ASSESSMENT OF SOME HEAVY METALS CONCENTRATIONS IN SOIL AND GROUNDWATER AROUND REFUSE DUMPSITE IN IBADAN METROPOLIS, NIGERIA

Abstract

This study reports the determination of some heavy metals’ concentration in soil and groundwater around refuse dumpsites in five locations in Ibadan Metropolis, Nigeria. Five samples were collected from each soil and groundwater locations and analysed for heavy metals(Cd, Co, Pb, Cr, Zn, Mn and Ni)using Atomic Absorption Spectrophotometry. The soil samples were obtained in triplicates at 25 cm depth intervals whereas the water samples were obtained from hand dug wells less than 10 m deep. The range of the values of heavy metal concentrations obtained in water is Co (0.01-0.04), Pb (0.01-0.02), Cr (0.02-0.05), Zn (0.40-0.70), Mn (0.02-0.05) and Ni (0.02-0.05), but Cadmium was not detected. The concentrations of Pb and Ni in ground water obtained from Arapaja, Aleshinloye and Alafara were higher than the World Health Organization (WHO) and Standard Organisation of Nigeria (SON) limits. The results obtained showed that the concentrations of Cd, Co, Pb, Ni and Cr in soil exceeded the WHO and SON permissible limits. However, Zn and Mn were below the limit.