Evaluation of Polycyclic Aromatic Hydrocarbon (PAH) concentrations in Crabs and Shrimps from Crude Oil Polluted Waters of Ogoniland in Rivers State, Nigeria.

Abstract

This study was carried out to evaluate PAHs concentration in crabs (Callinectes pali)and shrimps (Penaeus notialis) collected from Kaa, B-Dere and Bodo City in Ogoniland, Rivers State, Nigeria. These samples were measured by gas chromatography with flame ionization detector (GC/FID). The Average concentrations of these PAHs ranged from below detection limit of 0.0001 to 90.7 ± 1.00 µg/kg wet wt. in Callinectes paliand from 0.0001 to 77.5 ± 1.65 µg/kg wet wt. in Penaeus notialis. The highest average concentration of90.7 ± 1.00 µg/kg wet wt. was recorded for Benzo(b)fluoranthene from Bodo City. Between the two species, Callinectes pali accumulated significantly higher concentrations (P < 0.05) of total PAHs at all the sites except at Kaa. High molecular weight PAHs (HMW-PAHs) were generally predominant compared to low molecular weight PAHs (LMW-PAHs). The LMW- PAH/HMW-PAH ratios were < 1 for both species, indicating anthropogenic, mainly pyrogenic, origin of PAHs in Kaa, B-Dere and Bodo City of OgoniLand. Concentration of benzo(a)pyrene in Callinectes pali collected from B-Dere and Bodo City analyzed exceeded the EU recommended limit of 2 µg/kg wet wt., while that in Penaeus notialis collected from the three sites were below EU recommended limit of 2 µg/kg wet wt. in food. Thus, PAHs residues in the examined Callinectes pali were high and would constitute threat to human health than those in Penaeus notialis. The public health concerns of PAHs are cancer, mutations and birth defects as discussed.