长江口表层沉积物中多氯联苯残留和风险评价

Residual Characteristics and Ecological Risk Assessment of Polychlorinated Biphenyls in Surface Sediments from Yangtze Estuary and Nearshore of East China Sea

摘要:

采用GCECD(gas chromatographyelectron capture detector)对14种多氯联苯(polychlorinated biphenyls,PCBs)在长江口及东海近岸沉积物中的残留水平进行了测定,对其分布、组分特征、来源及生态风险水平进行了探讨.结果表明：多氯联苯在表层沉积物中的质量分数为18.66～87.31 ng·g-1(平均值为41.65 ng·g-1),以三氯和四氯联苯为主,占多氯联苯总量的32.49%～96.43%;相关性分析揭示总有机碳是影响沉积物中多氯联苯分布的重要原因;主成分因子分析法对多氯联苯来源的研究显示多氯联苯污染主要来源于电力电容器的浸渍剂等工业品的生产;采用毒性当量因子(toxic equivalency factors,TEFs)法和沉积物环境质量标准ISQG (interim sediment quality guideline) 对多氯联苯污染状况进行了初步评价,与国内外水体沉积物相比,长江口及东海近岸多氯联苯污染水平或毒性当量处于中等水平,具有一定的潜在生态风险,应加强污染监管.

Abstract:

Concentration of 14 polychlorinated biphenyls (PCBs) residues in sediments from Yangtze Estuary and nearshore of the East China Sea were determined by gas chromatographyelectron capture detector (GCECD).The concentration of PCBs in sediments were in the range of 18.66-87.31 ng·g-1.This paper will discuss PCB polluted sediments in the research area in terms of the distribution of PCBs,the pollution level,and the PCBs sources.According to component analysis,the types of PCBs found in the surface sediments were mainly 3 & 4 CB PCBs,accounting for 32.49%-96.43% of the total PCBs found.The principal factor analysis revealed that the PCBs in the sediments were mainly from industrial pollution.Correlation analysis revealed total organic carbon (TOC) content strongly influenced the distribution of OCPs in sediments.Compared with other regions around the world,the pollution level of PCBs was,in general,at a moderate level.The ecological risk assessment by the methods of calculating toxic equivalent quantity (TEQPCB) and comparing with interim sediment quality guideline (ISQG) and probable effect level (PEL ) values of risk evaluation,indicates the PCB contaminated sediments from Yangtze River estuary and its nearshore of the East China Sea will have a medium ecological risk.