Investigating Soil and Water Contamination of Trace Metals in Tarkwa-Nsuaem Municipality, Ghana

Abstract

Tarkwa-Nsuam Municipality in the Western Region of Ghana has a long history of mining activity. In the Tarkwa area, small-scale mining is found all around; both in the forest and along the rivers. The study aimed at ascertaining the level of heavy metal pollution of water resources and soils in Tarkwa. The general objective of the project was to investigate the extent of health risk posed by heavy metals in mine drainage in the Tarkwa area. Soil and water samples were collected from 15 communities in the Tarkwa mining area and the concentrations in parts per million (ppm) of Mercury (Hg), Arsenic (As), Cadmium (Cd), and Lead (Pb) were determined in each sample using Instrumental Neutron Activation Analysis (INAA). The samples and the controls were irradiated in the Ghana Research Reactor-1 (GHARR-1) at the Ghana Atomic Energy Commission (GAEC), operating at 15KW at a thermal flux of 5´1011 n s-1 cm-2. Selected communities in the Tarkwa mining area, especially, Teberebie, Mile7, Akyempim, Mile 8, Mile 10½, and Mile 9 however,have their water sources fairly contaminated with elevated levels of arsenic, mercury, and cadmium due to ‘galamsey’ activities. Since most of the bore holes have very low yields and do not serve the purpose for which they are provided, it is recommended that the focus on construction of bore holes as a cooperate social responsibility of mining companies should be shifted to extension of pipe-borne water rather.