【摘要】 电子废物已被证实是众多污染物的释放源,其引起的环境问题正日益受到人们的关注。利用同位素稀释GC/MS法测定了电子废物污染区的田螺、泥鳅和鲫鱼三种水生生物体内的PCBs含量和异构体组成特征。研究结果表明,田螺、泥鳅和鲫鱼体内PCBs平均浓度分别高达1303.53、3845.00和5645.34 ng/g脂重;毒性当量(TEQs)分别为1.35、8.44和29.18 pg WHO-TEQ/g湿重。其中,泥鳅和鲫鱼体内PCBs的TEQs都高于2006年欧盟规定的鱼类可食用部分最大TEQs允许值。此外,PCB 118是PCBs的主要异构体,分别占样品中PCBs总浓度和TEQs的57.73%—61.22%和44.27%—50.61%。而且,PCB 118与PCBs的总浓度和TEQs都具有良好的线性关系,相关系数(R2)分别为0.9988(P<0.01)和0.9873(P<0.01)。这些研究结果表明,该地区的水生生物已经受到PCBs的严重污染,其体内的PCBs可能主要来自于电子废物拆解中释放的商业产品Aroclor 1254。更多还原

【Abstract】 Electronic and electrical waste(E-waste) is a waste type consisting of any broken or unwanted electrical or electronic appliance.Obsolete E-waste has become a serious problem.Many previous studies showed that persistent organic pollutants(POPs) and heavy metals caused serious contamination in air,soil,sediment and freshwater.It is drawing more and more attentions because of its adverse impacts on environment and human health.According to the State Environmental Protection Administration of China,70% of worldwide e-waste has been sent to China.Taizhou region in Zhejiang Province is one of the most intensive E-waste processing sites in China.Polychlorinated biphenyls(PCBs) were widely used worldwide as coolants and insulators in electrical capacitors and transformers,and as plasticizers in paint and rubber sealant.Large quantities of PCBs have since entered the environment through leakage,disposal,and evaporation.PCBs stability is also responsible for their continued presence in the environment even decades.Environmental levels of PCBs are traditionally measured as total PCB based on Aroclor equivalent analysis,as opposed to congener-specific concentrations,due to analytical limitations and/or cost differentials.To evaluate the true risk of PCBs to human and ecosystem health,more complex and,in turn,costly Dioxin-Like PCB-specific analytical methods(e.g.,U.S.EPA method 1668a) are available.Dioxin-like PCBs(dl-PCBs) are a group of 12 PCBs that share a common toxic mechanism with the most toxic dioxin compound(i.e.,2,3,7,8-tetrachlorodibenzop-dioxin or 2,3,7,8-TCDD) and generally are among the most toxic PCB congeners as they incur toxic effects at relatively lower concentrations than those of non-dl-PCBs.In the present study,samples of winkle,loach and crucian carp were collected from the e-waste area(Taizhou,Zhejing) in 2006.Dl-PCBs were determined in the samples using isotope dilution Gas Chromatography/Mass Spectrometry(GC/MS) method.Our results showed that the average concentrations of PCBs were 1303.53,3845.00 and 5645.34 ng/g lipid weight in winkle,loach and crucian carp,respectively.Toxic equivalencies(TEQs) were determined to be 1.35,8.44 and 29.18 pg WHO-TEQ/g wet weight in winkle,loach and crucian carp,respectively.TEQs in winkle and crucian carp exceed the European maximum permissible level(2006) of TEQs in fish for human food.In addition,PCB 118 was major congener and constituted 57.73%— 61.22% and 44.27%— 50.61% of total PCBs and TEQs,respectively.Furthermore,PCB 118 was found to have linear correlations to the total PCBs and TEQs.The correlative coefficients(R2) were 0.9988(P<0.0001) and 0.9873(P<0.0001).These results indicated that aquatic organisms from the e-waste area have been seriously contaminated by PCBs which might come from Aroclor 1254 released from E-waste dismantling.更多还原