Cleuvers Michael
Chair of Biology II, Department of General Biology, Aachen University of Technology, Kopernikusstrasse 16, D-52056, Aachen, Germany.
Chemosphere. 2005 Apr;59(2):199-205. doi: 10.1016/j.chemosphere.2004.11.090. Epub 2005 Jan 21.
Daphnia magna, Desmodesmus subspicatus and Lemna minor were used to determine the ecotoxicity of beta-blockers. Propranolol was the most toxic substance, with EC50s of 7.7 mg l-1 in the Daphnia test and 0.73 mg l-1 in the algal test. The toxicity of atenolol and metoprolol in the Daphnia test was very low, with EC50s of 313 and 438 mg l-1, respectively. In the algal test, metoprolol (EC50: 7.9 mg l-1) was more toxic than atenolol (EC50: 620 mg l-1). Lemna minor was the least sensitive species. All substances showed PEC/PNEC ratios <1, whereas propranolol with a ratio of 0.81 seems to be the most relevant substance and I recommend to perform chronic biotests to refine the estimate of the environmental risk. Taking bioconcentration factors (BCF) into account, resulting internal effect concentrations (IEC) differ only slightly, which means that the differences in the EC50 depend mainly on the diverse logP levels causing narcosis via disruption of membrane integrity. Predictions of toxicity using ECOSAR were close to the empirically measured data. Mixture toxicity of the three compounds could be predicted accurately using the concept of concentration addition.
大型溞、近尖栅藻和浮萍被用于测定β受体阻滞剂的生态毒性。普萘洛尔是毒性最强的物质，在大型溞试验中的半数有效浓度（EC50）为7.7毫克/升，在藻类试验中为0.73毫克/升。阿替洛尔和美托洛尔在大型溞试验中的毒性非常低，EC50分别为313毫克/升和438毫克/升。在藻类试验中，美托洛尔（EC50：7.9毫克/升）比阿替洛尔（EC50：620毫克/升）毒性更强。浮萍是最不敏感的物种。所有物质的预测环境浓度/预测无效应浓度（PEC/PNEC）比值均<1，而比值为0.81的普萘洛尔似乎是最相关的物质，我建议进行慢性生物试验以完善对环境风险的评估。考虑到生物富集因子（BCF），由此产生的内部效应浓度（IEC）差异不大，这意味着EC50的差异主要取决于通过破坏膜完整性导致麻醉的不同logP水平。使用ECOSAR预测的毒性与实测数据接近。使用浓度加和概念可以准确预测这三种化合物的混合毒性。
