Mercury poisoning (also known as
hydrargyria or
mercurialism) is a type of
metal poisoning and a medical condition caused by exposure to
mercury or its
compounds. Mercury (chemical symbol Hg) is a
heavy metal occurring in several forms. All of these, except elemental liquid mercury (for which intravenous injection of a certain volume) produce toxicity or death with less than a gram. The damage done by elemental mercury is caused by blocking blood vessels. Mercury's zero
oxidation state Hg0 exists as vapor or as liquid metal, its mercurous state Hg
+ exists as
inorganic salts, and its mercuric state Hg
2+ may form either inorganic salts or
organomercury compounds; the three groups vary in effects. Toxic effects include damage to the brain, kidneys and lungs. Mercury poisoning can result in several diseases, including
acrodynia (pink disease), Hunter-Russell syndrome, and
Minamata disease.