Chelation (pronounced key-LAY-shun) is considered the best-known treatment for heavy metal poisoning or toxicity. Chelation therapy involves oral intake or intravenous injections of a chemical compounds such as EDTA (ethylene diamine tetra-acetic acid) or DMPS (2,3 dimercaptopropane-1-sulfonate). The chelating agents are thought to work by forming an insoluble complex with the metal that is firmly bound inside cells as well as binding to minerals (calcium) in the blood so that the heavy metals can be excreted in the urine. Because EDTA can reduce the amount of calcium in the bloodstream, and because calcium is found within the plaque that lines diseased blood vessels, it could prove helpful with treating certain cardiovascular diseases. Physician monitoring is essential.