mercury

mercury

 (Hg) [mer´ku-re]

a chemical element, atomic number 80, atomic weight 200.59. (See Appendix 6.) Mercury forms two sets or classes of compounds: mercurous, in which a single atom of mercury combines with a monovalent radical, and mercuric, in which a single atom of mercury combines with a bivalent radical. Mercury and its salts can be absorbed by the skin and mucous membranes, causing chronic poisoning (see mercury poisoning). The mercuric salts are more soluble and irritant than the mercurous.

ammoniated mercury a compound used as an antiseptic skin and ophthalmic ointment. It should be applied with caution, as excessive use may irritate the skin and cause dermatitis.

mercury bichloride an extremely poisonous compound formerly used in treatment of syphilis but now used only as a disinfectant.

mercury poisoning acute or chronic disease caused by exposure to mercury or its salts; an important aspect is its toxic effect on the brain, causing impaired judgment, memory loss, sleeplessness, and nervousness. The acute form, due to ingestion, is marked by severe abdominal pain, metallic taste in the mouth, vomiting, oliguria or anuria at onset, followed by bloody diarrhea, and corrosion and ulceration of the entire digestive tract. The chronic form, due to absorption by the skin and mucous membranes, inhalation of vapors, or ingestion of mercury salts, is marked by stomatitis, metallic taste in the mouth, a blue line along the border of the gum, sore hypertrophied gums that bleed easily, loosening of the teeth, excessive salivation, tremors and incoordination, and psychiatric symptoms including abnormal excitability, anxiety, and social withdrawal. A common cause of chronic mercury poisoning is the ingestion of contaminated fish. Because of this, some fishing areas are posted with signs recommending limiting consumption of fish caught there. See also minamata disease.

Treatment. Treatment consists of removal of the source of exposure and administration of a chelating agent. Exchange transfusions and removal of mercury by surgery are options in selected patients. Consultation with a toxicologist is warranted.

Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

mer·cu·ry (Hg),

(mĕr'kyū-rē),

A dense liquid metallic element, atomic no. 80, atomic wt. 200.59; used in thermometers, barometers, manometers, and other scientific instruments; some salts and organic mercurials are used medicinally; care must be followed with its handling; ¹⁹⁷Hg (half-life of 2.672 days) and ²⁰³Hg (half-life of 46.61 days) have been used in brain and renal scanning.

Synonym(s): hydrargyrum, quicksilver

[L. Mercurius, Mercury, the god of trade, messenger of the gods; in Mediev. L., quicksilver, mercury]

Farlex Partner Medical Dictionary © Farlex 2012

mercury

A liquid metallic element (atomic number 80; atomic weight 200.59) often obtained from cinnabar, a major mercury ore. Mercury preparations used in healthcare have minimal toxicity and mercury-based agents have been used as diuretics, topical antiseptics and in dental amalgams, and are thought to be relatively safe; the practice of removing dental amalgams is believed by toxicologists to cause a marked short-term increase in mercury levels. The cardioprotective effect of n-3 fatty acids may be reduced by the high mercury content of fish.

Alternative dentistry
See Dental amalgam.

Homeopathy
Merc sol, see there; Mercurius solubilis.
 
Toxicology
A highly toxic heavy metal widely used in household products (e.g., as a fungicide in latex paints) which is absorbed via skin and lungs.

Clinical findings
• Inorganic mercury causes nausea, diarrhoea, renal toxicity.
• Organic mercury causes neuromuscular defects (e.g., loss of co-ordination), myalgias, brain dysfunction and “mad hatter” disease (which may be misinterpreted as a mental disorder).

Specimen
24-hour urine.

Ref range
0–20 µg/L.
 
Toxic range
> 150 µg/L.
 
Method
Atomic absorption spectrophotometry.

Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.

mer·cu·ry

(Hg) (mĕr'kyūr-ē)

A dense, liquid metallic element, atomic no. 80, atomic wt. 200.59; used in thermometers, barometers, manometers, and other scientific instruments; some salts and organic mercurials are used medicinally; ¹⁹⁷Hg (half-life of 2.672 days) and ²⁰³Hg (half-life of 46.61 days) have been used in brain and renal scanning.

Medical Dictionary for the Health Professions and Nursing © Farlex 2012

mer·cu·ry

(mĕr'kyūr-ē)

A dense liquid metallic element; used in thermometers, barometers, manometers, and other scientific instruments; some salts and organic mercurials are used medicinally; must be handled with care.

Medical Dictionary for the Dental Professions © Farlex 2012