The BIOPACA project is intended for the study of fate and effects of the most commonly used anionic surfactants (Linear alkylbenzene sulfonates: LAS) present in household cleaning detergents. Despite their high biodegradability, their constant discharge in costal areas with urban effluent lead to detect a sufficiently high background concentration to raise concern about its toxicity for marine ecosystems. Within this framework, BioPACA project objectives are threefold: (1) draw up a state of knowledge about the contamination and the impact of these organic compounds on the marine ecosystem (water, sediment and the marine mussel, Mytilus galloprovincialis), with the Golfe-Juan bay (France) as pilot site because a biological treatment will be soon operational. A cartography of LAS contamination will be performed along the French coast (via biomonitoring programme Rinbio 2009 - Ifremer) in order to assess the distribution of LAS in seawater, sediments and in the mediterranean mussels - used as a sentinel species; (2) develop a methodology for the extraction, preconcentration, purification, identification and quantification of the different LAS congeners and their metabolites in seawater, sediments and tissue from living organisms; and (3) identify biomarkers to assess subcellular toxicity of LAS accumulated in marine organisms. Scientific results will enable to complete the knowledge of fate, behaviour, distribution, bioaccumulation, toxicity and depollution of LAS in the different marine coastal compartments, that is a crucial need in risk assessment for the new european legislation REACH.