应用淡水生物毒性数据推导海水水质基准的可行性及适用性初探

在海洋环境风险评价及环境标准与基准的制定中,由于海水生物毒性数据的欠缺,通常引入淡水数据加以补充,以此推导海水的预测无效应浓度(PNEC),但该方法所推导PNEC的"失真"程度目前尚未完全清晰。本研究选取了Pb、Cd、马拉硫磷和狄氏剂四种典型化合物,应用SSD模型方法比较分析了分别基于淡水生物和海水生物以及二者一并使用推导的PNEC值之间的差异性和相关性。结果发现:淡水生物与海水生物对各化合物响应的敏感性具有一定的差异。对于重金属,淡水物种可能对其胁迫更具敏感性,将淡水数据与海水数据一并使用所获得PNEC可有效的保护海洋生物;对于有机磷和有机氯农药,海水生物通常更具敏感性,淡水数据的介入和应用可能会对部分海洋生物造成部分"欠保护"现象,但总体上,淡水HC5与海水HC5二者相差不大,可通过适当的安全因子加以校正。

Preliminary analysis on feasibility and applicability of using freshwater data to extrapolate the saltwater marine quality criteria

In marine environmental risk assessment and environmental quality standards setting,there is generally a lack of saltwater toxicity data for extrapolation the PNEC(predicted no effect concentration),leaving an unknown margin of uncertainty in saltwater assessments that utilize surrogate freshwater data.Here,we use species sensitivity distributions(SSDs) to determine if freshwater datasets are adequately protective of saltwater species assemblages for four chemical substances.For the metal compounds among these data,freshwater data were generally protective because freshwater organisms tended to more sensitive.In contrast,for organophosphate and organochlorine pesticides compounds,saltwater species tended to be more sensitive,and these data suggested that freshwater data were not necessarily protective of saltwater organisms.On the basis of the data reported in this article,it seems that a modest safety factor should be applied if freshwater data are used to protect saltwater organisms from pesticides exposure.