Crude Oil Contaminated River Fishes arising from the Activities of Illegal Petroleum Refining in Oshika and Egbalor Communities in the Niger Delta Region of Nigeria

Abstract

This study evaluated catfish from the impact of crude oil as contaminants on catfish caught from the surrounding streams of two selected sites of illegal petroleum refineries which have been abandoned as a result of its destruction by the government Task Force against illegal refineries. Laboratory analysis was carried out on the samples from the two sites at Oshika and Egbalor communities and a control, all in Rivers State, Nigeria. Tests for Heavy metals (Cd, Ni, As, Zn, Cu, Co, Cr, Pb), Polycyclic Aromatic Hydrocarbon (PAH), Benzene, Toluene, Ethyl benzene and Xylene (BTEX) and Total Hydrocarbon Content (THC) were carried out with Atomic Absorption Spectrophotometer (AAS) and Gas Chromatograph-Flame Ionization Detector (GC-FID). Duncan’s New Multiple Range Test Statistical method was used in the analysis. This study showed that the concentrations of heavy metal pollutants in Fish followed distribution patterns of Cu>Pb>As>Co>Ni>Zn>Cr>Cd in Oshika site while that of Egbalor site is Zn> Cu> As> Ni> Cr> Co> Cd> Pb Which are all higher than WHO recommended permissible limits and control except Zn. This makes the fish contaminated from the illegal refinery activities. The result showed high concentrations of Polycyclic Aromatic Hydrocarbons (PAH)s in the sampled fish which are higher than the WHO recommended permissible limits and USEPA regulatory standard values for PAHs with a corresponding 30.09% and 11.64% of carcinogenic PAHs for Oshika and Egbalor sites respectively, thereby making the fish toxic. Recommendations were made for possible mitigation for illegal refineries.