Heavy Metal Pollution in Soil and Water in Some Selected Towns in Dunkwa-on-Offin District in the Central Region of Ghana as a Result of Small Scale Gold Mining

Jerome D A Kpan,Anukwah Gloria,Boadu Kwesi Opoku

doi:10.4236/jacen.2014.32006

Abstract

Illegal small scale gold mining popularly called “Galamsey” in our local communities is on the increase. This has led to concerns about the level of environmental pollution resulting from these mining activities. This work was conducted to determine the level of heavy metal contamination in the environment due to the activities of the small scale miners. This paper discusses the concentrations of some selected heavy metals—Hg, Pb, and Cu which were measured in 14 sampling sites in Dunkwa-on-Offin in the Central Region of Ghana, known for these activities. The heavy metal concentrations have been investigated for soil and water samples in the selected towns and compared with the relevant guidelines of the Environmental Protection Agency. The concentration of heavy metals was measured by using AAS. In most locations, the concentration for the investigated heavy metals far exceeded the concentration admitted by the guidelines. The mean concentration of Lead was 95.13 mg/Kg for soil and 190.27 mg/L in water; Copper was 63.26 mg/Kg in soil and 75.92 mg/L in water while Mercury was 140.87 ug/Kg in soil and 211.31 mg/L in water. The mean recorded concentrations in the sensitive areas exceeded greatly. Hence the levels of heavy metal contamination have spread beyond control.

Highlights

Small scale gold mining, popularly called “galamsy” in Ghana and other developing countries, is seen as a source of subsistence and a determinant of the environmental degradation [1]
In Ghana, small scale gold mining is set to be responsible for about 5% of the annual gold production
This gold mining of late has become unpopular as it is seen as the source of significant heavy metal contamination of the environment [2]

Summary

Introduction

Popularly called “galamsy” in Ghana and other developing countries, is seen as a source of subsistence and a determinant of the environmental degradation [1]. In Ghana, small scale gold mining is set to be responsible for about 5% of the annual gold production. This gold mining of late has become unpopular as it is seen as the source of significant heavy metal contamination of the environment [2]. Some of the impacts associated with this small scale gold mining include the destruction of vegetation, land degradation and the pollution of water bodies. It’s reported that in a prospecting work in a field, a pit that was dug revealed the presence of mercury in the soil [6]. Et al (2010) [7] reported high levels of mercury and zinc content in the top soil of towns in Wassa West. The levels of the concentration, decreased with distance from the main mining centers and extended beyond most probably due to aerial dispersion of the metal from mining areas

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Results