Assessment of Heavy Metal Concentrations in Crude Oil Contaminated Soils in Rumuekpe Community, Emohua LGA, Rivers State, Nigeria

Abstract

The study assessed the heavy metal concentrations in crude oil-contaminated soils of Rumuekpe Community, Emohua LGA, Rivers State, Nigeria. Soil samples were collected using the stratified random sampling and composite sampling techniques from the crude oil-contaminated sites within of the study areas for two months. Soil samples were air-dried, homogenised, and sieved before digestion. Thereafter, the soil samples were subjected to Atomic Absorption Spectrophotometry (AAS) to determine the concentrations of Cd, Ni, Pb, Zn, Cr and Fe in the contaminated soil and the control soil. Descriptive statistics in form of tables, charts, mean and standard deviation were employed for data presentation for the study. Results showed that the mean concentrations of Cd (2.176 mg/kg), Ni (6.11 mg/kg), Pb (4.29 mg/kg), Zn (10.12 mg/kg and Cr (5.985 mg/kg) were all higher than the control baseline heavy metals contents of 0.09 mg/kg, 0.0003 mg/kg, 0.0002 mg/kg, 1.37 mg/kg and 0.024 mg/kg respectively which is suggesting that the concentration of heavy metals due to the response of the soils to crude oil pollution increased considerably. The study concluded that the concentrations of heavy metals including cadmium, nickel, lead, zinc and chromium were high in crude oil contaminated soil and the soil quality in the crude oil contaminated soil have been degraded for human use. It is thus recommended among others that oil companies, especially those ones whose activities are carried out on-shore and in shallow waters should adopt best practices of the industry to avoid incessant oil spill so as not to pollute farmlands and other soils of economic and ecological value.