Delineation of heavy metals in soils from auto-mechanic workshops within Okitipupa, Ondo State, Nigeria

Abstract

Auto Mechanic Workshops in the study area generate waste containing hazardous, soil samples were collected from selected automobile workshops (four) in the study area at the depths of 0-15cm, 30-45cm, 45-60cm, 60-75cm and 75-100cm. A total of twenty- four (24) soil samples were collected in four different locations in the ancient town of Okitipupa. Six control samples were also collected in a farm land about 3km away from Auto Mechanic Activities.  The soils were analysed for heavy metals levels. Ten heavy metals (Cd, Zn, Cu, Cr, Pb, Fe, Mn, Co, Ni and Mg) were analysed using AAS techniques. The heavy metal concentration for the ten metals determined in soil was in the order; Fe > Mg > Zn >Mn> Cu >Pb> Ni > Cr > Cd > Co. Heavy metals concentrations (mg/Kg) Ranging from 0.01±0.00 to 112.00±0.00 in all the sites. Site C is about ten years older than others recorded the highest concentrations of heavy metals in all the sites. Comparing the results of the study area with the control shows that the study area is moderately contaminated; the values obtained were below the DPR permissible limit for soil. It is therefore recommended that a separate portion of land be set apart for automobile workshops in Okitipupa.

Keywords: Heavy metal, soil, pollution, automobile, profile, contamination plume.