滴水湖水系表层沉积物中多氯联苯残留与风险评价

于2012年,每2个月采集一次上海人工滩涂湖泊——滴水湖水系表层沉积物,对其多氯联苯(PCBs)的残留水平进行了检测和分析.结果表明,研究期间闸外引水河和闸内引水河沉积物中7种PCBs的总量各月间变化较大,且总体呈上升趋势,而滴水湖沉积物中其总量四季变化幅度不大;空间分布上,闸外引水河(844.74±687.62)ng/g]>闸内引水河(516.83±645.45)ng/g]>>滴水湖(81.63±72.18)ng/g].研究区PCBs组成以六氯联苯和七氯联苯为主,其次为五氯联苯和三氯联苯.采用主成分分析法对PCBs进行源解析,结果显示:PCBs污染源中进口电容器中PCBs的迁移占43%,油漆添加剂污染占33%;国产电容器和变压器污染占11%.生态风险评估表明,闸外引水河和闸内引水河沉积物PCBs对生物体的暴露有严重威胁;滴水湖沉积物PCBs对生物体的暴露有一定的潜在威胁.与国内外研究相比,闸外引水河和闸内引水河属于严重污染水平,滴水湖属于中等污染水平,相关部门应加强污染监管.

Residual characteristics and ecological risk assessment of polychlorinated biphenyls (PCBs) in the surface sediments of Dishui Lake watershed

Dishui Lake is the largest artificial lake in China. Polychlorinated biphenyls (PCBs) were measured bimonthly in sediments from Dishui Lake watershed in 2012. Total concentrations of 7PCBs increased gradually in the flowing river, while fluctuated slightly inside the lake. The spatial distribution showed that PCBs outside the diversion sluice (844.74±687.62)ng/g] was higher than that inside the diversion sluice (516.83±645.45)ng/g], and both were much higher than that in Dishui Lake (81.63±72.18)ng/g]. Judged by principal component analysis method, the possible sources included import capacitor migration (43%), paint additive pollution (33%) and domestic capacitor and transformer pollution (11%). The ecological risk assessment indicated that biological toxicity effect of PCBs was serious in the flowing river, whereas Dishui Lake had potential hazards. Compared with other studies, PCBs contaminated sediments in the flowing rivers were in a serious pollution level, while Dishui Lake was considered in a medium pollution level.