Historical Trends of Polycyclic Aromatic Hydrocarbons (PAHs) in the Sediments of Toulon Bay (South of France)

The levels of 16 USEPA priority PAHs in surface sediments and four dated sediment cores from Toulon Bay were determined and characterized by strong implantation. The total PAH levels in the superficial sediments ranged from 0.30 to 34.11 mg.kg -1 dry weight in the 0-5 layer and from 0.34 to 54.68 mg.kg -1 dry weight in the 5-10 layer. The qualitative assessment of sediment samples revealed relatively high PAH levels compared with French reference values. The results indicated that the PAHs in Toulon Bay are of pyrolytic origin. Estimating the rate of sedimentation based on pronounced events, such as explosive growth in the use of petroleum products, major developments, and periods of conflict, can be used to follow the history of pollution based on its composition over a period of approximately 130 to 180 years, depending on the length of the cores.