Polycyclic aromatic hydrocarbons in surface water and soil in the vicinity of fuel-oil spillage from a tank farm distribution facility, Esuk Utan, Calabar Municipality, Nigeria

The concentrations of total polycyclic aromatic hydrocarbons (∑PAHs) and 16 individual PAH compounds in 6 surface water and 44 soil samples collected from the vicinity of spilled fuel from a pipeline which carries fuel from a jetty to the tank farm were analyzed. The ∑PAHs concentrations in surface water ranged from 0.37 to 99.30 mg/l with a mean concentration of 57.83 mg/l. The ∑PAHs concentrations in water are of several orders of magnitude higher than in unpolluted water and some national and international standards including in some surface water in other parts of the world. This suggests that the surface water of the area were heavily polluted by anthropogenic PAHs possibly from the spills. The total PAH concentrations in soil ranged from 16.06 to 25,547.75 μg/kg with a mean concentration of 2,906.36 μg/kg. ∑PAH concentrations of the seven carcinogenic PAH compounds in soil varied between 0.02 and 97,954 μg/kg. In terms of composition of patterns in surface water and soil, the PAHs were dominated by four and three rings. The distribution pattern showed marked predominance by low molecular weight compounds. In comparison with ∑PAHs concentrations in other part of the world, the total PAH concentrations of this area were higher than those reported for some urban soils in some regions of the world. The ratios of Phe/Ant, Flu/Pyr, Flu/(Flu + Pyr), and BaA/(BaA + Chyr) in both water and soil indicated various sources of PAH in the area. These sources include fuel spills, burning of motor tyres and vegetation, vehicle repairs and washing, motor exhaust and fire wood burning from cooking.