"The use of heavy stable isotopes for tracing the source of Metallic Trace Elements (MTE) in the environment has been well established during the last decade but focused mostly on simple cases (local point source pollutions), while Ag has remained unexploited in this respect. The ISOGIRE project aims at investigating heavy stable Cu, Zn and Ag isotope fractionation in the large scale (80000 km²) and well constrained Gironde continuum (as a model case system). The objective is to use MTE isotopes to identify and discriminate different (diffuse and point) source of pollutions and their evolution in time, accounting for biogeochemical processes (non-conservative behaviour by reactive estuarine mixing and biological uptake by oysters) that may modify their isotopic signatures. The ISOGIRE project relies on a multidisciplinary approach linking metallic trace elements isotope geochemistry, biology/ecotoxicology and mineralogical in situ analysis. The ISOGIRE project will address the recent issue of emerging Ag contamination observed in the Gironde estuary and surface waters worldwide, presumably due to the rise of Ag (and Ag nanoparticles (NP)) in consummer’s goods. A versatile analytical methodology for Ag isotopes measurements by MC-ICP-MS will be developed for various environmental matrices in order to evaluate the possibility of identifying and discriminating Ag and Ag-NP sources and follow their environmental route using their isotopic compositions. In addition of being complementary to the “nanosafetycluster” group, promoting studies on the environmental impact of NP at the European level, the ISOGIRE project is consistent with the priority objectives related to Environment from the work programme with respect to the multidisciplinary approach and development of new monitoring methodologies."