Assessment of the Mediterranean sediments contamination by persistent organic pollutants

13 pages, 6 figures, 4 tables.-- PMID: 17291652 [PubMed].-- Printed version published Jul 2007.A compilation of information about levels of selected persistent organic pollutants, namely polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroetane and its degradation products (DDTs) and hexachlorobenzene (HCB), in Mediterranean sediments, including data published from 1971 to 2005, has been conducted in order to assess their main drivers and pressures in the environment. The application of mapping tools GIS) and statistical instruments enabled the assessment of geographical and temporal trends. Chemical contamination mainly originates from land-based sources, and decreases significantly when moving off-shore. Contamination hot spots are generally located along the Northern coastline. The data for open sea sediments enabled the establishment of background levels of contamination for the region. A decreasing temporal trend in concentrations was found, more evident in the case of DDTs probably due to a more efficient regulation of this chemical. Finally, some gaps in reliable data were also identified which were related to the lack of information in the southern and eastern parts of the Mediterranean as well as the variety of analytical methodologies used.Key information for policy decision makers is provided on the levels of certain POPs in Mediterranean sediments.The European Commission (Research Directorate General - Environment Program) supported this study through the ELME project "European Lifestyles and Marine Ecosystems" (Contr. No. GOCE-CT-2003-505576). One of us (A.G.) wishes to acknowledge the Government of Catalonia for awarding her a PhD fellowship.Peer reviewe