Geochemical background of some potentially toxic and essential trace elements in soils at the Nadowli District of the Upper West Region of Ghana

Use of universal baseline values such as continental crustal averages to assess related health issues from trace elements in environmental soils may be fraught with challenges because the method only considers unmineralized... [ view full abstract ]

Use of universal baseline values such as continental crustal averages to assess related health issues from trace elements in environmental soils may be fraught with challenges because the method only considers unmineralized rocks and soils in the determination of average crustal abundances or background values. Likewise legislated guideline values are also for specific geographic locations in the environments. None of these takes into accounts the human activities at a particular local community as the environmental conditions have dire influence on trace element mobility, concentrations and storage in the surface soils. The 29 trace element samples collected from soils up to the depth of 20 cm were analysed using ICP-MS analytical technique. The results of the trace element concentrations were analysed statistically and graphically to isolate sets of background values that are better suited locally to identify and assess trace elements contaminated and depleted areas. Local background values of 15.00 ppm was estimated for As, 0.02 ppm for Cd, 0.01 ppm for Hg, 35.0 ppm for Zn, and 20.0 ppm for Cu and 0.40 ppm for Se. For clean-up goals in environmental legislation and for the assessment of trace elements impacts on health in Nadowli District these background values should be used.