Accumulation of Lead, Cadmium and Iron in Topsoil of Ori-Ile Battery Waste Dumpsite and Surrounding Gradient Point Areas at Olodo, Ibadan, Nigeria

摘要

The disposal of waste is proving to be a major public health issue and a vital factor affecting the quality of the environment especially in the developing countries. Battery waste consists of toxic heavy metals and its incongruous disposal on the Ori-Ile battery waste dumpsite at Olodo, Ibadan has elicited public health concerns. This study was designed to determine the concentration of lead (Pb), cadmium (Cd) and iron (Fe) within the topsoil of Ori-Ile battery waste dumpsite and surrounding gradient point areas at Olodo, Ibadan, Nigeria. An auto-battery Waste Dumpsite (WD), Ori-Ile, Olodo was purposively selected for the study. One hundred and thirty six (136) soil samples were collected every two months (March 2008 to July 2009) from the waste dumpsite and along the along North, South, East and West (N, S, E, W) directions at 5 m intervals from the edge of the wastedump site. Control soil samples were collected from Moor Plantation (MP), Ibadan. All soil samples collected were analyzed for Pb, Cd, and Fe. Mean concentrations of Pb, Cd and Fe concentration (mg/kg) in topsoil from the waste dumpsite was Pb: 4273.8±1436.7, Cd: 258.4±123.1, Fe: 7910.0±791.5 while that from North was Pb: 4693.8±1107.9, Cd: 274.3±94.8, Fe: 8346.7±740.0; South was Pb: 4353.3±867.0, Cd: 255.2±71.4, Fe: 8189.6± 603.5; East was Pb: 4351.3±832.9, Cd: 248.2±65.6, Fe: 8130.0±639.5; West was Pb: 4698.3±1020.8, Cd: 278.4±86.9, Fe: 7851.3±676.8 respectively. These were significantly higher than values obtained from the reference soil (157.0±39.8, 2.2±1.2, 976.3±353.9 mg/kg respectively) and National Environmental Standard Regulation Agency (NESREA) limits (164mgPb/kg and 50mgCd/kg). Also, soil contamination factor values obtained were greater than 6 and this indicated severe contamination. Overall, these results have shown that the levels of Pb, Cd and Fe in all sampled topsoil were several folds above the limits set by NESREA. High accumulation of heavy metals was found in the topsoil of Ori-Ile battery waste dumpsite, Olodo, Ibadan and its surroundings and this could lead to further contamination of surface water, ground water and living organisms within this polluted sites. The health of all living biota within the area could also be negatively impacted.