Pharmaceutical residues and other micro-contaminants may enter aquatic environments through effluent from sewage treatment plants (STPs) and could cause adverse effects in wild fish. One strategy to alleviate this situation is to improve wastewater treatment by ozonation. To test the effectiveness of full-scale wastewater effluent ozonation at a Swedish municipal STP, the added removal efficiency was measured for 105 pharmaceuticals. In addition, gene expression, reproductive and behavioral endpoints were analyzed in zebrafish (Danio rerio) exposed on-site over 21 days to ozonated or non-ozonated effluents as well as to tap water. Ozone treatment (7 g O₃/m³) removed pharmaceuticals by an average efficiency of 77% in addition to the conventional treatment, leaving 11 screened pharmaceuticals above detection limits. Differences in biological responses of the exposure treatments were recorded in gene expression, reproduction and behavior. Hepatic vitellogenin gene expression was higher in male zebrafish exposed to the ozonated effluent compared to the non-ozonated effluent and tap water treatments. The reproductive success was higher in fish exposed to ozonated effluent compared to non-ozonated effluent and to tap water. The behavioral measurements showed that fish exposed to the ozonated STP effluent were less active in swimming the first minute after placed in a novel vessel. Ozonation is a capable method for removing pharmaceuticals in effluents. However, its implementation should be thoroughly evaluated for any potential biological impact. Future research is needed for uncovering the factors which produced the in vivo responses in fish.

药物残留物和其他微污染物可能通过污水处理厂（STP）的废水进入水生环境，并可能对野生鱼造成不利影响。缓解这种情况的一种策略是通过臭氧化改善废水处理。为了测试在瑞典市政STP上进行大规模废水排放臭氧化的有效性，测量了105种药品的附加去除效率。此外，分析了在21天现场暴露于臭氧化或非臭氧化废水以及自来水的斑马鱼（Danio rerio）中的基因表达，生殖和行为终点。臭氧处理（7 g O ₃ / m ³）除常规处理方法外，以平均77％的效率去除了药物，使11种经过筛选的药物超过了检测极限。在基因表达，繁殖和行为方面记录了暴露处理的生物学反应差异。与非臭氧化废水和自来水处理相比，暴露于臭氧化废水中的雄性斑马鱼肝卵黄蛋白原基因表达更高。与非臭氧水和自来水相比，接触臭氧水的鱼的繁殖成功率更高。行为测量表明，暴露于臭氧处理过的STP废水中的鱼在放入新型容器后的第一分钟内游泳活动较少。臭氧化是一种去除废水中药物的有效方法。然而，应彻底评估其实施是否有任何潜在的生物学影响。为了发现在鱼类中产生体内反应的因素，需要进行进一步的研究。