Université de Lyon, ENTPE, CNRS, UMR 5023 LEHNA, 2 Rue Maurice Audin, 69518 Vaulx-en-Velin, France; Université de Lyon, INSA-Lyon, DEEP - EA 7429, 9 rue de la Physique, F69621 Villeurbanne Cedex, France.
Université de Lyon, ENTPE, CNRS, UMR 5023 LEHNA, 2 Rue Maurice Audin, 69518 Vaulx-en-Velin, France.
Chemosphere. 2019 Feb;217:522-533. doi: 10.1016/j.chemosphere.2018.11.033. Epub 2018 Nov 13.
Urban wet weather discharge (UWWD) management is an important issue. UWWD often represents a significant source of pollution in all aquatic bodies. The occurrence of this pollution is difficult to predict due to the variability of storm events and the unknown contents of urban watershed leached out by rain. Previous studies have tried to demonstrate the ecotoxic impact of UWWD. However, most of them merely highlight the limitations of classic monospecific bioassays, given the high dilution of micropollutants or the presence of nutrients masking toxic effects. Overcoming this problem is therefore of great interest. In this study, we demonstrated the utility of a battery of biomarkers (e.g. membrane permeability, chlorophyll fluorescence, esterase and alkaline phosphatase activities) on the microalgae Chlorella vulgaris to detect the toxic effects of 7 UWWD samples after short exposures (2 and 24 h). These biomarkers are linked to microalgal life traits. Complementarily, monospecific bioassays were carried on Pseudokirchneriella subcapitata, Chlorella vulgaris, Daphnia magna and Heterocypris incongruens to compare their sensitivity to the UWWD samples. No toxic effect was detected in any of the bioassays. Yet, algal biomarkers indicated a disturbance in microalgae physiology, and particularly a perturbation of chlorophyll fluorescence, which was observed in all of the samples tested. While algal membrane permeability was affected by only one UWWD, these two enzymatic activities were stimulated or inhibited depending on the sample. Finally, this study demonstrates the sensitivity of algal biomarkers and the need to develop new, fruitful approaches to characterizing UWWD toxicity.
城市雨洪排放（UWWD）管理是一个重要问题。UWWD 通常是所有水体中污染的重要来源。由于暴雨事件的可变性和雨水淋滤出的城市流域中未知的物质含量，这种污染的发生很难预测。先前的研究试图证明 UWWD 的生态毒性影响。然而，由于微污染物的高稀释度或营养物质掩盖了毒性效应，大多数研究仅强调了经典单物种生物测定的局限性。因此，克服这一问题具有重要意义。在本研究中，我们展示了一系列生物标志物（例如膜通透性、叶绿素荧光、酯酶和碱性磷酸酶活性）在小球藻（Chlorella vulgaris）上的应用，以检测 7 种 UWWD 样品在短时间暴露（2 和 24 小时）后的毒性效应。这些生物标志物与微藻的生命特征相关。此外，还对拟菱形藻（Pseudokirchneriella subcapitata）、小球藻（Chlorella vulgaris）、大型溞（Daphnia magna）和霍氏异尾轮虫（Heterocypris incongruens）进行了单物种生物测定，以比较它们对 UWWD 样品的敏感性。在任何生物测定中都未检测到毒性效应。然而，藻类生物标志物表明藻类生理受到干扰，特别是叶绿素荧光受到干扰，在所有测试的样品中都观察到这种情况。虽然藻类膜通透性仅受一种 UWWD 的影响，但这两种酶活性根据样品的不同而受到刺激或抑制。最后，本研究证明了藻类生物标志物的敏感性，并需要开发新的、富有成效的方法来表征 UWWD 毒性。
