Natural fluoride and trace metal levels of ground and surface waters in the greater Accra region of Ghana.

In a study of levels of fluoride and trace metals in ten different stations of both surface and groundwaters in the Greater Accra Region, Ghana, groundwaters were found to have lower pH than surface water, resulting in groundwaters having higher concentrations of dissolved ions. Groundwaters had higher fluoride levels than surface waters. The correlation coefficient for fluoride on total alkalinity and for fluoride on sodium were 0.56 and 0.27 respectively which implied that rock weathering played a minor role in the recorded fluoride enrichment of the underground waters. A likely mechanism for the higher underground fluoride levels could be bacterial decay of plant materials resulting in the release of fluoride to the underground waters. The levels of Cu, Cd, Pb and Zn fell within the expected background ranges. 90% of the sites had Mn levels above the detection limits in both underground and surface waters. 70% of boreholes in Accra plains had Fe levels higher than the WHO recommended limits of 0.3 mg/l for drinking water. Generally, underground waters had higher concentration of fluoride and trace metals than surface waters.

Environmental impact of the gold mining industry in Ghana.

X-ray Fluorescence (XRF) Analysis and Atomic Absorption Spectrophotometry (AAS) have been used in assessing heavy metal pollution from some gold mines in Ghana. The presence and levels of heavy metals in gold ore, gold tailings, inland waters, and river sediments have been determined. Using these techniques, the heavy metals: Cr, Mn, Fe, Cu, Zn, As, Pb, Rb, Sr, Y, Zr, and Nb were identified in some of the solid samples within a concentration range of 0.08 ppm--4.9%. However, the inland waters showed the presence of only Fe and Zn at levels of 0.08-2.4 micrograms/mL.