For centuries, artisanal and industrial activities have left many soils polluted with excessive levels of heavy metals such as zinc, cadmium, copper and lead, posing a threat to the environment and human health. Cleaning up polluted sites is often difficult and expensive, especially when larger area s are affected. As a result, many sites need to be managed in a way that prevents pollutants from washing away into groundwater or neighboring ecosystems. ...read more read less