Krogh Kristine A, Jensen Gitte G, Schneider Manuel K, Fenner Kathrin, Halling-Sørensen Bent
Copenhagen University, Faculty of Pharmaceutical Science, Department of Pharmaceutics and Analytical Chemistry, Section of Toxicology and Environmental Chemistry, Universitetsparken 2, DK-2100 Copenhagen, Denmark.
Chemosphere. 2009 May;75(8):1097-104. doi: 10.1016/j.chemosphere.2009.01.015. Epub 2009 Feb 13.
The study target was to assess the usefulness of the OECD test guideline 307 for the veterinary pharmaceutical ivermectin. Laboratory microcosm studies were conducted to investigate the aerobic and anaerobic transformation of ivermectin in soils from three locations in Europe (York, Madrid and Tåstrup) and an artificial soil. The reason to include an artificial soil in the study was to understand the exposure potential of ivermectin in a parallel eco-toxicological study with non-target organisms in this soil for a longer duration. Three kinetic models (first-order (SFO), availability-adjusted first-order (AAFO) and bi-exponential first-order (BFO)) were applied to fit the observed transformation dynamics and to derive dissipation times. Dissipation rates were highly dependent on the tested soils. Under aerobic conditions, dissipation was remarkably faster in the three natural soils tested (DT(50)=16.1-36.1d) than in the artificial soil (DT(50)>500d). Furthermore, a clear increase in DT(50) values was seen when the temperature was lowered from 20 to 6 degrees C. The results indicated that dissipation in soils with comparably strong sorption and low degrees of desorption (i.e. the York soil and to some extent the Tåstrup soil) were best described by the AAFO model. While dissipation in the Madrid soil which had a lower sorption coefficient and a higher degree of reversibility of sorption could be satisfactorily described with the SFO model. Our data further showed that no significant dissipation occurred under anaerobic conditions.
该研究的目标是评估经合组织（OECD）测试指南307对兽用药物伊维菌素的适用性。开展了实验室微观世界研究，以调查伊维菌素在欧洲三个地点（约克、马德里和塔斯特鲁普）的土壤以及一种人工土壤中的好氧和厌氧转化情况。在研究中纳入人工土壤的原因是，为了在一项针对该土壤中非靶标生物的平行生态毒理学研究中，更长时间地了解伊维菌素的暴露潜力。应用了三种动力学模型（一级动力学模型（SFO）、可用性调整一级动力学模型（AAFO）和双指数一级动力学模型（BFO））来拟合观察到的转化动态，并得出消散时间。消散速率高度依赖于所测试的土壤。在好氧条件下，三种测试的天然土壤中的消散速度明显快于人工土壤（DT(50)=16.1 - 36.1天）（人工土壤的DT(50)>500天）。此外，当温度从20℃降至6℃时，DT(50)值明显增加。结果表明，对于吸附较强且解吸程度较低的土壤（即约克土壤，在某种程度上还有塔斯特鲁普土壤）中的消散情况，AAFO模型的描述最为合适。而对于吸附系数较低且吸附可逆性较高的马德里土壤中的消散情况，SFO模型能够给出令人满意的描述。我们的数据还表明，在厌氧条件下没有发生明显的消散。
