Distribution of organic pollutants in surface sediments from Aegean coast

Organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs) and aliphatic hydrocarbons (TALI) were determined in fourteen surface sediment with three replicates collected from the Eastern Aegean coast in 2008. Total concentrations of OCPs, PCBs, PAHs and TALI in sediments ranged from bdl to 17.8, bdl to 26.1, 73.5 to 2170 and 330 to 2660 ng/g dwt, respectively. The results indicated that the DDTs were the predominant contaminant in sediments. p,p?-DDE was the most often found OCP at all stations except Dardanelles Strait Entrance. DDTs in sediments may be derived from the aged and weathered agricultural soils and transported by surface run off from the rivers. OCPs and PCBs were present in noticeably higher concentrations at Izmir Inner Bay than the other sites. According to established sediment quality guidelines, DDTs at four sites and heptachlor at two sites would be more concerned for the ecotoxicological risk in the Eastern Aegean. In addition, the risk of adverse biological effects from the levels of PCBs at sites Candarli Bay and Izmir Inner Bay should be significant.Both pyrolytic and petrogenic PAHs are present in most samples, although petroleum-derived PAHs are dominant at Izmir Inner Bay, Dardanelles Strait and pyrolytic sources are prevalent in other sampling sites. A high contribution of perylene to the total penta PAHs was found greater than 70 per cent in Meric River Estuary, Dikili, Candarli and Gokova Bays. The spatial distributions of TALI and PAHs indicated that urban run-off and transport from the continental shelf is the major input pathway of anthropogenic and biogenic hydrocarbons from terrestrial sources in the near-shore area. PAH levels at all sites were below the effects range-low (ERL) and effects range-median (ERM) values except fluorene. The average and maximum fluorene concentrations exceeded ERL, but below ERM in the Izmir Inner Bay. The results indicated that the sediments should have potential biological impact.