Historical sedimentary deposition and flux of PAHs, PCBs and DDTs in sediment cores from the western Adriatic Sea

The sources and depositional history of polycyclic aromatic hydrocarbons (PAHs) and organochlorine compounds (OCs) over the last century were investigated in sediment cores from the North Adriatic Sea (Po River prodelta) and the South-Western Adriatic Margin (SWAM). Contaminant concentrations were higher in the Po River prodelta. 1116PAHs ranged from 193 to 533 ng g 121, 115PCBs ranged from 0.9 to 5.2 ng g 121 and 11DDTs (p,p\u2032-DDD + p,p\u2032-DDE) ranged from 0.1 to 2.5 ng g 121. In the SWAM, 11PAHs ranged from 11 to 74 ng g 121 while 11PCB and 11DDT concentrations were close to the MQL. Accordingly, contaminant fluxes were much higher in the northern (mean values of 152 \ub1 31 ng cm2 y 121 and 0.70 \ub1 0.35 ng cm2 y 121 for PAHs and OCs, respectively) than in the southern Adriatic (2.62 \ub1 0.9 ng cm2 y 121 and 0.03 \ub1 0.02 ng cm2 y 121 for PAHs and OCs, respectively). The historical deposition of PAHs seemed to be influenced by the historical socioeconomic development and by changes in the composition of fossil fuel consumption (from petroleum derivatives to natural gas) in Italy from the end of the 19th century to the present. Similarly, vertical variations in DDT concentrations matched its historical use and consumption in Italy, which started around in the mid-late 1940s to fight typhus during the II World War. Contaminant concentrations detected in sediments does not seem to pose ecotoxicological risk for marine organisms in the Adriatic Sea