CONTAMINATION AND ECOLOGICAL RISK ASSESSMENT OF POTENTIALLY TOXIC ELEMENTS IN SOILS AROUND AROUND OLOMORE DUMPSITE IN ABEOKUTA, SOUTH WESTERN, NIGERIA

Abstract

Unsystematic deposition of wastes due to urbanization and industrilization has led to release of contaminants in soils and nearby water sources. This study investigated the effect of wastes on the concentrations of potentially toxic elemets (PTEs) in soils around a solid waste dumpsite, assessed their contamination status and ecological risk on the surounding area. Ten soil samples each collected from dumpsite, downslope, upslope and control site locations were analysed for Fe, Pb, Mn, Cd, Cu, Zn, As, Co, Cr and Ni concentrations were determined using Atomic Absorption Spectophotometer. The concentrations of PTEs in the soils were in order of Fe> Mn> Zn> Pb> Cu> Ni> Co> Cr> As > Cd. Concentrations of the Fe, Cu, Zn, Mn, Pb, Ni, Co and Cr in the studied soils were within the recommended values with the exception of Cd from dumpsite and downslope soils. Concentrations of PTEs are substantially higher in dumpsite than soils from other locations. The contamination factor and degree of contamination exhibit sparing to relative contamination of PTEs in soils. The geoaccumulation index values suggested non polluted to relatively polluted with PTEs in the soils while ecological risk indices showed sparing risk of the potential toxic elements in soils from the surrounding area. This study has shown the anthropogenic effects of wastes on the surrounding area.

Keywords

• anthropogenic
• accumulation
• wastes
• anthropogenic influence
• noxious