青岛近海沉积物PCBs的水平与垂直分布及贝类污染

利用13C同位素内标法及气相色谱-质谱方法对青岛胶州湾内外8个表层沉积物,1个沉积物柱状岩心和2个贝类样品中包括14种共平面PCBs在内的50种PCBs同系物含量进行了测定,在所有样品中均检测出了PCBs化合物.讨论了PCBs的分布特征.表层样品以胶州湾东岸的含量最高,从北岸、西岸、胶州湾口及胶州湾外PCBs含量逐渐降低.表层沉积物中总PCBs含量在0.65～32.9ng/g dw. PCBs总含量落在国内外海洋近岸表层沉积物含量范围的中值区.表明污染来源有城市污水排放及大气来源2种,而不属于工业污染类型.多氯联苯主要以低氯取代PCBs为主,大部分高氯取代PCBs的含量低于检出限.柱状样中共平面PCBs的含量及毒性当量浓度总的垂直变化趋势是从1951年到现在逐渐减少.贝类样品的总PCBs含量为4.9～8.4ng/g dw,属低污染水平.

Horizontal and vertical distributions of PCBs in sediments and mussel pollution in Qingdao coastal sea

Using 13C isotope inside mark and gaseous phase chromatograph-maso spectrum techniques the contents of 50 PCBs homologues (including 14 coplanar polychlorinated biphenyls) in 8 surface sediments 1 sediment columnar core and 2 mussel samples collected both inside and outside Jiaozhou Bay of Qingdao were determined; and PCBs compound was detected in all samples. The PCBs distribution character was discussed. The content of PCBs in the surface samples decreased in an order of: the eastern coast > the northern coast > the western coast >Jiaozhou Bay inlet >outside Jiaozhou Bay. The surface PCBs content ranged 0.65~32.9ng/g dw. Compared with the PCBs content in sediments of other coastal areas in China and other countries, the level of PCBs pollution in the Jiaozhou Bay was about the average of non-metropolitan cities. If showed that there were two kinds of pollution source: the atmosphere and the discharge of urban sewage; and the pollution was not of industrial type. The content of most of the high chlorine substituted PCBs was lower than the detected limit. The content and toxicity equivalent concentration total vertical change trend decreased gradually since 1951. The total PCBs content in mussel samples were 4.9~8.4ng/g dw, being of low pollution level.