ISSN 2756-3251
Advanced Journal of Environmental Science and Technology ISSN 7675-1686 Vol. 9 (6), pp. 001-007, June, 2018. © International Scholars Journals
Full Length Research Paper
Trace elements contamination of soils around gold mine tailings dams at Obuasi, Ghana
P. Antwi-Agyei1*, J. N. Hogarh1 and G. Foli2
1Department of Environmental Science, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
2Department of Earth and Environmental Science, University for Development Studies, P. O. Box 24, Navrongo Campus; Navrongo, Ghana.
Accepted 18 January, 2018
Abstract
This study investigated the issue of tailings dams as a potential source of trace elements contamination in soils at the Obuasi gold mine in Ghana. Soil samples taken from depths of up to 12 cm and within a radius of 400 m from the tailings dams (active and decommissioned), were analysed for As, Cu, Pb and Zn using atomic absorption spectrometry. Average concentrations of As, Cu, Pb and Zn in soils around the active tailings dams were respectively 581±130, 39.64 ± 3.02, 24.22 ± 2.62 and 72.64 ± 8.01 mg/kg. Soils in the vicinity of the decommissioned tailings dam registered increased values - 1711 ± 172, 71.44 ± 5.27, 38.67 ± 3.59 and 168.1 ± 36.2 mg/kg for As, Cu, Pb and Zn respectively. Both types of tailings dams impacted adjoining soils with greater concentrations of the trace elements when compared to undisturbed control soils. Arsenic was above the Netherlands intervention value of 55 mg/kg dry weight, even in control soils. The following trend of accumulation was observed in the soils: As>Zn>Cu>Pb. Improved tailings management strategies, among other factors, might have influenced the reduced level of trace elements contamination at the active tailings dams’ site.
Key words: Gold mining, tailings dam, trace elements, soil, Obuasi.