Literature has discussed this as a possible low-level hazard in the dental workplace. Metallic mercury is used in dental amalgams. Natural gas from certain sites has been reported to contain elemental mercury, and this exposure can occur in inspectors and maintenance or equipment workers at these sites. A ban in the United States on using mercurous nitrate in the hat-making industry was finally instituted in 1941.Įxposure to elemental mercury vapor occurs in the chloralkali industry during chlorine manufacturing. Lewis Carroll’s Mad Hatter from the children’s tale Alice in Wonderland is literature’s most famous victim of mercury toxicity. Mercury poisoning in hat makers resulted from prolonged exposure to mercury vapors in poorly ventilated factories. Inorganic mercury is used in photography, antiseptics, tanning processes, embalming, felt manufacturing, and wood preservation methods. Mercury is also found in electronic equipment, such as batteries, switches, rectifiers, compact fluorescent light bulbs, and mercury vapor lamps. Mercuric salts are used in gold, silver, and bronze plating processes. Toxicity of these and other organic compounds have only been recognized in this century.Įlemental mercury is used in barometers, thermometers, and gauges. Phenylic mercury compounds are less toxic than alkyl mercury compounds. Mercuric chloride is readily dissolved, ionized, and absorbed and is more toxic than the less soluble mercurous chloride. Mercury exists in three oxidative states and also forms univalent (mercurous) and bivalent (mercuric) compounds. Elemental mercury, also called quicksilver or liquid silver, is a liquid at room temperature. Mercury is extracted from ore called cinnabar (HgS) by a roasting process. Occasional cases are still reported today. Calomel, a type of inorganic mercury salt also known as “sweet mercury,” was used in laxatives and teething powders, the latter leading to outbreaks of “pink disease” or acrodynia, a hypersensitivity syndrome to elemental mercury that can occur in children ( 85 39). Today, dental amalgams, eye ointments, dermatological antiseptics, and hemorrhoidal sclerotics are still common medical sources of mercury. Teething powders and antihelminthics are now rarely made with mercury ( 80 85). Mercury and its salts were used as salves for syphilitics until the mid-20th century. Later, occupational hazards of mining metallic mercury were associated with a slow death. Mercury has been known to cause illness in artists, gilders, gold refiners, and workers using metals in dyes, cosmetics, and unguents since Roman times. Inorganic mercury is historically associated with environmental epidemics in Iraq and Japan, illness in occupational settings, and bizarre poisonings that have led to detective investigations.

Blood mercury is most appropriate for short-term exposures.

Twenty-four-hour urine mercury best assesses exposures to inorganic or elemental mercury.

Central nervous system effects are more common with organic mercury exposures.

Inorganic and elemental mercury exposures are more likely to cause peripheral nervous system complaints and findings.

Peripheral neuropathy from mercury exposure most commonly involves distal latency sensory slowing for short-term exposures, followed by motor slowing for more long-term exposures.The author has updated this article to reflect the current literature regarding peripheral nervous system disease and this commonly encountered metal. In this article, the author discusses common exposure sources, biological exposure indices, and clinical manifestations of mercury toxicity while focusing on mercury neuropathy for elemental, inorganic, and organic mercury. Mercury neuropathy is a recognized sequela of occupational or environmental exposure to one of the various forms of the heavy metal.

List of symptoms of mercury poisoning