ABSTRACT
Mercury has no beneficial biological function, and its presence in living organisms is associated with cancer, birth defects, and other undesirable outcomes (Eisler 2000). The use of liquid mercury (Hg0) to separate microgold (Au0) particles from sediments through formation of amalgam (Au-Hg) with subsequent recovery and reuse of mercury is a technique that has been in force for at least 4700 years (Lacerda 1997a); however, this process is usually accompanied by massive mercury contamination of the biosphere (Petralia 1996). It is estimated that gold mining currently accounts for about 10% of the global mercury emissions from human activities (Lacerda 1997a).
