中文摘要：

对一受电子垃圾污染池塘内两种鱼类(鲮鱼和乌鳢)体内各组织中多氯联苯(PCBs)及其甲磺基代谢产物(Me SO2-PCBs)进行了分析.鲮鱼和乌鳢体内各组织中总PCBs(ΣPCBs)的平均含量分别为560~10 462 ng·g-1和580~50 492ng·g-1(湿重),两种鱼体内肝脏中的PCBs含量均高于其他组织.PCBs在鱼体组织内的分布与不同组织的脂肪含量有关.鲮鱼和乌鳢体内各组织中ΣMe SO2-PCBs的平均含量分别为0.44~53 ng·g-1和1.86~132 ng·g-1,这一浓度水平比之前国外报道的最高浓度高1个数量级.除PCB149外,鲮鱼体内手性PCB单体的EF值与沉积物相比存在下降趋势;而在乌鳢体内则正相反,在鲮鱼体内已下降的EF值在乌鳢体内则出现回升,有些单体的EF值甚至高于沉积物.这一结果可能表明PCBs在两种鱼体内的手性选择性代谢特征正好相反.鱼体内高含量的ΣPCBs和ΣMe SO2-PCBs对当地居民具有较高的暴露风险,因此,限制这些鱼类在市场的流通对于降低当地居民健康风险具有重要意义.

英文摘要：

In the present study, we determined polychlorinated biphenyls and their methylsulfonyl metabolites (MeSO2-PCBs) in the tissues of two fish species-mud carp and northern snakehead-from a natural pond in an electronic waste recycling site in the Pearl River Delta,Southern China. The mean concentrations of PCBs ( ΣPCBs )varied from 560 to 10 462 ng·g - 1 wet weight, and from 580 to 50 492 ng·g - 1 wet weight in the tissues of mud carp and northern snakehead, respectively, with the highest levels found in the liver. Lipid contents played an important role in the determination of tissue distribution of PCBs. The mean concentrations ofΣMeSO2-PCBs varied between 0. 44 and 53 ng·g - 1 wet weight in tissues of mud carp, while varied between 1. 86 and 132 ng·g - 1 wet weight in northern snakehead. These levels were one order of magnitude greater than the highest levels of MeSO2-PCBs previously reported in fish. The EF values of chiral PCBs in mud carp were lower than those in the sediments, with an exception of PCB149. However, the declined EFs in mud carp were rebounded in northern snakehead, and some values were even higher than those in the sediment. This result may suggest that the mud carp and the northern snakehead preferred to biotransform different enantiomers of PCB congeners. The elevated levels of ΣPCBs and ΣMeSO2-PCBs detected in the present study indicated a high exposure risk to the local residents. Restricting the consumption of these fish in the local markets is important and essential for reducing the health risks to local residents.