Levels of Polycyclic Aromatic Hydrocarbons (PAHs) and Associated Health Risk in Tilapia zilli from Qua Iboe River Estuary, Niger Delta, Nigeria

Abstract

Intensive oil activities within the study area have elevated the level of toxic substances in both aquatic and terrestrial environments of the host communities. Levels of polycyclic aromatic hydrocarbons in Tilapia zilli from Qua Iboe River estuary (QIRE) Nigeria and the carcinogenic health risk induced by its consumption were studied. Fish samples were collected from five stations and a Control during wet and dry seasons and analyzed for PAHs using gas chromatography with flame ionization detector. Carcinogenic health risk assessment using recommended models by USEPA was done. Concentrations of total PAHs ranged from 1.527E-03 to 5.986E-02 mg/kg, high molecular weight PAHs recorded a range of 1.239E-03 to 1.424E-01 mg/kg while low molecular weight PAHs ranged from 2.814E-04 to 3.166E-03 mg/kg. Concentrations of C-PAHs at the study area were higher than at the Control site. Levels of B(a)P in Tilapia zilli for both seasons were lower than the EU limit however, the potency equivalent concentrations due to exposure to C-PAHs via its at all locations in both seasons were above the screening value. Thus, consumption of Tilapia zilli from the area studied may result in carcinogenic health effect. The study also identified presence of anthropogenic inputs of PAHs and pyrogenic PAHs originated from gas flaring in the area. Regulatory legislation on environment should be instituted to forestall sub lethal effect on aquatic flora, fauna and human. Keyword: Health Risk Assessment; Nigeria; Polycyclic Aromatic Hydrocarbon; Qua Iboe River Estuary and Tilapia zilli.