RADIOPHARMACEUTICALS AS MODERN METAL COMPLEXES Chelation is a chemical process in which a substance is used to bind molecules, such as metals or minerals, and hold them tightly so that they can be removed from a system, such as the body. In medicine, chelation has been scientifically proven to rid the body of excess or toxic metals: a person who has lead poisoning may be given chelation therapy in order to bind and remove excess lead from the body before it can cause damage. In the case of EDTA chelation therapy, the substance that binds and removes metals and minerals is EDTA. EDTA was first used in the 1940s for the treatment of heavy metal poisoning to remove heavy metals and minerals from the blood, such as lead, iron, copper, and ca...