以镉为研究对象,在分析我国海水水生生物区系特征的基础上,筛选了栖息我国境内的海水水生生物物种的毒性数据,采用基于物种敏感度分布(SSD)模型不同拟合曲线(log-logistic、lognormal、Gumbel、Weibull和BurrⅢ)的方法分别推导了保护水生生物的海水水质急性基准值和慢性基准值,并分析了引入淡水数据推导海水水质基准的可行性;同时,结合我国海水中镉的分布特征,对海水中镉的生态风险了初步评价。结果表明:BurrⅢ对各组数据拟合的效果最佳;引入淡水数据可能会对海水生物造成"过保护"风险;基于BurrⅢ对海水数据所推导的急性和慢性基准推荐值分别为63.0μg/L和8.0μg/L;将我国近岸水体中镉的浓度与基准值比较显示,我国近岸水体中镉对水生生物的潜在风险较低。研究结果有望为我国水质基准研究及标准制定提供参考。
The cadmium toxicity data of indigenous marine species were collected and screened on the basis of analyzing the characteristics of marine biota in China.Marine water quality criteria(WQC)of Cd were then derived using the species sensitivity distribution(SSD)approach with different regression models.The results indicated that the BurrⅢ model was better for fitting the SSD than the other four models,log-logistic,log-normal,Gumbel and Weibull.The acute and chronic marine WQC derived with BurrⅢ model were 63.0μg/L and 8.0μg/L,respectively.The feasibility of incorporating freshwater toxicity data to derive the Cd WQC was explored.It was shown that this kind of introduction derived a rather conservative marine WQC f and thus led to an"over-protection"for marine organisms.The ecological risk of Cd was preliminarily evaluated by comparing the chronic WQC value with measured ambient waterborne Cd concentrations.It was found that there existed a low ecological risk to marine biota in China coastal waters.