Abstract:
The disposal of waste to open dumpsites is the most common method of waste management and remains so in many places in Nigeria. Most dumpsites are located within the vicinity of living communities and wetland. The wastes contain toxic metals which are of great concern and poses serious dangers to the people in contact with the contaminated soil and plants. This research was undertaken to determine the level of some heavy metals pollution in soil collected from within and around three different waste dumpsites in Sapele town. Five heavy metals; Cadmium (Cd), Nickel (Ni), lead (Pb), Iron (Fe) and Zinc (Zn) were determined using Atomic Absorption Spectrophotometer (AAS). The concentration of heavy metal recorded in the soil samples from the study area ranges from 4.67 0.10 to 17.16 0.03 mg/kg for Cd, 5.33 0.05 to 10.02 0.03 mg/kg for Ni, 27.51 0.07 to 56.06 0.03 mg/kg for Pb, 866.11 0.06 to 1346.79 0.16 mg/kg for Fe and 87.86 0.09 to 163.05 0.02 mg/kg for Zn respectively. The concentration of cadmium and Iron recorded in the soil samples were above the maximum permissible limit reported by WHO (1996), FEPA (1991) and E.U (2002). The level of Zn recorded in the soils were above the maximum permissible limit set by WHO (1996), but were found below the safe limit reported by FEPA (1991) and E.U (2002). The concentration recorded for lead and nickel were below these safe limits. The concentration of heavy metals in the soil samples were in the order; Fe> Zn> Pb>Cd>Ni. The contamination factor (Cf), Geo accumulation index (Igeo), Pollution load index (PLI) and Potential ecological risk (Eri and Ri) indices were calculated, and the results indicate that the sites were heavily contaminated with Cd and moderately contaminated with Fe and Zn. The results also revealed the control site to be moderately contaminated with Fe which could be as a result of natural occurrences. |
