Evaluation of the Concentration of Selected Heavy Metals and the Effects on Soil Enzymatic Activities in an Abandoned Cement Factory Nigercem Nkalagu and Its Environs

Abstract

This study investigated the concentrations of heavy metals, the activities of some selected enzymes and the pH of the soil surface (1-10 cm) and depth (11-20 cm) within the vicinity of an abandoned cement factory Nigercem Nkalagu, and further away 1km from the factory centre. The results indicate that the pH and heavy metals gradually decreased with increase in distance from the cement factory centre with the exception of Fe, Zn and Pb which was the reverse. The concentrations were also higher in the depths. The enzymatic activities increased away from cement factory centre and decreased with depth. There was a significant difference (p ≤0.05) between most of the sampling points and the control (1 km) for all the parameters studied, except Cd and Cr. The enzymatic activities correlated positively with Fe, Zn and Pb and negatively with the other parameters. The inverse correlation between most of these heavy metals, the pH, and the activities of the soil enzymes are indicative that pollution caused by cement production still exhibit a significant effect on the enzymatic activities and this may invariably affect the quality of the soil of this area.