In the present study, we assessed the ecotoxicological effects of selected human and veterinary antibiotics to D. magna. Ecological risk assessment was done by calculating the risk quotients (RQs) of the antibiotics to the species. Results showed that enrofloxacin, a veterinary fluoroquinolone antibiotic, was the most toxic against D. magna with a 48 h EC₅₀ value of 28.59 mg/l. The binary mixture of fluoroquinolones was also more toxic to the species than binary mixtures of macrolides. Fecundity in organisms in negative control was higher than fecundity in organisms exposed to environmentally relevant concentrations of the four antibiotics. Enrofloxacin also has a moderate risk to the species with RQ values of 0.199 and 0.416 in surface waters and wastewaters, respectively. Antibiotics pose a greater ecological risk when present in mixtures in the aquatic environment. Environmental standards for pharmaceuticals should incorporate mixture toxicity data to ensure accurate protection of non-target organisms in polluted environments.

在本研究中，我们评估了选定的人用和兽用抗生素对D. magna 的生态毒理学影响。通过计算抗生素对物种的风险商（RQs）来进行生态风险评估。结果表明，兽用氟喹诺酮类抗生素恩诺沙星对D. magna毒性最大，48 小时 EC ₅₀值为 28.59 毫克/升。与大环内酯类的二元混合物相比，氟喹诺酮类的二元混合物对该物种的毒性也更大。阴性对照生物体的繁殖力高于暴露于环境相关浓度的四种抗生素的生物体的繁殖力。恩诺沙星对地表水和废水中 RQ 值分别为 0.199 和 0.416 的物种也有中等风险。当抗生素以混合物形式存在于水生环境中时，会带来更大的生态风险。药品环境标准应包含混合物毒性数据，以确保准确保护污染环境中的非目标生物。