CONCENTRATION OF HEAVY METALS IN THE SOIL AND PLANTS AROUND WASTE DUMPSITES IN ENUGU METROPOLIS, NIGERIA

Abstract

Aims: The purpose of this project is to find the concentration of heavy metals (Cu, Zn, Pb, As, Cr, Ni, Cd, Fe and Mn) in the top soil and the plant around the waste dumpsite from Enugu municipal solid waste disposal sites. Methodology and results: This was done through collection of soil samples from four designated public municipal solid waste dump sites (Ngwo Umueze, Presidential, New-market and Emene) in Enugu metropolis. The soil samples were collected at 10 metres intervals away from the centre location point of each dump site at constant depth (0 - 15 cm were mixed together and sample picked from it). The samples collection design are as follows: centre (0m) of the dump sites, 10 metres, 20 metres, 30 metres and the control sample which measured 65 metres away from the centre of dumpsites at the same depth. Plant samples were taken just at the centre (0m) and control measures which is at 65 meters distance away from each dump sites. The Goat grasses harvested were taken to the lab to check and analyse its heavy metals intake from the soil. These samples were analysed using atomic absorption spectrophotometer (AA320N) model. On the average, high concentrations of Zn, Fe, Mn, Cu, and Pb were found in the soil samples collected at the centre of the dump sites as 141.70, 121.5, 75.53, 70.33 and 64.53mg/kg respectively. The lower concentrations were obtained in the soil samples taken at the control site which 65 metres distance away from the centre of the four dump sites as 12.00, 81.55, 8.70, 9.56 and 6.51mg/kg for Zn, Fe, Mn, Cu, and Pb respectively. In the plant sample, concentration of Fe (98.00 mg/kg) was found to be the highest in the root at New market dumpsites, while Nil concentration of as (Nil mg/kg) was the least value at Emene from the control distance. Conclusion, significance and impact study: SPSS statistical package was used to find out the significant differences between the treatments mean (heavy metals). The result shows that the heavy metals analyses were within the acceptable or permissible limit by WHO/FAO.