Nagai Takashi, Taya Kiyoshi
National Institute for Agro-Environmental Sciences, Tsukuba, Ibaraki, Japan.
Environ Toxicol Chem. 2015 Mar;34(3):677-84. doi: 10.1002/etc.2828. Epub 2015 Feb 2.
Although species sensitivity distribution (SSD) is a key concept for quantitative ecological risk assessment, its application is limited owing to a lack of sufficient data for the analysis, especially on the toxicity of herbicides for primary producers. The authors developed a method of herbicide SSD estimation using single-species toxicity data and information on the herbicide mode of action. The authors' method was based on 2 assumptions: the slopes of the SSD of the same MOA herbicides are the same and the relative sensitivities of standard algae in the SSD of the same MOA herbicides are the same. The 2 parameters of log-normal SSD, mean sensitivity, and variation in sensitivity, for 92 herbicides were determined to establish the estimation model. Mean sensitivities were linearly correlated with logarithmic 50% effect concentrations (EC50) for standard algae. The average of variations in sensitivity significantly differed among MOA, and variations in sensitivity were constant independently of EC50 values for standard algae for the same MOA herbicides. These results were all consistent with the assumptions of the SSD estimation method. The outcome was validated by comparing the estimated SSDs using the proposed method with the generated SSDs using toxicity data which were independent of method development. These SSDs were consistent, and considering MOA information improved the accuracy of estimating SSD markedly.
尽管物种敏感度分布（SSD）是定量生态风险评估的关键概念，但其应用因缺乏足够的分析数据而受到限制，尤其是关于除草剂对初级生产者毒性的数据。作者开发了一种利用单物种毒性数据和除草剂作用模式信息来估算除草剂SSD的方法。作者的方法基于两个假设：同一作用模式除草剂的SSD斜率相同，且同一作用模式除草剂的SSD中标准藻类的相对敏感度相同。确定了92种除草剂的对数正态SSD的两个参数，即平均敏感度和敏感度变化，以建立估算模型。平均敏感度与标准藻类的对数50%效应浓度（EC50）呈线性相关。不同作用模式之间敏感度变化的平均值存在显著差异，对于同一作用模式的除草剂，敏感度变化与标准藻类的EC50值无关且保持恒定。这些结果均与SSD估算方法的假设一致。通过将使用所提出方法估算的SSD与使用独立于方法开发的毒性数据生成的SSD进行比较，对结果进行了验证。这些SSD是一致的，并且考虑作用模式信息显著提高了SSD估算的准确性。
