Assessment of Concentrations of Heavy Metals in Soils around ESPRO Asphalt Production and Quarry Site, Wasinmi, Osun State Southwest Nigeria

Abstract

This work examined the concentration of heavy metals in soil samples around ESPRO Asphalt Production and Quarry Site located in Wasinmi, Irewole Local Government Area, Osun State. A total of nine (9) soil samples were collected from three points with distances of 0, 1 and 2 km from the quarry site. Atomic Absorption Spectroscopy (AAS) was used to determine the concentrations of heavy metals in the soil samples. The results revealed that the mean values metal contents in the soil samples analyzed were in the order Fe>Zn>Cu>Cr>Mn>Pb>Cd. The concentration of the heavy metals in the soil samples were found to decrease as the soil depths increased from 0-25 cm and also as the spatial distances of the sampled locations increased from the quarry plant. The study also showed that low concentrations of Lead (Pb) had a mean concentration value of 0.87 ppm and Cadmium (Cd) with a mean concentration value of 0.29 ppm. It was also observed that Iron (Fe) had the highest mean concentration value of 148.8 ppm. The study concluded that quarrying activities raised the soil heavy metal contents up to the range of about 2 km away from the quarry site. This can be attributed to the number of years of mining and excavation activities in the study area and accumulation of the heavy metal concentrations over time and this could be dangerous to the site environments, especially for farming and groundwater exploration activities in the area.