Acute and chronic toxicity of the benzodiazepine diazepam to the tropical crustacean Mysidopsis juniae

Abstract Pharmaceuticals occur in the environment due to their excessive consumption and the inefficiency of treatment plants to degrade, inactivate or remove them. Diazepam (DZP) stands out as the most consumed benzodiazepine, and induces sedative effects and reduces anxiety. Considering its potential appearance in several environmental compartments, the aim of the present study was to determine the effects of DZP under acute and chronic exposures on the mysid Mysidopsis juniae. Mortality was assessed using an acute toxicity test and a LC50 of 3.7 ± 0.5 mg·L-1was derived. The mass and length of the mysids was recorded in the chronic exposure to test for sublethal effects, and concentrations of 0.25 and 0.5 mg·L-1 of DZP affected mysids length and dry weight, respectively. Although effect-inducing concentrations used in this study are above environmentally relevant levels, the present study adds value to the limited available data for DZP toxicity to marine organisms, and we have shown that M. juniae is the most sensitive marine crustacean species tested thus far.

摘要 药物因过度消费以及污水处理厂无法有效降解、灭活或去除它们，而持续存在于环境中。地西泮（Diazepam, DZP）是目前使用量最高的苯二氮䓬类药物，具有镇静作用并可缓解焦虑。鉴于其可能在多种环境介质中出现，本研究旨在探究地西泮对糠虾（Mysidopsis juniae）的急性与慢性暴露毒性效应。本研究通过急性毒性试验评估了死亡率，得出半致死浓度（LC50）为3.7 ± 0.5 mg·L⁻¹。在慢性暴露试验中，通过记录糠虾的体质量与体长以评估亚致死效应，结果显示0.25 mg·L⁻¹与0.5 mg·L⁻¹的地西泮分别对糠虾的体长和干重产生影响。虽然本研究中所用的效应诱导浓度高于实际环境中的相关浓度水平，但本研究为有限的地西泮对海洋生物毒性的现有数据补充了新的参考价值；同时本研究证实，糠虾（M. juniae）是目前已测试的最为敏感的海洋甲壳类物种。