中国七大水系淡水沉积物中林丹(γ-HCH)的生态风险评估

Ecological Risk Assessment of γ-HCH for Freshwater Sediment of Seven Major River Systems in China

林丹(γ-HCH)作为曾广泛应用的有机氯农药,自2000年在中国停止生产以来,全国范围内环境介质中仍广泛检出,对生物体及自然环境存在潜在危害。在收集γ-HCH的沉积物毒性数据基础上,通过物种敏感度分布(Species Sensitivity Distributions,SSD)曲线拟合的方法获得其沉积物质量基准。选取7种常用模型进行拟合,通过比较,最终采用S-Logistic模型拟合γ-HCH急性毒性曲线,得到急性基准值CMCsed=0.00530μg·g^(-1);采用S-Gompertz模型拟合γ-HCH慢性毒性曲线,得到慢性基准值CCCsed=0.00106μg·g^(-1)。我国七大水系68.2%的水体沉积物中γ-HCH的残留浓度均低于其CCCsed,说明其风险较低。但是,在海河和辽河流域某些点位的残留超标,需要引起足够的重视。所获得的沉积物基准值对评估沉积物中γ-HCH的生态风险和环境修复具有重要指导意义。

As one of the widely used organochlorine pesticides, lindane（γ-HCH） has been banned since 2000, but still can be detected in the environment throughout China and may pose potential adverse effects to organisms and the environment. In this study, toxicity data of γ-HCH in sediment were collected and grouped. Then, its sediment quality criterion were derived by fitting the data using Species Sensitivity Distribution（SSD） method. Among the seven commonly used SSD models, S-Logistic and S-Gompertz models fitted the acute and chronic toxicity curves the best, respectively. Developed acute sediment quality criteria was CMCsed= 0.00530 μg·g^-1, and chronic sediment quality criteria was CCCsed= 0.00106 μg·g^-1. These sediment quality criteria provided scientific guidance for the assessment on ecological risks of γ-HCH and environment remediation.