Trophic fate of inorganic and methyl-mercury in a macrophyte-chironomid food chain

Article Article scientifique Article Trophic fate of inorganic and methyl-mercury in a macrophyte-chironomid food chain eng 2017 author Beauvais-Flueck Rebecca 777564 author Gimbert Frédéric 683794 author Méhault Ophélie 831515 author Cosio Claudia 89306 140-147 10.1016/j.jhazmat.2017.05.028 0304-3894 http://linkinghub.elsevier.com/retrieve/pii/S0304389417303783 Dietary transfer of mercury (Hg) is central for its effects on higher trophic animals, nonetheless, its driving parameters and characteristics are not well understood. Here we measured Hg species transfer (uptake) from the macrophyte Elodea nuttallii −mimicking tissues incorporation in sediments after decay- to Chironomus riparius. Methyl-Hg (MMHg) was more transferable than inorganic Hg (IHg) from plant's intracellular and cell wall compartments. After 10-d-long exposure, MMHg was predominantly found in MMHg form in the cytosolic compartment (S) of chironomids, while IHg showed similar concentrations in S and insoluble debris (P) compartments. After cessation of Hg species exposure (depuration), only MMHg resulted in a bioaccumulation factor >1. Toxicokinetics modelling indicated a demethylation of MMHg in the S fraction and its concomitant storage in the P fraction as IHg during both uptake and depuration, revealing an elimination and detoxification mechanism. Our data support that MMHg is more transferable than IHg to sensitive subcellular targets as well as bioavailable fraction in chironomids, in line with field studies showing higher MMHg transfer than IHg in food webs. Hence our data point out macrophytes as a potential Hg source to benthic food webs to be considered for enhancing aquatic environment protection during phytoremediation programs. Dewey 333.7-333.9 Dewey 550 18 Institut des sciences de l'environnement 0DB 41 Département F.-A. Forel des sciences de l'environnement et de l'eau 153 false 752 Environmental Biogeochemistry and Ecotoxicology Journal of hazardous materials 338 539e6580-7750-4c1a-8d84-cb9d7d759925 Article (Published version) Restricted Beauvais-Flueck_HAZMAT_2017.pdf 881439 application/pdf restrictedAccess Centres et instituts / Institut des sciences de l'environnement Faculté des sciences / Section des sciences de la Terre et de l'Environnement / Département F.-A. Forel des sciences de l'environnement et de l'eau

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Trophic fate of inorganic and methyl-mercury in a macrophyte-chironomid food chain	Journal of hazardous materials			2017	1,025	2

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Méhault, Ophélie