<P> Metals in medicine are used in organic systems for diagnostic and treatment purposes . Inorganic elements are also essential for organic life as cofactors in enzymes called metalloproteins . When metals are scarce or high quantities, equilibrium is set out of balance and must be returned to its natural state via interventional and natural methods . </P> <P> Metals can be toxic in high quantities . Either ingestion or faulty metabolic pathways can lead to metal poisoning . Sources of toxic metals include cadmium from tobacco, arsenic from agriculture and mercury from volcanoes and forest fires . Nature, in the form of trees and plants, is able to trap many toxins and can bring abnormally high levels back into equilibrium . Toxic metal poisoning is usually treated with some type of chelating agent . Heavy metal poisoning, e.g., Hg, Cd, Pb, are particularly pernicious . </P> <P> Examples of specific types of toxic metals include: </P>

Describe the use of metal compound in medicine