宁波滩涂贝类养殖区沉积物中有机氯农药和多氯联苯残留及生态风险评估

利用GC-ECD对宁波市主要滩涂贝类养殖区表层沉积物中的多氯联苯(PCBs)和有机氯农药六六六(HCHs)、滴滴涕(DDTs)的残留量进行测定,研究其分布状况,并进行生态风险评估.结果表明:贝类养殖区表层沉积物中的总有机氯农药含量为0.80～32.40ng·g-1,多氯联苯含量为3.20～33.33 ng·g-1.HCHs主要来自远距离大气传输及历史残留,部分区域有DDTs输入,其来源可能是三氯杀螨醇的使用.大部分站位的p,p’-DDT和DDTs存在潜在的生态风险,其中墙头和西店海域的p,p’-DDT残留超过生物效应中值,对底栖生物毒害效应较高.大多数站位PCBs的生态风险较低.

Residual level and ecological risk assessment of OCPs and PCBs in sediments of mudflat shellfish culturing areas in Ningbo, Zhejiang Province of East China

GC-ECD methods were adopted to determine the residual level of OCPs (including HCHs and DDTs) and PCBs in the surface sediments collected from mudflat shellfish culturing areas in Ningbo, with the sources of the OCPs and PCBs analyzed and the ecological risks of the residual OCPs and PCBs evaluated. The residual level of OCPs was 0.80-32.40 ng X g(-1), and that of PCBs was 3.20-33.33 ng X g(-1). The HCHs mainly came from long distance atmospheric transportation and historical residues, while the DDTs had new input at some sites, possibly coming from the application of dicofol. At most sites, there existed potential ecological risks of p, p'-DDT and DDTs, with strong indications in Qiangtou and Xidian where the residual level of p, p'-DDT was higher than the effect rang median (ERM), suggesting an ecological menace to the benthos. The residual PCBs at most sites were in low level ecological risk.