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Impacts environnementaux des agents de contraste à base de Gadolinium : situation locale, approche cellulaire et in vivo

Abstract : The increasing use of Gadolinium-based Contrast Agents (Gd-CA) for Magnetic Resonance Imaging (MRI) results in their rejection in Waste Water Treatment Plants (WWTPs). Due to the lack of specific recycling process in European WWTPs, these pharmaceutical produces enter the aquatic environment from river to tap water. The effects of Gd-CA in aquatic media have been not studied yet. The lack of knowledge about these effects highlighted the need to study their environmental impacts on aquatic organisms. In this context, we decided to measure anthropogenic concentrations of Gd in the aquatic environment in the Lorraine region (France) closed to WWTPs outputs and catchment areas used for drinking water. Our measurements underlined the presence of anthropogenic Gd on all the collected samples at concentrations ranging from few ng/L to several dozen of µg/L. In this research we focused on the effects of the most frequently used Gd-CA, the gadoteric acid (Gd-DOTA - Dotarem®) which is also the most stable one. Several representative species of aquatic environment were selected for ecotoxicological assays: i.e. unicellular green microalgae (Chlorella vulgaris and Pseudokirchneriella subcapitata), microcrustacean (Daphnia magna) and aquatic vertebrate (Danio rerio). Assays were conducted in laboratory under controlled conditions as well as in situ. Gd-DOTA accumulation was measured in the tissues of the different organisms. Environmental realistic concentrations of Gd-CA were used to assess their effects at the individual level by means of growth, reproduction and mortality measurements. The Gd-DOTA accumulation was also measured in bivalves’ tissues (Corbicula fluminea and Dresseina rostriformis bugensis) and compared to Gd ones in situ in these organisms. Physiological responses were assessed based on a battery of 11 complementary biomarkers measured in the digestive gland and in the gills of both bivalve species. At cellular level, the effects of Gd-DOTA were studied in vitro on D. rerio fibroblasts (ZF4 – ATCC-2050). Indirect ecotoxicological effects of Gd-CA and of Gd-DOTA especially have been highlighted at all biological levels. Accumulation of Gd-DOTA was observed in bivalves only, but defense systems were mobilized in all organisms to limit toxicity. Our results demonstrated that following both research on ecotoxicological effects of the Gd-CA and evolution of their concentrations in aquatic ecosystem are necessary to assess more precisely their environmental risk and to propose solutions for their environmental management
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Submitted on : Friday, June 8, 2018 - 12:02:18 PM
Last modification on : Friday, September 18, 2020 - 6:10:04 PM
Long-term archiving on: : Sunday, September 9, 2018 - 2:15:12 PM

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  • HAL Id : tel-01810871, version 1

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Emilie Perrat. Impacts environnementaux des agents de contraste à base de Gadolinium : situation locale, approche cellulaire et in vivo. Ecosystèmes. Université de Lorraine, 2017. Français. ⟨NNT : 2017LORR0370⟩. ⟨tel-01810871⟩

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