Characterization and analysis of polycyclic aromatic hydrocarbons in the sediments of the Dora Region

Abstract

Water and sediment contamination is a growing ecological issue. Natural toxins and organic pollutants are exchanged to the water environmental compartment by various human activities, such as shipping, oil leaks, beach front oil businesses, manures and agriculture, and fossil fuel ignition. These pollutants can then be transported to the sediments. The most common organic pollutants present in the marine sediments are Polycyclic Aromatic Hydrocarbons (PAHs), Polychlorinated Biphenyls (PCBs), and Organochlorine Pesticides (OCPs). In Lebanon, the characterization of these organic pollutants is recent and was conducted in just four studies so far. The aim of this project is to determine and analyze the concentration of Polycyclic Aromatic Hydrocarbons (PAHs) in the marine sediments of the Dora region facing the previously known dumping site. To achieve this purpose, a sequence of experimental stages was performed. These are: pre-sampling, sediments sampling, lyophilization or freeze drying, pressurized liquid extraction (PLE) and concentration, and gas chromatography. The total PAHs concentrations ranged from 14.523 to 250.629 μg/kg dry weight. PAHs were mainly of pyrogenic origin, with some samples having a petrogenic source of contamination. Pyrogenic sources are mostly attributed to inadequate fuel ignition, while petrogenic sources can be related to petroleum associated activities, for example, oil leaks.