Assessment of Polycyclic Aromatic Hydrocarbons (PAHs) Levels in Two Commercially Important Fish Species from crude oil polluted Waters of Ogoniland and Their Carcinogenic Health Risks

Abstract

This work was carried out to assess the levels of Polycyclic Aromatic Hydrocarbon (PAHs) in selected fish species. Concentrations of PAHs were determined in edible tissues of selected important seafood’s (Tilapia queneesis and Liza falcipinis) collected from three coastal water of OgoniLand, namely, Kaa, B-Dere and Bodo City. PAHs levels in the 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 120 ± 1.18 µg/kg wet wt. in Tilapia queneesis and from 0.0001 to 78.6 ± 1.28 µg/kg wet wt. in Liza falcipinis. The highest average concentration of 120±1.18 µg/kg wet wt. was recorded for Benzo[b] Fluoranthene from Bodo City. Total PAH concentrations in Tilapia queneesis from Kaa were significantly lower (P < 0.05) than total PAHs concentrations in fish from B-Dere. Between the two fish species, Tilapia queneesis accumulated significantly higher concentrations (P < 0.05) of total PAHs.  High molecular weight PAHs (HMW-PAHs) were generally predominant compared to low molecular weight PAHs (LMW-PAHs). The LMW- PAH/HMW-PAH ratio was < 1 for species, indicating anthropogenic, and origin of PAHs in the OgoniLand coastal environment. With the exception of Tilapia queneesis from Kaa, Bodo City and Liza falcipinis from Kaa, benzo[a]pyrene concentrations in the fish samples analyzed exceeded the EU recommended limit of 2 µg/kg wet wt. for fish. The estimated carcinogenic potency equivalent concentrations exceeded the screening value for both species from all the study areas, indicating significant carcinogenic health risks associated with the consumption of these fishes.

Key words: carcinogenic, Liza falcipinis, OgoniLand, PAHs, Tilapia queneesis.