The Loire River is one of the largest river systems in Western Europe and a major source of continental inputs to the marine environment in the Bay of Biscay. Its catchment area drains agricultural and industrial zones and its estuary is increasingly urbanized. Even if the Loire River is not considered as a highly polluted system, studies have shown estuarine Pb contamination due to industrial inputs and combustion of leaded gasoline until the mid 1990’s. A retrospective study, based on the analysis (Pb levels and isotopic composition) of mussel samples collected by the French mussel watch program (RNO/ROCCH) has highlighted this contamination and its trend between 1985-2005 (Couture et al., 2010). This poster furthers the work initiated by Couture et al. Here, Pb levels and isotopic signatures in samples from the environmental sample bank from RNO/ROCCH over the last 10 years will be presented and confronted to measurements of other environmental samples.