Potentially Toxic Elements (PTE) Pollution in Apomu Suburban Area on southwestern Nigeria

Abstract

Potentially Toxic Elements (PTE) contaminated soils within urban areas have received global attention. However, little attention is being given to soils of suburban areas, which are also vulnerable to PTE contamination from both natural and unnatural sources. This study was conducted to determine soil quality and PTE pollution sources in soils of Apomu, Southwestern Nigeria. The concentration of PTEs was determined by subjecting soils to elemental analysis using Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). Pollution indices and health risks were calculated. The results showed the following range of metal concentrations in ppm except for Al (%) in increasing order; Mo (0.58-12.29), Cu (16.65-687.47), Pb (28.64-368.75), Zn (0-9257.30), Ni (7.60-86.20), Mn (403-1756), Cr (26.40-107), Cd (0.20-11.34), and Fe (1.23-4.29). Geoaccumulation Index (Igeo) showed that Zn, Pb, Ni and Cu and moderately contaminated with Cd. The Enrichment Factor (EF) revealed minimal to very high enrichment of Cu and Zn; minimal to significant enrichment of Pb and As and a minimal to moderate enrichment of Ni and Co. The geochemical evaluation revealed that soils were heavily contaminated with PTEs which were sourced from geogenic and anthropogenic activities. Approximately 70% of sampling areas exhib[1]ited high potential ecological concerns. The hazard index (HI) values for children and adults were less than one (HI < 1), indicating that there was no major danger of poisoning. Carcinogenic risks for Cd, Ni, and Pb were calculated and found to be within tolerable limits, but children are more susceptible to cancer and non-cancer risks than adults.