Junker Thomas, Alexy Radka, Knacker Thomas, Kümmerer Klaus
ECT Oekotoxikologie GmbH, Boettgerstrasse 2-14, D-65439 Floersheim, Germany.
Environ Sci Technol. 2006 Jan 1;40(1):318-24. doi: 10.1021/es051321j.
For all new pharmaceuticals, an environmental risk assessment (ERA) has to be performed according to guidelines developed by the European Medicines Evaluation Agency. An important factor of this procedure is the assessment of the predicted environmental concentration in the aquatic environment, which is significantly influenced by the biodegradability of pharmaceuticals in sewage treatment plants. Established standardized methods for determining biodegradation under laboratory conditions apply to substance concentrations, which are much higherthan those expected in reality. Against this background, the laboratory scale sewage treatment plant (LSSTP), as described by the Organisation for Economic Cooperation and Development (OECD) Guideline No. 303A, was modified to construct a lossless system, which allows laboratory testing at realistic concentrations. To verify the experimental setup, the antibiotics benzylpenicillin, ceftriaxone, and trimethoprim were tested at low concentrations (microg/L) using 14C-labeled compounds. The results show that approximately 25% of benzylpenicillin was mineralized, whereas ceftriaxone and trimethoprim were not mineralized at all. Due to the high total recoveries of added radioactivity (> or =95%) and the fact that the findings comply with available literature data, the lossless operation of the test system could be proved. Consequently, the modified LSSTP is a suitable tool to determine more realistic biodegradation data required for the exposure assessment within the scope of an ERA for pharmaceuticals.
对于所有新的药品，必须根据欧洲药品评估局制定的指南进行环境风险评估（ERA）。该程序的一个重要因素是评估水生环境中的预测环境浓度，这受到药品在污水处理厂中生物降解性的显著影响。在实验室条件下确定生物降解的既定标准化方法适用于比实际预期浓度高得多的物质浓度。在此背景下，按照经济合作与发展组织（OECD）第303A号指南所述，对实验室规模的污水处理厂（LSSTP）进行了改进，以构建一个无损系统，该系统允许在实际浓度下进行实验室测试。为了验证实验装置，使用14C标记的化合物对低浓度（微克/升）的抗生素苄青霉素、头孢曲松和甲氧苄啶进行了测试。结果表明，约25%的苄青霉素被矿化，而头孢曲松和甲氧苄啶根本没有被矿化。由于添加放射性的总回收率很高（≥95%），且研究结果与现有文献数据相符，因此可以证明测试系统的无损运行。因此，改进后的LSSTP是一种合适的工具，可用于确定药品ERA范围内暴露评估所需的更实际的生物降解数据。
