摘要
1,2-二溴-4-(1,2-二溴乙基)环己烷(1,2-dibromo-4-(1,2-dibromoethyl)cyclohexane,TBECH)作为一种新型溴代阻燃剂已在多种环境介质和生物体中被检出,但其毒性效应研究相当匮乏。笔者研究了赤子爱胜蚓(Eisenia fetida)对土壤中TBECH的4种异构体(α-TBECH、β-TBECH、γ-TBECH和δ-TBECH)的选择性积累,考察了TBECH对赤子爱胜蚓的生长、蚯蚓体内自由基水平、丙二醛(MDA)、磷酸化组蛋白(γ-H2AX)含量以及抗氧化酶活性的影响。结果表明,蚯蚓对TBECH的富集存在异构体选择性,γ-TBECH的生物土壤富集因子(BSAF)大于其他异构体。低浓度暴露(50~200 mg·kg^(-1))时,蚯蚓平均体质量、死亡率与空白组均无显著性差异,高浓度暴露(≥400 mg·kg^(-1))时,随暴露浓度的增加,平均体质量下降,死亡率增加。TBECH暴露过程中,蚯蚓体内MDA和γ-H2AX含量显著增加。超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)以及谷胱甘肽S转移酶(GSTs)的活性在50 mg·kg^(-1)暴露下被显著诱导,在100~600 mg·kg^(-1)暴露下,随暴露时间和浓度的增加而降低。采用电子自旋共振结合二级自由基捕获技术测定了蚯蚓体内自由基水平,发现TBECH暴露能够引起蚯蚓体内大量羟基自由基的产生,且羟基自由基水平与MDA含量存在显著正相关关系,表明诱导蚯蚓体内产生大量羟基自由基从而导致的氧化损伤是TBECH对蚯蚓产生毒性的重要原因。以上研究结果揭示了赤子爱胜蚓对TBECH的富集能力以及TBECH对赤子爱胜蚓的毒性效应,为TBECH的生态健康风险评估提供了依据。
As a novel brominated flame retardant,1,2-dibromo-4-(1,2-dibromoethyl)cyclohexane(TBECH)has been detected in a variety of environmental media and organisms,but studies on its toxic effect is quite scarce.In this work,the selective accumulation of four TBECH diastereomers(α-,β-,γ-andδ-TBECH)in soil by earthworm(Eisenia fetida)was studied.The effect of TBECH exposure on the growth of earthworm(Eisenia fetida),the free radical levels,malondialdehyde(MDA)and phosphorylated histone(γ-H2AX)contents,and antioxidant enzyme activities in earthworms were investigated.The results showed that the enrichment of TBECH by earthworms was diastereomer-specific,with the biological soil accumulation factor(BSAF)ofγ-TBECH higher than that of other diastereomers.When exposed to low TBECH concentrations(50~200 mg·kg^(-1)),the average body weight and mortality of earthworms were not significantly different from the blank group.When exposed to high TBECH concentrations(≥400 mg·kg^(-1)),the average body weight decreased with the increases of exposure concentration,and the mortality increased.During TBECH exposure,the content of MDA andγ-H2AX in earthworms increased significantly.The activity of superoxide dismutase(SOD),peroxidase(POD),catalase(CAT)and glutathione S-transferases(GSTs)was significantly induced at 50 mg·kg^(-1) exposed concentration,while decreased with increasing exposure time and concentrations at 100~600 mg·kg^(-1).The level of free radicals in earthworms was measured by electron spin resonance combined with secondary radical capture technology.It was found that TBECH exposure could induce the production of a large number of hydroxyl radicals in earthworms,and there was a significant positive correlation between the level of hydroxyl radicals and the content of MDA,which indicated that the oxidative damage caused by inducing a large number of hydroxyl radicals in earthworms is an important reason for the toxicity of TBECH to earthworms.The above research results revealed the enrichment ability of TBECH by E
作者
张贞莹
温蓓
杨恩泰
黄红林
彭汉勇
Zhang Zhenying;Wen Bei;Yang Entai;Huang Honglin;Peng Hanyong(Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,Beijing 100085,China;University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《生态毒理学报》
CAS
CSCD
北大核心
2023年第1期380-393,共14页
Asian Journal of Ecotoxicology
基金
国家重点研发计划场地土壤专项(2018YFC1801002)
国家自然科学基金资助项目(41877479,22076213)。
