Environmental Impact of Small-scale and Artisanal Gold Mining in Southern Ecuador

摘要

Small-scale gold mining in southern Ecuador is causing considerable environmental impacts, the most important of which are related to the discharge of metals, metalloids and cyanide into adjacent rivers. In the rivers, these contaminants are generally not present in water-soluble forms, but are instead associated with suspended particles and river bed sediment. However, elevated levels in biota show these contaminants to be readily bioavailable. These results suggest a need to consider the suspended and sediment phases when evaluating water-quality impacts, and in setting appropriate environmental water-quality standards. Contaminant discharges, are almost entirely caused by inadequate management of the waste products derived from mining and processing activities, indicating a failure of policy and public supervision to control the mining activities, as well as a general difficulty in achieving good environmental performance among small-scale miners. These findings suggest that Ecuadorian policy needs to develop to enable small scale and artisanal miners to become larger scale.