The Effects of pH On the Levels of Some Heavy Metals in Soil Samples of Five Dumpsites in Abeokuta and its Environs

The study shows the effect of pH levels of some heavy metals in soil samples collected from five dumpsites at Obada oko, Kobape, Idi-Aba, Osiele and Ijeun Titun, all within Abeokuta and its environs. Zinc, Cadmium and Lead in the soil samples of these locations were determined by digestion, then analysed using Atomic Absorption Spectrophotometer and the pH also analysed using calibrated digital pH meter. The data were subjected to statistical analysis using SPSS Version 20.0. The pH of the soil samples were inadequately and fairly acidic in nature with Zn higher concentrations observed in all the five dumpsites. However, the highest concentration of 107.200.8 g/g was recorded in Zn at the pH of 6.45 but Cd had the lowest concentration of 3.320.0 g/g, with Zn concentration of 75.750.2 g/g at pH 6.10 respectively. Conclusively therefore, soil samples from dumpsites investigated could not be recommended for crop production due to the levels of Zn and Pb present which is high enough to cause toxicity of growing plants and grazing animals. Vegetables growing or grown on these soils could not be suitable for human consumption due to the likelihood of bioaccumulation of these toxic heavy metals.