A Survey on Heavy Metal (Metalloids) Concentration in Selected Acidic and Volcanic Soils in Tanzania

A total of 12 soil samples from four different sites across the United Republic of Tanzania (URT) were collected and analysed for heavy metals (metalloids) (V, Cr, Ni, Cu, Zn, As, Cd, Hg and Pb) concentration. The technique used was Energy Dispersive X-Ray Fluorescence (EDXRF). Results show that the concentrations of 77.8% of the analysed heavy metals (V, Cr, Ni, Cu, Zn, Pb and Hg) were above the phytotoxicity limits while the rest, 22.3%, (As and Cd) were below the limits. The fact that 77.8% of the analysed heavy metals have concentrations above phytotoxicity limits raises a genuine concern on the favourability of these soils for agricultural purposes.