Assessment of the Water Quality and Toxicological Effects of Toxic Metals in Selected Water Bodies around Gold Mining Areas in Ghana

The study aimed to assess the water quality and toxicological effects of some toxic metals in selected water bodies around artisanal gold mining areas in Ghana. This study investigated the toxicological effects of heavy metals and the water quality of mining-affected water bodies in five mining areas of Ghana, focusing on heavy metals such as arsenic (As), cadmium (Cd), mercury (Hg), lead (Pb), and zinc (Zn). These metals were assessed on the basis of their distribution, concentration, and human and environmental risks, alongside key physicochemical characteristics (organic matter, pH and conductivity) known to influence the interactions and dynamics of heavy metals in surface water and sediment matrices. The cation exchange capacity (CEC), which influences metal adsorption and mobility in sediment, was also explored. Forty (40) composite samples were digested and analysed for heavy metals (As, Cd, Hg, Pb, and Zn) via ICP-MS. The sediment pH ranged from 5.89 to 6.78 mg/kg, and the water pH ranged from 5.89 to 6.79. The electrical conductivity (EC) values of the sediments peaked at 1241 µS/cm. The As level in the water exceeded the WHO limit (0.01 mg/L), reaching 0.075 mg/L in Obuasi, whereas the zinc concentration peaked at 0.401 mg/L in Kenyase. The arsenic and zinc concentrations in the sediment were highest in Obuasi at 0.6 mg/kg and 0.4 mg/kg, respectively, suggesting substantial contamination and environmental risks. These findings align with broader studies on the behaviour of heavy metals in aquatic ecosystems, where adsorption‒desorption dynamics are regulated by sediment properties such as mineralogy, specific surface area, and cation exchange capacity. These interactions indicate the urgent need for targeted strategies to mitigate health and environmental risks.