Pharmaceutical substances are ubiquitous in the aquatic environment and their concentration levels typically range from ng/L up to several μg/L. Furthermore, as those compounds are designed to be highly biologically active, assessing their impacts on non-target organisms is important. Here, we conducted a mesocosm experiment testing a mixture of five pharmaceuticals (diclofenac, carbamazepine, irbesartan, acetaminophen and naproxen) on fish, three-spined stickleback (Gasterosteus aculeatus). The mixture concentration levels were chosen on the basis of the contamination of the Meuse river in Belgium which had been measured previously during a monitoring campaign undertaken in 2015 and 2016. Three nominal mixture concentration levels were tested: the lowest concentration level mixture was composed by environmentally-relevant concentrations that approximate average realistic values for each pharmaceuticals (Mx1); the two other levels were 10 and 100 times these concentrations. Although no impact on stickleback prey was observed, the mixture significantly impaired the survival of female fish introduced in the mesocosms at the highest treatment level without causing other major differences on fish population structure. Impacts on condition factors of adults and juveniles were also observed at both individual and population levels. Using a modelling approach with an individual-based model coupled to a bioenergetic model (DEB-IBM), we concluded that chronic exposure to environmentally-relevant concentrations of five pharmaceuticals often detected in the rivers did not appear to strongly affect the three-spined stickleback populations. Mechanisms of population regulation may have counteracted the mixture impacts in the mesocosms.

中文翻译：

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长期接触药物混合物对抽搐中观人群三旋棘背（gasterosteus aculeatus）种群动态的影响。

药物物质在水生环境中无处不在，其浓度水平通常在ng / L到几μg/ L之间。此外，由于这些化合物被设计为具有高生物活性，因此评估其对非目标生物的影响非常重要。在这里，我们进行了一项介观试验，测试了鱼，三刺棘背鱼（Gasterosteus aculeatus）中五种药物（双氯芬酸，卡马西平，厄贝沙坦，对乙酰氨基酚和萘普生）的混合物。根据比利时默兹河的污染来选择混合物的浓度水平，该污染先前已在2015年和2016年进行的监测活动中进行了测量。测试了三种名义混合物浓度：最低浓度水平的混合物由与环境相关的浓度组成，这些浓度近似于每种药物的平均实际值（Mx1）；其他两个水平分别是这些浓度的10倍和100倍。尽管未观察到对stick背猎物的影响，但该混合物显着损害了以最高处理水平引入到中膜的雌鱼的存活，而没有对鱼类种群结构造成其他重大差异。在个人和人口水平上也观察到对成人和青少年条件因素的影响。通过结合基于个体的模型和生物能模型（DEB-IBM）的建模方法，我们得出的结论是，长期暴露于河流中经常检测到的与环境有关的五种药物浓度似乎并没有强烈影响三棘背le种群。人口调节机制可能抵消了混合物对中观的影响。