GEOCHEMICAL ASSESSMENT OF TRACE METALS IN SOIL, STREAM WATER AND SELECTED FOOD CROPS AT KIBI GOLDFIELDS ENVIRONMENT, GHANA

Abstract

This study assesses environmental receptors impacted by alluvial gold mining at Kibi Goldfields Limited in the Eastern region of Ghana to establish trace metals contamination risk. Specific objectives are to determine concentrations of (1) As, Cr, Ni and Pb in soils, drainage and food crops, using X-ray fluorescence, (2) Cl- in drainage using standard methods. Mean concentrations of As, Cr and Ni in soils are higher at impacted sites than control sites; while Pb and As concentrations in drainage exceeds the maximum contamination guideline values in drinking water. Using Cl- as a conservative tracer, As and Pb are adsorbing from water, while Cr and Ni are desorbing into water. In the food crops, bioaccumulation factors of As and Ni are profound at the impacted site than control sites; Except Cr in cocoyam at impacted sites, translocation factors are negligible in the food crops. Cr bioaccumulates in in cocoyam and plantain at the control site, while Ni bioaccumulates in only plantain at the impacted sites. Overall, the metal contamination is of concern in the receptors, except Pd in plants. Results from this study can be used for trace metals risk assessment in the environment.