Assessment of trace metals contamination of soils around some automobile mechanic workshops in Oyo South-Western Nigeria

Abstract

This study was carried out to determine the level of soil contamination by metals around some automobile mechanic workshops in Oyo town in order to assess their possible adverse health implications on man and his environment. Concentrations of metals above certain levels have been shown to impair man’s health. Automobile mechanic workshops are sources of metals discharge into the environment and most of these workshops in Oyo are sited within residential areas. 12 samples of top soils were therefore collected from some automobile mechanic workshops within Oyo town and analyzed for Lead (Pb), Manganese (Mn), Zinc (Zn), Chromium (Cr), Vanadium (V), Copper (Cu), Strontium (Sr), Cobalt (Co), Nickel (Ni) and Cadmium (Cd) using the Inductively Coupled Plasma Mass Spectrometry (ICP-MS) technique. The indices of contamination including Geo-accumulation index, Contamination Factor, and Degree of Contamination were used to determine the pollution status of the soils. Pb and Zn were the main metals of pollutant status with Pb having very high Contamination Factor, and the soils in general showing very high degree of contamination. This high level of Pb and Zn in the environment is significant with possible health risk to man and his environment.

Keywords: Automobile mechanic workshops, Contamination Factor, Degree of Contamination, Geo-accumulation Index, Oyo town, Soils