Polycyclic aromatic hydrocarbons (PAHs) in surficial sediments from selected rivers in the western Niger Delta of Nigeria: Spatial distribution, sources, and ecological and human health risks.

This study assessed the concentrations, sources, and risks of polycyclic aromatic hydrocarbons (PAHs) in sediments from the Rivers Niger, Ase and Forcados in the western Niger Delta. The concentrations of PAHs (in μg kg dry weight), as determined by gas chromatography-mass spectrometry, in sediments from these rivers varied from 2400 to 19,000, 2930 to 16,100, and from 1620 to 19,800 for the Niger, Ase and Forcados Rivers respectively. High molecular weight (HMW) PAHs were the most prevalent compounds present in these sediments. An assessment of the possible ecological and human health risks suggested high risks for both organisms and humans. The PAH source analysis suggested that sediments from these river systems were contaminated with PAHs arising from burning of biomass, gasoline/diesel emissions, burning of natural gas, and oil spillages.