Abstract

Widely dispersed in aquatic environments, metals or Trace Metal Elements (TMEs) such as cadmium (Cd) or zinc (Zn) are monitored in waters, due to their toxicity, as defined by the Water Framework Directive (WFD). However, the derived indicators do not informed on the bioaccumulation and integration of these metals in living organisms. The use of bioindicator species in this monitoring integrates all processes including biotic or abiotic variables that determine the bioavailability and accumulation of metals by organisms. Gammarids are widely used for biomonitoring, particularly on the basis of contaminant concentrations measured in organisms. Until now, however, studies of the bioaccumulation of TMEs in this organism have been carried out mainly at the level of the whole organism and there are very few data at the level of tissues/organs. These data are essential to understand the complexity of the processes governing bioaccumulation. In the work presented in this manuscript, we sought, in male gammarids of the species Gammarus fossarum, to improve the understanding of metal bioaccumulation by seeking to: i) study the organotropism of metals; ii) understand the role of organs in metal bioaccumulation; iii) study the ADME (Absorption/Assimilation, Distribution, "Metabolization/Methylation" and Elimination) processes governing the handling and fate of metals; and iii) find out if factors such as the pathway of accumulation, the essentiality or non-essentiality, or finally the concentration of exposure have an influence on bioaccumulation processes. For this purpose, a specific experimental protocol was set up, coupling sensitive radiotracer tools to follow the accumulation and elimination of TMEs, to one- and/or multi-compartment toxicokinetic models coupled to Bayesian inference to formalize the internal fate of TMEs. The results show that organotropism, toxicokinetics and fate of metals are specific: i) to the metal itself, showing different bioaccumulation patterns between Cd, mercury (Hg), and Zn, independent of the essential or non-essential character of the metal; ii) to the accumulation pathway, showing a very high concentration of Cd in the gills after accumulation by the trophic pathway and an absence of accumulation in this same organ by the trophic pathway. However, the work presented here did not demonstrate an influence of Cd exposure concentration on organotropism, ADME processes or Cd fate in gammarids. This preliminary work could help improve the accuracy of results obtained via TKTD models, used in environmental risk assessment, by helping to develop and include a real TK part.

Funding

ANR APPROve Project

Publications and communications

• Ophélia Gestin, Christelle Lopes, Nicolas Delorme, Laura Garnero, Olivier Geffard, et al.. Organ–specific accumulation of cadmium and zinc in Gammarus fossarum exposed to environmentally relevant metal concentrations. Environmental Pollution, 2022, 308, pp.119625. ⟨10.1016/j.envpol.2022.119625⟩. ⟨hal–03827574⟩
• Ophélia Gestin, Thomas Lacoue–Labarthe, Nicolas Delorme, Laura Garnero, Olivier Geffard, et al.. Influence of the exposure concentration of dissolved cadmium on its organotropism, toxicokinetic and fate in Gammarus fossarum. Environment International, 2023, 171, pp.107673. ⟨10.1016/j.envint.2022.107673⟩. ⟨hal–04221474⟩
• Ophélia Gestin, Olivier Geffard, Nicolas Delorme, Laura Garnero, Thomas Lacoue–Labarthe, et al.. Bioaccumulation, organotropism and fate of cadmium in Gammarus fossarum exposed through dietary pathway. Journal of Hazardous Materials, 2024, 480, pp.135965. ⟨10.1016/j.jhazmat.2024.135965⟩. ⟨hal–04715727⟩
• Sandrine Charles, Ophelia Gestin, Jérémie Bruset, Dominique Lamonica, Virgile Baudrot, et al.. Generic Solving of Physiologically–based Kinetic Models in Support of Next Generation Risk Assessment Due to Chemicals. Journal of Exploratory Research in Pharmacology, 2022, 8 (2), pp.140–154. ⟨10.14218/JERP.2022.00043⟩. ⟨hal–04468979⟩
• Ophélia Gestin, Christelle Lopes, Nicolas Delorme, Laura Garnero, Olivier Geffard, et al.. Assimilation efficiencies and elimination rates of silver, cadmium and zinc accumulated by trophic pathway in Gammarus fossarum. Peer Community Journal, 2024, 4, pp.e51. ⟨10.24072/pcjournal.426⟩. ⟨hal–04593486⟩
• Ophélia Gestin, Thomas Lacoue–Labarthe, Marina Coquery, Nicolas Delorme, Laura Garnero, et al.. One and multi–compartments toxico–kinetic modeling to understand metals’ organotropism and fate in Gammarus fossarum. Environment International, 2021, 156, pp.106625. ⟨10.1016/j.envint.2021.106625⟩. ⟨hal–03343406⟩
• Matteo Riccardo Di Nicola, Irene Cattaneo, Alexis Nathanail, Edoardo Carnesecchi, Maria Chiara Astuto, et al.. The use of new approach methodologies for the environmental risk assessment of food and feed chemicals. Current Opinion in Environmental Science & Health, 2023, 31, pp.100416. ⟨10.1016/j.coesh.2022.100416⟩. ⟨hal–04468997⟩

Key words

ADME processes, Bayesian inference, Multi-Compartment TK models, One-Compartment TK models, Organs, Bioaccumulation, Metals, Invertebrates

Cite the thesis

Ophélia Gestin. Organotropisme, toxico-cinétique et devenir des contaminants métalliques chez une espèce sentinelle d’eau douce Gammarus fossarum. Ecologie, Environnement. Université Claude Bernard - Lyon I, 2022. Français. ⟨NNT : 2022LYO10170⟩. ⟨tel-04368960⟩

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