Résumé
Parent compounds and metabolites excreted in wastewater are inconstantly eliminated in WTPs and therefore are rejected mainly in surface water. However, the coastal environment suffers from pollution generated by inland activities which discharge their wastes into the sea via streams, rivers and wastewater marine outfalls. The low levels reported in the marine environment encourage the development of adapted methodologies to estimate predicted environmental concentrations (PECs). In the present work, the occurrence of VLF and its major human metabolites was investigated at a Mediterranean coastal site directly impacted by a submarine outfall. Concentrations of VLF and its metabolites were measured in the different compartments i.e. in water with passive sampler, sediment and mussels. Predicted concentrations of VLF and its main human metabolites were estimated in seawater taking into account the sold amounts of VLF, its human metabolism and the diffusion and dilution of the compounds in the coastal zone using an adapted hydrodynamic model (MARS 3D) developed by Ifremer. In seawater, estimated concentrations were in a good agreement with measured levels. Moreover, concentrations in mussels were estimated using concentrations estimated in seawater and a bioconcentration factor (BCF) linear model described in the literature for marine mussels. Estimated concentrations in biota were then compared to the concentrations in mussels detected at the studied site. Concentrations estimated with the BCF model were overestimated compared to measured concentrations, which could be explained by a possible metabolism of these compounds by mussels, not taken into account in the estimations. Moreover, attenuation mechanisms such as sorption on suspended matter could explain a lower availability of compounds for mussels in the water column and a lower bioconcentration in organisms than those expected. Studies on sorption mechanismsand metabolism of these compounds in mussels should be further performed, in order to improve these estimations. As organisms are long-term exposed to low concentrations of pharmaceuticals, possible effects could be observed. The use of sensitive approaches, such as “omics” approaches, already used for other pollutants such as heavy metals, could help obtain this information.