Ecological Studies of Heavy Metals in E-Waste Dumpsites from Two Local Government Areas of Ogun State, Southwestern Nigeria

Abstract

The study analyzed soil samples from e-waste dumps in two local government areas of Ogun State, Nigeria, to determine the concentrations of nine heavy metals. Samples were analyzed using spectrophotometric techniques. The results were used to assess ecological health risks and conduct correlation analysis. The study found that the dumpsites had high residue concentrations of Cd, Zn, Pb, and Fe, exceeding WHO acceptable limits, also concentration of Zn and Fe at the control sites exceeds WHO limits. At the dumpsite in Ijebu-Ode, Cd had an extremely high enrichment factor of 126.67 and an Igeo of 6.400, while the dumpsites at Ijebu North, Pb had the highest enrichment factor values of 14.063 and an Igeo of 3.229 respectively which suggested severe enrichment. Therefore, the dumpsites have a high pollutant of lead. The risk index for both Ijebu North and Ijebu-Ode LGA dumpsites were 396.983 and 3916.273 respectively and thereby indicating significant risk of toxic pollution and soil contamination respectively. The high-risk index value at the Ijebu-Ode dumpsites was caused by the excessive Cd contamination in Ita-Osu. Common anthropogenic sources of the contaminants were indicated by the correlation analysis.