A comprehensive environmental analysis of heavy metal contamination, ecological risks and health impacts in Ilokun area, Ado-Ekiti, Nigeria

Abstract

Heavy metal contamination in ecosystems is a global environmental and health concern. This study assessed the ecological and health risks associated with heavy metal pollution in farmland, dumpsite, stream land, and plant roots in Ilokun, Ekiti State, Southwest Nigeria. Samples were collected from different locations and analyzed for levels of heavy metal concentrations of cadmium (Cd), lead (Pb), manganese (Mn), chromium (Cr), copper (Cu), nickel (Ni), and zinc (Zn) using atomic absorption spectrophotometer. Various pollution indices such as enrichment factor, contamination factor, and geo-accumulation index were employed. Ecological risk methods were used to investigate the pollution status, heavy metal sources, and health risks associated with urban soil. The results showed that the concentrations of these metals exceeded permissible levels at most sampling sites, indicating significant contamination of the samples. Manganese, Cu, Pb, and Zn were the dominant metals in our study, and overall, the following trend: Mn > Zn > Cr > Ni > Cu > Pb > Cd. The contamination factor revealed that Cu, Zn showed moderate contamination, and Pb, Ni, and Mn showed high soil contamination. The ecological risk assessment demonstrated that Pb and Ni were associated with high risks due to anthropogenic influences related to coal combustion, vehicle exhausts, and automobile brakes. The findings indicate severe heavy metal media enrichment in the study area, which may lead to adverse ecological effects and health risks.