Preliminary assessment of heavy metals levels of soils of an oil field in the Niger Delta, Nigeria

This communication presents the results of preliminary investigation of the characteristic levels of heavy metals in surface soils of an oilfield in the Niger Delta. The results indicate higher concentration of the following metals: Cd, Pb, Cu; Ni, Zn, Cr, Mn and Hg in soils around the gas plant than the pipeline areas. There is a significant temporal and spatial variation in the concentrations of the heavy metals. Samples collected during the wet season showed lower concentrations of heavy metals. The distribution pattern of heavy metals follows the following order Fe> Mn> Zn> V> Cr> Pb> Cu> Ni> Cd> Hg> As. The soils around the oilfield could be considered unpolluted since the concentrations of the metals fit into background levels and concentrations found in natural and agricultural soils. Since metal build up is a gradual process, farmland, fishing ponds and water bodies closer to these facilities will be at risk of heavy metal pollution over time.