Abstract

Mbalmayo is a medium city in Cameroon facing several problems including urban waste management. These wastes are sometimes incorporated into the urban soil due to a deficient collection system. The purpose of this study was to assess the concentrations of Trace Metals (TMEs) in soils intensively used for agriculture. Soil samples from three sites were analyzed for environmental physical chemistry and by Inductively Coupled Plasma Mass Spectrometry (ICP/MS). Some indices, including the enrichment factor (EF), the Geo-Accumulation Index (Igeo) and the Pollution Index (PI) were calculated to reflect the intensity of the contamination risk. The results for Cadmium (Cd), Copper (Cu), Iron (Fe), Manganese (Mn), Lead (Pb) and Zinc) Zn concentrations showed values of 0.10-0.45; 10.33-28.34; 1195-20020; 26.03-61.61; 15.60-48.00 and 40.12-206.36 mg/Kg respectively. They revealed highly variable levels of the defined trace metals. The presence of these hazardous elements in soils indicates a potential risk to the environment. The pollution index ranges from 0.13 to 0.31 and the enrichment factor is 0.11 to 8.58. This indicates a low to high enrichment of the soils in metallic trace elements. These results confirm a deterioration of soil quality.

Keywords:Trace metallic element; Contamination; Uncontrolled urbanization; Soil quality