The levels of accumulation of heavy metals (Cr, Cu, Pb, Ni and Zn) in Olusosun dump soil (in Lagos State, Nigeria) due to municipal solid waste were investigated. Soil samples from the abandoned dump soil and also from the new section currently in use at the time of this study were analysed and the results compared with that of a farmland soil used as control. Soil pH and organic matter were also determined. The concentration of heavy metals in the soil was determined using Atomic Absorption Spectrophotometer. The result of analysis of soil samples from the abandoned, the new dump sites and the control site respectively, indicated that soil samples contained zinc (448.95 + 3.97, 67.31 + 8.87, 27.75 + 0.49mg/kg), lead (155.07 + 31.11, 47.15 + 0.75, 13.26 + 0.35mg/kg), copper (64.56 + 4.96, 45.79 + 0.81, 10.39 + 0.27mg/kg), chromium (18.44 + 1.38, 25.55 + 2.51, 8.11 + 0.28mg/kg), nickel (5.99 + 0.51, 1.44 + 0.09, 4.74 + 0.11mg/kg), pH (7.65 + 0.02, 7.22 + 0.07, 6.43 + 0.11) and organic matter (22.83 + 1.57, 14.37 + 1.16, 4.20 + 0.14%) respectively, and were significantly different at p < 0.05. The distribution pattern of heavy metals in the soil profiles were in the following order Zn > Pb > Cu > Cr > Ni. The concentrations of metal in the abandoned dump soil were higher than that of the new dump soil, while the metal concentrations in both sites were in turn higher than the level in the normal farmland. This shows that the municipal wastes are contributing significantly to the metal concentrations in dump soil samples.

Keywords: dump-soil, heavy metals, farmland, concentrations