Heavy Metal Contamination Of Soils Around Municipal Solid Wastes Dump In Port Harcourt, Nigeria

Abstract

Levels of some heavy metals in soils around designated municipal solid waste dumpsite and a control site within Port Harcourt and its environs were determined. The soil samples were randomly collected and analyzed for As, Cd, Cu, Cr, Ni and Pb. Levels from the waste dumpsite were higher than those from the control site. Soils around the waste dump were also contaminated as a result of continuous dispersion of heavy metals from the waste dump by run-off water, wind and scavengers. The difference in the mean concentrations of metals between the main dump and outside the dump were not significant (P>0.05) in the wet season but were found to be significant (P<0.05) in the dry season. The concentrations of the metals in soils in both seasons ranged from 0.50μg/g to 20.5μg/g for As, 0.20μg/g to 13.0μg/g for Cd, 0.50μg/g to 100.0μg/g for Cr, 2.50μg/g to 910.0μg/g for Cu, 0.50μg/g to 34.0μg/g for Ni and 1.0μg/g to 127.5μg/g for Pb. The difference observed in the concentrations of Cd, Cu and Pb in both seasons are statistically not significant (p > 0.05 Pb) while the seasonal variations in the concentrations of As, Cr, and Ni show signification difference (P<0.05). Cd, Cr, and Cu showed positive correlation with distances across the waste dump (r = 0.9236, 0.9338, 0.3586 respectively). The mean concentrations of Cd and Cu in the soils from the waste dumpsite are sufficiently high to cause environmental concern as their concentrations exceeded tolerable limits.

KEY WORDS: Dumpsite, solid waste, soil, heavy metals

Global Journal of Environmental Sciences Vol.4(1) 2005: 1-4