Estudio de la contaminación por metales pesados en la cuenca baja del río Guadiana

Abstract

This research develop a comprehensive geochemical study of the river basin waters and estuarine sediment developing the knowledge on environmental indicators that allow a better understanding of the environments affected by AMD. The results indicate that the waters of the basin are affected by AMD originated in old mine exploitations; highlight S. Domingos, Las Herrerias and Tharsis mines. The study of environmental change and sea level-rise over the past 13,000 years in the basin, suggests that mining activity is dated 4500 years ago (I I I Millennium), when the anthropogenic contribution of metals exceeded the natural sources. In the present, the sediments pose a moderate to considerable ecological risk over almost the entire estuary, due to the existence of metal concentrations in estuarine sediments exceeding the natural values (background), which are reflected in a homogeneous distribution called "historical diffuse pollution", as well as several punctual metals sources o f human activities.