Lead accumulation in oyster shells, a potential tool for environmental monitoring

Pb/Ca profiles were measured on ten live collected Ostrea edulis from three sites characterized by different levels of lead content. Intra-shell and inter-shell reproducibility were tested comparing several Pb/Ca profiles measured by LA-ICP-MS within a specimen, and within specimens from the same site. Results indicate that signals recorded are reproducible and mean shell Pb/Ca values are site-dependent. Second order variability is explained either by smoothing effects, biological effects or micro-environmental heterogeneities in lead distribution. Mean Pb contents measured in marine bivalve shells are reviewed here. Ranging from 0 to 50ppm, they show a strong relationship with the environmental level of local lead contamination, and do not appear species-dependent. Our measurements show a linear relationship between mean shell Pb/Ca and surface sediment Pb concentrations, making marine bivalves and particularly O. edulis a potential accurate bio-monitoring tool able to monitor bioavailable lead along European coasts since Mesolithic, with an annual resolution. •LA-ICP-MS continuous line scans show large annual variations in shell lead content.•Intra- and inter-shell reproducibility of signals was established in each site.•Mean values obtained are clearly site-dependent.•Mean shell lead content and surface sediments lead content are correlated.•Ostrea edulis is a potential bio-monitoring tool of coastal bioavailable lead.