Chemical Forms of Mercury, Cadmium, and Zinc in Natural Waters

Published information on the chemical forms of mercury, cadmium, and zinc in natural wet environments (water, suspended or colloidal particles, deposits, biota) and on their toxicity and biological interconversions is generalised and critically discussed, and the mechanisms for the absorption and expulsion of these materials through the appropriate phase separation surfaces are considered. The chemical forms of these and other trace metals are shown to be the controlling factor in their geochemical cycles and their anthropogenic effects on ecological equilibria in the natural environment. 224 references.