Assessment of Heavy Metal Pollution from Granite Quarrying in Akure, Nigeria

Abstract

This study investigated the heavy metals pollution of granite quarrying activities in Akure, Ondo State, Nigeria. Three quarries and a control site were selected for this study. Plants and soil samples were collected at 0, 50, 100, 150 and 200 m away from the crushing points, while samples were collected away from roadside for control. Water samples were collected at just a point. Concentration of heavy metals in collected samples was determined using Buck Scientific Atomic Absorption Spectrophotometer model 210 VGP. The mean total heavy metal contents in C. odorata and P. purpurem collected within 0 to 200 m showed that Pb, Fe, Zn, Cr Co and Cd contents were above the WHO permissible limit while only Pb content (190.8, 299.20 and 208.80 ppm) and Fe (7559.50, 13386.50 and 19019.50 ppm for Dortmond, Ebenezer and Samchase quarries respectively) were above the permissible limit in soil samples. Elevated Pb, Fe, Cr, and Ni were recorded in water samples collected from quarry sites while values recorded for control sites falls within the permissible limit except for the lead concentration of 0.10 ppm as against the maximum concentration of 0.05 ppm set by WHO. Zn, Mn, Cd and and Cu were not detected in all water samples. Higher pH values were also recorded in soil and water samples from quarry sites. This study has shown that quarrying introduces toxic heavy metals into nearby environment.