Polychlorinated biphenyls and organochlorine pesticides in Tiber River and Estuary: Occurrence, distribution and ecological risk

The polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) pollution in the Tiber River and its environmental impact on the Tyrrhenian Sea (Central Mediterranean Sea) were estimated. 32 PCBs and 17 OCPs (aldrin, α-BHC, β-BHC, δ-BHC, lindane, p,p'-DDD, p,p'-DDE, p,p'-DDT, dieldrin, endosulfan I, endosulfan II, endosulfan sulfate, endrin, endrin aldehyde, heptachlor, heptachlor epoxide, methoxychlor) were determined in the water dissolved phase (DP), suspended particulate matter (SPM) and sediment samples. Total concentrations of PCBs ranged from 0.54 to 74.75ngL-1 in water (sum of DP and SPM) and from 3.73 to 79.30ngg-1 dry weigh in sediment samples; while the concentrations of total OCPs collected in water (sum of DP and SPM) ranged from 0.07 to 7.04ngL-1 and from 0.66 to 10.02ngg-1 dry weigh in sediment samples. Contaminant discharges into the sea were calculated in about 227.08kgyear-1 for PCBs and 24.91kgyear-1 for OCPs, showing that this river should account as one of the main contribution sources of PCBs and OCPs to the Tyrrhenian Sea. The ∑TEQPCB from the sediment samples ranged from 0.0006 to 0.37ngg-1 with an average level of 0.13ngg-1. Based on Sediments Quality Guidelines, biological adverse effects on aquatic ecosystem were rare to occasional for PCB and OCP levels in Tiber water system