Evaluation of trace metal content in soils subjected to inputs of solid urban wastes

Abstract

Large amounts of solid urban waste (SUW), sometimes containing trace metal (TM), are used to fertilize agricultural soils. The aim of this study was to assess concentrations of TM in peri-urban agricultural soils exposed to SUW inputs around Bobo-Dioulasso. Composite samples of fourteen soil profiles (0-20 cm, 20-40 cm and 40-60 cm) were collected in the classified Dindéréso forest in the outskirts of Bobo-Dioulasso. Inductively coupled plasma mass spectrometry (ICP/MS) was used to analyze TM concentrations in the samples. Concentrations of Cd, Cr, Cu, Ni, Pb and Zn varied broadly according to the sampling sites and soil horizons. The maximum concentrations of the analyzed elements in all sites were lower than the limit concentrations. Regardless soil horizons, the pollution index were less than 1, suggesting that the sampled soils were not subject to multiple contaminations of TM.