Examining the Soils Adjacent to the Historical Pitch Lake for Levels of Polycyclic Aromatic Hydrocarbons (Pahs) and Naturally Occurring Pah-Degrading Bacteria

Polycyclic Aromatic Hydrocarbons (PAHs) exhibit carcinogenic and/or mutagenic properties and these are listed by the United States Environmental Protection Agency (US EPA) and European Commission (EC) as priority pollutants (Amellal et al., 2001). The European standards for PAHs in soils, sediments, and groundwater has been well documented and evaluated in recent years (Lijzen et al., 2001) and will be used as the baseline for purposes of this research. Utilizing the revised clean up standards for an average soil for the Netherlands (10% organic matter and 25% clay) should range between 140 mg(PAH)/Kg dw, if it is greater than 40 mg(PAH)/Kg dw, then remediation should be undertaken(Harmsen, 2004). Generally in the natural terrestrial environment from biological processes, soils are estimated to have levels of 1–100 μg/Kg PAHs (Wilcke, 2000), whereas concentrations of PAHs in highly polluted soils can range anywhere from 10 mg/Kg to 10 g/Kg dry weight (Stieber et al., 1994).