Pollution and Health Risk Implications of Heavy Metals in the Surface Soil of Asafo Auto-Mechanic Workshop in Kumasi, Ghana

Heavy metals pollution and the resultant accumulation to toxic levels in soil may threaten human health through possible routes of exposures. This study seeks to assess the pollution and health risk implications of heavy metals in surface soil in auto-mechanic shop at Asafo in Kumasi, Ghana. Herein, a total number of 100 individual soil samples made into 20 composites were collected from automobile workshops at Asafo. Concentrations of Fe, Cu, Cr, Zn, Pb and Cd in soils were measured and used to estimate enrichment factor (EF), geo-accumulation index ( I geo ) and metal pollution index (PI), as well as carcinogenic and non-carcinogenic risks. Furthermore, Pearson’s correlation, principal component analysis (PCA) and cluster analysis were used to determine the relationship between the heavy metals and their possible sources. The extent of heavy metal pollution of soil in Asafo was in the decreasing order of Fe > Pb > Cr > Zn > Cu > Cd. Extreme contamination ( I geo < 5) was observed for Cr. Furthermore, the study revealed that the Cd may pose both carcinogenic and non-carcinogenic to human health. Correlation and PCA indicate that the main source of pollution could be related to the anthropogenic activities at automobile workshops. The present study therefore concludes that the artisanal activities at the Asafo automobile shops could contaminate the soil and eventually pose threat to humans; and provide a scientific basis for measures to protect human and environmental health in automobile workshops.