长江口滨岸水体悬浮颗粒物中PCBs分布特征

对长江口滨岸带14个采样点水体悬浮物中的多氯联苯(PCBs)进行GC-ECD测试,结果表明PCBs含量水平为2.5～51.5ng/g,平均值为13.2ng/g,普遍高于相应表层沉积物中的含量,但没有表现出明显的与排污有关的地域性分布规律;PCBs的含量与悬浮物的粒径和有机质含量不显著相关,而可能与有机质来源和矿物组成有关;在大多数采样站位,低氯代联苯(2～5CB)占PCBs总量的70%以上,其中2CB在悬浮物中占有绝对优势地位.这一组成特征可能与我国主要生产和使用低氯代联苯有关,但与过去表层沉积物中以3CB为主的特征不同,表明可能有新的PCBs的输入.与国内外相关研究结果对比,本区PCBs的污染属中等水平.

Distribution of Polychlorinated Biphenyls(PCBs) in Suspended Particulate Matters from the Yangtze Estuarine and Coastal Areas

Polychlorinated biphenyls (PCBs) in suspended particulate matters (SPMs) from the Yangtze estuary and coastal areas were determined with GC-ECD. The results show that concentrations of PCBs range from 2.5 - 51.5 ng/g, with an average of 13.2 ng/g. PCBs concentrations are higher in SPMs than in surface sediments at most of sampling stations. It was also found that the distribution of PCBs had no significant relationship with grain size and organic matter. In addition, the congeners of PCBs were characterized by less chlorinated compounds, with 2 - 5CB accounting for 74.9% - 100% except at Donghai site, and 2CB was dominant among the congeners of PCBs in all samples, which maybe be related to the history of production and use for PCBs in China. But it was different from the surface sediments that dominated by 3CB, which showed that there was new inputs recently. Compared with the concentration levels of PCBs at other estuarine and coastal areas, it was shown that there existed a moderate level of contamination in the study area.