Indian Journal of Science and Technology

Abstract

Soil profile at 5 agricultural areas within and around Ifon, southwest, Nigeria and at the sides of a major road in the region were investigated to determine the contents of Pb, Cd and Zn, in order to ascertain their availability to plants, animals and humans. The procedure used involved sequential extractions technique. Generally metal contents decrease with depth. Their concentrations are Cd (0.68-1.93 mgkg^-1), Pb (4.27-6.21 mgkg^-1) and Zn (33.16-46.63 mgkg^-1) except for the roadside soils with ranges of 114.32-141.96 mgkg^-1 for Pb, 9.71-11.78 mgkg^-1 for Cd and 123.13-132.25 mgkg^-1 for Zn. Sequential extractions show that the mobility factors are low for Pb at all sites under study while those of Cd are high in Ifon soils. Values of mobility factor are only high for Zn in site C. This study shows that rural areas with link-roads to urban cities are prone to heavy metals bioaccumulation. It recommends heavy metals status-depended selective use of soils and provides a programme for monitoring such environment.
Keywords: Heavy metals, bioavailability, soil use, Ifon.