Transfer, Transformation, and Impacts of Ceria Nanomaterials in Aquatic Mesocosms Simulating a Pond Ecosystem

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• 作者：Tella Marie ; Auffan M茅lanie ; Brousset Lenka ; Issartel Julien ; Kieffer Isabelle ; Pailles Christine ; Morel Elise ; Santaella Catherine ; Angeletti Bernard ; Artells Ester ; Rose J茅r么me ; Thi茅ry Alain ; Bottero Jean-Yves
• 刊名：Environmental Science & Technology
• 出版年：2014
• 出版时间：August 19, 2014
• 年：2014
• 卷：48
• 期：16
• 页码：9004-9013
• 全文大小：392K
• ISSN：1520-5851

文摘

Mesocosms are an invaluable tool for addressing the complex issue of exposure during nanoecotoxicological testing. This experimental strategy was used to take into account parameters as the interactions between the NPs and naturally occurring (in)organic colloids (heteroaggregation), or the flux between compartments of the ecosystems (aqueous phase, sediments, biota) when assessing the impacts of CeO₂ NPs in aquatic ecosystems. In this study, we determine the transfer, redox transformation, and impacts of 1 mg L^鈥? of bare and citrate coated CeO₂鈥揘Ps toward an ecologically relevant organism (snail, Planorbarius corneus) exposed 4 weeks in a complex experimental system mimicking a pond ecosystem. Over time, CeO₂鈥揘Ps tend to homo- and heteroaggregate and to accumulate on the surficial sediment. The kinetic of settling down was coating-dependent and related to the coating degradation. After 4 weeks, Ce was observed in the digestive gland of benthic organisms and associated with 65鈥?0% of Ce^IV reduction into Ce^III for both bare and coated CeO₂ NPs. A transitory oxidative stress was observed for bare CeO₂鈥揘Ps. Coated-NPs exposed snails did not undergo any lipid peroxidation nor change in the antioxidant contents, while Ce content and reduction in the digestive gland were identical to bare CeO₂鈥揘Ps. We hypothesized that the presence of citrate coating enhanced the defense capacity of the cells toward the oxidative stress induced by the CeO₂ core.