heavy metal

Heavy metals are generally interpreted to include those metals with a specific gravity that is at least 5 times the specific gravity of water. Metals often mentioned from a toxicity standpoint include antimony, arsenic, bismuth, cadmium, cerium, chromium, cobalt, gallium, gold, iron, lead, manganese, mercury, nickel, platinum, silver, tellurium, thallium, tin, uranium and vanadium.