海河流域水体沉积物中多氯联苯污染特征及风险评价

Pollution characteristics and risk assessment of polychlorinated biphenyls in the sediments of Haihe River Basin

截至目前,尚没有研究从流域尺度系统分析海河流域水体沉积物中多氯联苯(PCBs)的污染特征及风险水平。以海河流域7大河系及典型湖库为研究对象,基于文献中PCBs的数据统计,从流域尺度探讨了不同水体沉积物中PCBs的组成和其空间分布特征,并利用潜在生态危害指数法和毒性当量法评价其生态风险。结果表明,海河流域水体沉积物总PCBs污染呈"北高南低"趋势。二氯联苯至十氯联苯在海河流域中都有不同程度的检出,主要以低氯原子数的二氯联苯至五氯联苯为主。海河流域沉积物中PCBs毒性主要取决于PCB-126和PCB-169。两种生态风险评价方法评价结果存在一定的不确定性,需将两种方法结合,进行综合判断。

To date,there is no report to systematically elucidate the pollution characteristics and risk assessment of polychlorinated biphenyls(PCBs)in the sediments of Haihe River Basin.Based on PCBs data in previous studies,this study analyzed the spatial distribution and compositional characteristics of PCBs in the sediment of Haihe River Basin.The ecological risks of PCBs in the sediments were evaluated with potential ecological risk index method and toxic equivalent quantity method.Results indicated that the total PCBs concentration was high in north while low in south.PCBs with 2-10 chlorine atoms were all detected in Haihe River Basin,but the major components were PCBs with 2-5chlorine atoms.The toxicity of PCBs in sediments of Haihe River Basin mainly depended on PCB-126 and PCB-169.Both ecological risk assessment methods had uncertainties.Therefore,ecological risk assessment of PCBs in sediment of Haihe River Basin should consider both methods comprehensively.