Grupo de Biología y Toxicología Ambiental, Facultad de Ciencias, Universidad Nacional de Educación a Distancia (UNED), Senda del Rey 9, 28040 Madrid, Spain.
Laboratorio de Ecotoxicología, Departamento de Medio Ambiente, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Crta A Coruña Km 7, 28040 Madrid, Spain.
Sci Total Environ. 2018 Nov 15;642:180-189. doi: 10.1016/j.scitotenv.2018.06.054. Epub 2018 Jun 9.
Post-treatment wastewater reuses are diverse. Recreational and environmental restoration uses of reclaimed water (RW) can be potentially harmful to aquatic organisms. In this work the freshwater snail Physa acuta was exposed to RW (100%) and its dilution (RW 50%). A simple laboratory mixture of three emerging pollutants was used to address the complex problem of mixture toxicity of RW. Hence fortified reclaimed water (FRW), obtained by adding fluoxetine (400 μg FLX/L), perfluorooctane sulphonic acid (90 μg PFOS/L) and methylparaben (9 μg MP/L), was tested at two dilution percentages: 100% and 50%. The effects of the laboratory mixture of FLX, PFOS and MP on the test medium were also studied. Long-lasting effects, together with early molecular responses, were assessed. Fecundity (cumulative egg production) over 21 days and the hatching of produced eggs (F1) after another 21-day embryonic exposure were monitored. The gene expression of three genes was analysed after 24 h of exposure: two endocrine-related nuclear receptors (ERR and RXR) and one stress protein gene (Hsp70). This reproduction test, with additional assessments of the F1 recovered eggs' hatching success, showed that both RW and FRW significantly reduced fecundity. F1 hatching was affected only by FRW. The gene expression results showed that the RXR response was strikingly similar to the fecundity response, which suggests that this nuclear receptor is involved in the reproductive pathways of gastropods. ERR remained virtually unaltered. Hsp70 was overexpressed by the laboratory mixture in the test medium, but no effect was observed in the fortification of RW. This opposite effect and lack of response for F1 hatching produced by the laboratory mixture in the test medium highlighted the difficulty of predicting mixture effects. The experimental approach allowed us to test the effects caused by RW on P. acuta at different biological organisation levels. Thus, the combination of molecular biomarkers and ecological relevant endpoints is a good strategy to test complex mixtures like RW as it provides a framework to link mechanisms of action and whole organism effects when it is almost impossible to detect the pollutant(s) that cause toxic effects.
经处理后的废水再利用方式多种多样。再生水（RW）的娱乐和环境修复用途可能对水生生物造成危害。在这项工作中，淡水蜗牛 Physa acuta 暴露于 RW（100%）及其稀释液（RW 50%）中。使用一种新兴污染物的简单实验室混合物来解决 RW 混合物毒性的复杂问题。因此，通过添加氟西汀（400μg FLX/L）、全氟辛烷磺酸（90μg PFOS/L）和对羟基苯甲酸甲酯（9μg MP/L），得到强化再生水（FRW），并在两个稀释率下进行测试：100%和 50%。还研究了实验室混合物 FLX、PFOS 和 MP 对测试介质的影响。评估了长期影响以及早期分子反应。在 21 天的时间里监测了累积产卵量，以及在另一个 21 天的胚胎暴露后产生的卵的孵化（F1）。在暴露 24 小时后分析了三个基因的基因表达：两种内分泌相关核受体（ERR 和 RXR）和一种应激蛋白基因（Hsp70）。这项繁殖测试，以及对回收的 F1 卵孵化成功率的额外评估表明，RW 和 FRW 均显著降低了繁殖力。只有 FRW 影响 F1 的孵化。基因表达结果表明，RXR 反应与繁殖力反应非常相似，这表明该核受体参与了腹足类动物的繁殖途径。ERR 基本不变。Hsp70 在测试介质中被实验室混合物过度表达，但在 RW 的强化中没有观察到。这种相反的效果以及实验室混合物在测试介质中对 F1 孵化产生的无反应突出了预测混合物效应的难度。实验方法使我们能够在不同的生物学组织水平上测试 RW 对 P. acuta 的影响。因此，将分子生物标志物和具有生态相关性的终点相结合是测试 RW 等复杂混合物的一种很好的策略，因为它提供了一个框架，可以将作用机制与整体生物效应联系起来，而当几乎不可能检测到造成毒性效应的污染物时，这是非常有必要的。
