Background

Mercury in any form is poisonous, with mercury toxicity most commonly affecting the neurologic, gastrointestinal (GI) and renal organ systems. Poisoning can result from mercury vapor inhalation, mercury ingestion, mercury injection, and absorption of mercury through the skin. (See Etiology and Prognosis.)

Mercury has 3 forms: (1) elemental mercury, (2) inorganic salts, and (3) organic compounds. Perhaps the most deadly form of mercury is methylmercury. Only 2-10% of the ingested mercury is absorbed from the gut, and ingested elemental mercury is not absorbed at all; however, 90% of any methylmercury ingested is absorbed into the bloodstream from the GI tract. (See the images below.)