Occurrence of an anthropogenic gadolinium anomaly in river and coastal waters of southern France.

This study reports a pronounced positive Gd anomaly in a small river and in the largest French Mediterranean lagoon. Along the studied catchment, this anomaly is also present in the effluents of the municipal sewage treatment plants, suggesting an anthropogenic origin for the Gd excess. The anomaly corresponds to a distinct increase of Gd concentrations (up to 19 pmol/l) in the river and around 5.4 pmol/l in the lagoon. The excess flux of Gd is compatible with the medical use of water soluble Gd complexes as contrasting agent in magnetic resonance imaging.