Tovide Olukemi Omotunde, Olowu Rasaq. Adewale, Moronkola Bridget Adekemi Ayejuyo O Olusegun, Adeniyi A Adeleke
The speciation of metals in environmental samples is a serious factor in appraising the potential environmental impacts, before their disposal. The distribution and speciation pattern of toxic heavy metals in dumpsites soil samples collected randomly from three sites for a period of five weeks between the months of October and November, 2006 were subjected to stepwise sequential extraction method. The five step extraction procedure previously proposed by stone was used with modification to systematically study the speciation of cadmium and lead in dumpsite soil. The extracts were analyzed for heavy metal, using atomic absorption spectrophotometry (AAS). The concentrations of solubilized fraction profile for Cd and Pb in the solid samples were from 1.20 and 1.60, 3.00 and 7.20, 1.47 and 2.10 (μg/kg): from Ojota, Oke-Afa and Solous respectively. Conversely, the unsolubilized fractions of Cd and Pb in the soil samples showed a profile of 8.40 Pb and 2.70 μg/kg Cd for Ojota, 2.40 Pb and 1.90 μg/kg Cd for Solous while 13.60 μg/kg was obtained for Pb and Cd was not detected in Oke-Afa soil sample. The pH value ranged from 7.14 -7.68 with Ojota soil sample recording the highest value of 7.68 while the moisture content value of the soil samples ranged from 17.35-47.36% respectively.
