrabromobisphenol A bis-allyl ether(TBBPA BAE)were investigated in sediment samples collected from the Vaal River catchment,South Africa.The results showed that all these pollutants were detected in sediments with TBBPA BAE being the most abundant contaminant.The TBBPA BAE concentrations ranged from 3.5 to 44.4 ng/g(mean 16 ng/g)while the concentration ranged from not detected(nd)to 2.4 ng/g(mean 0.6 ng/g),nd-21.0 ng/g(mean 6 ng/g)and nd-2.0 ng/g(mean 0.2 ng/g)for TBPDBPE,TBBPA and TBBPA BDBPE;respectively.Higher concentrations of these pollutants were found in sampling sites receiving effluents of wastewater treatment works(WWTWs)treating some industrial wastewater suggesting effluents might play an important role in the contamination of BFRs in the environment.Negative correlation between TBBPA and TBBPA BAE was observed implying different sources or environmental fates between these pollutants.Overall,the results showed a need for further studies to be undertaken in investigating the presence,fate and sources of alternative halogenated flame retardants in the environment.

WO_(3)/Bi_(2)S_(3)异质结光催化剂的制备及其降解水体中四溴双酚A的研究

目的:研究WO_(3)/Bi_(2)S_(3)异质结光催化剂在低光照强度下(100 W)对水体中四溴双酚A(TBBPA)的降解性能。方法:通过溶剂热法制备一系列不同摩尔比的WO_(3)/Bi_(2)S_(3)异质结光催化剂;采用SEM、TEM、XRD、XPS等方法对合成的材料进行表征。探究WO_(3)/Bi_(2)S_(3)在低光照强度下对TBBPA的降解效率。通过自由基淬灭实验和电子自旋光谱解析WO_(3)/Bi_(2)S_(3)光催化体系对TBBPA降解机制。结果:在100 W光照强度下,摩尔比为1∶6的WO_(3)/Bi_(2)S_(3)光催化剂在用量为60 mg以及pH为8时具有最佳的降解效率,在150 min内对5.4 mg/L TBBPA的降解率约为76.3%。此外,TBBPA的降解主要通过空穴氧化实现。结论:WO_(3)/Bi_(2)S_(3)异质结光催化剂可在低光照强度下有效降解水体中的TBBPA。

Biodegradation of tetrabromobisphenol A in the sewage sludge process

Anaerobic sewage sludge capable of rapidly degrading tetrabromobisphenol A（TBBPA） was successfully acclimated in an anaerobic reactor over 280 days. During the period from 0 to 280 days, the TBBPA degradation rate（DR）, utilization of glucose, and VSS were monitored continuously. After 280 days of acclimation, the TBBPA DR of active sludge reached 96.0% after 20 days of treatment in batch experiments. Based on scanning electron microscopy（SEM） observations and denaturing gradient gel electrophoresis（DGGE） determinations,the diversity of the microorganisms after 0 and 280 days in the acclimated anaerobic sewage sludge was compared. Furthermore, eleven metabolites, including 2-bromophenol,3-bromophenol, 2,4-dibromophenol, 2,6-dibromophenol, tribromophenol and bisphenol A,were identified by gas chromatography–mass spectrometry（GC–MS）. Moreover, the six primary intermediary metabolites were also well-degraded by the acclimated anaerobic sewage sludge to varying degrees. Among the six target metabolites, tribromophenol was the most preferred substrate for biodegradation via debromination. These metabolites degraded more rapidly than monobromide and bisphenol A. The biodegradation data of the intermediary metabolites exhibited a good fit to a pseudo-first-order model.Finally, based on the metabolites, metabolic pathways were proposed. In conclusion, the acclimated microbial consortia degraded TBBPA and its metabolites well under anaerobic conditions.

Selective separation of polychlorinated naphthalene (PCNs), hexabromocyclododecanes (HBCDs) and tetrabromobisphenol A (TBBPA) in soil matrices

A method for the selective separation of polychlorinated naphthalene (PCNs), hexabromocyclododecanes (HBCDs) and tetrabro-mobisphenol A (TBBPA) in complex matrices was developed. In the present study, the type of sorbents and the volume and composition of eluting solvents were investigated in detail. Under the optimal conditions, the recoveries of PCNs, HBCDs and TBBPA in different fractions were determined with liquid/gas chromatography tandem mass spectrometry (LC or GC-MS/MS), which was nearly close to 100%. To investigate the feasibility of the developed method, it was applied to isolate target compounds from spiked soil extracts. PCNs, HBCDs and TBBPA could be subsequently eluted with hexane, hexane/dichloromethane (1:1), and hexane/dichloromethane (1:3), and the recoveries of the analysts from three fractions were satisfactory (70.9%-107%) with the exception of -HBCD at low levels. The results indicated that the method exhibited good performance for the selective separation of PCNs, HBCDs and TBBPA and showed great potential in sample pretreatment in terms of alleviating influence from different class of impurities to some extent.

环境污染物四溴双酚A的检测进展

四溴双酚A(Tetrabromobisphenol A,TBBPA)是全球产量最高的溴化阻燃剂之一,广泛分布在空气、土壤和水中。人体接触过量TBBPA会引起内分泌系统和生殖系统紊乱,因此,高效灵敏地检测环境中TBBPA十分重要。该文综述了2012—2021年环境样品中TBBPA的检测方法,重点关注新型材料如纳米复合材料、金属有机框架材料和分子印迹聚合物等在TBBPA检测中的应用。探讨了色谱法、光谱法及电化学方法检测环境样品中TBBPA的优势、研究进展及未来发展趋势。

四溴双酚A/S及其8种衍生物在清远土壤样品中的污染特征及生态风险评估

四溴双酚A(tetrabromobisphenol-A, TBBPA)、四溴双酚S(tetrabromobisphenol-S, TBBPS)和它们的衍生物作为阻燃剂被广泛应用于日常用品,以致在多种环境介质中都能检测出它们的存在。本研究分析了清远市龙塘镇的44个土壤样品中的TBBPA、TBBPS及其8种衍生物的含量,并评估了这10种目标物的环境风险。在所有检测的目标化合物中, TBBPA、四溴双酚A双缩水甘油醚(TBBPA-BGE)和四溴双酚A双(2,3-二溴丙基醚)(TBBPA-BDBPE)是样品中的主要污染物,对目标物总浓度的贡献率分别为30%、26%和40%。TBBPA、TBBPA-BGE和TBBPA-BDBPE的浓度平均值分别为1114、1890和853ng/g(干重),浓度范围分别为ND~13098、ND~15980和ND~6088 ng/g。TBBPA、TBBPA-BGE和TBBPA-BDBPE的风险商值大于1,表明这3类化合物对清远土壤存在一定生态环境风险,应当引起重视。本研究为进一步了解常用溴系阻燃剂TBBPA、TBBPS及其衍生物的环境归趋和风险暴露提供了数据支撑。

Pd/TiO_(2)催化水体中四溴双酚A的电催化还原脱溴

以TiO_(2)、Al_(2)O_(3)、CeO_(2)和SiO_(2)为载体,采用浸渍法制备Pd基催化剂,并通过透射电镜(TEM)、X射线衍射(XRD)、X射线光电子能谱(XPS)和电感耦合等离子体发射光谱(ICP-OES)等手段对催化剂的结构进行了详细表征.以Pd/TiO_(2)为催化剂,研究四溴双酚A(TBBPA)在阴极池的电催化还原.结果表明,悬浮体系中Pd基催化剂的催化活性远高于固定体系;与其他载体相比,Pd/TiO_(2)的电催化还原活性最高;反应过程符合Langmuir-Hinshelwood模型,受控于TBBPA在催化剂表面的吸附过程;随着恒定电流和Pd负载量的增大,TBBPA电催化还原反应的初活性呈现火山型变化规律;经过5次循环使用,Pd/TiO_(2)催化剂仍能够完全去除TBBPA,具有良好的稳定性.

Fe^(2+)耦合热活化过硫酸盐降解土壤中四溴双酚A

有效降解和去除土壤中四溴双酚A(TBBPA)是土壤环境化学研究热点.本文研究了Fe^(2+)耦合热活化过硫酸盐体系(Fe^(2+)/热/PS)对土壤中TBBPA的降解,并考察温度、Fe^(2+)初始浓度、PS浓度、初始pH值、无机阴离子(Cl^(−)、HCO_(3)^(-))浓度以及金属离子(Cu^(2+)、Zn^(2+)、Ni^(2+))浓度的影响.结果表明,Fe^(2+)/热/PS降解TBBPA的效果远高于同等条件下单一热活化和Fe^(2+)活化的情况;提高温度和PS浓度能够促进土壤TBBPA的降解;而过量的亚铁离子会导致TBBPA去除率下降,Fe^(2+)与PS的最佳摩尔比为0.5:1;Fe^(2+)耦合热活化PS体系具有较宽的pH应用范围,在酸性条件下更有利于降解;温度55℃、Fe^(2+)浓度25 mmol·L^(−1)、PS浓度50 mmol·L^(−1)、pH=3下,土壤TBBPA初始浓度为20 mg·kg^(−1),培养12 h,土壤TBBPA的降解效率达到了100%;低浓度Cl−对Fe^(2+)/热/PS体系的影响不显著,高浓度的Cl−会促进TBBPA的降解,而HCO_(3)^(-)在研究浓度范围内均呈现抑制作用;Cu^(2+)和Ni^(2+)对Fe^(2+)/热/PS体系均表现出较好的促进作用,而随着Zn^(2+)浓度的增加,TBBPA的降解速率呈现出先减小后增大的变化.