What is mercury?
(Pronounced mer'kur-ee)

Mercury is a naturally occurring metal which has several forms. The metallic mercury is a shiny, silver-white, odorless liquid. If heated, it is a colorless, odorless gas.

Mercury combines with other elements, such as chlorine, sulfur, or oxygen, to form inorganic mercury compounds or “salts,” which are usually white powders or crystals. Mercury also combines with carbon to make organic mercury compounds. The most common one, methylmercury, is produced mainly by microscopic organisms in the water and soil. More mercury in the environment can increase the amounts of methylmercury that these small organisms make.

Metallic mercury is used to produce chlorine gas and caustic soda, and is also used in thermometers, dental fillings, and batteries. Mercury salts are sometimes used in skin lightening creams and as antiseptic creams and ointments.

No metabolic functions are known for which mercury is required. At high concentrations, mercury causes liver and kidney damage and neurological symptoms.19 Interest has grown in the possible ill health effects of mercury liberated from dental amalgam fillings as well as the increased consumption of fish contaminated with mercury.20,21 Hair is used as an index of internal accumulation of mercury provided it was not externally contaminated by exposure to mercury vapor.22,23

There is intriguing research correlating increased hair mercury levels with certain disease conditions. For instance, chronic mercury ingestion may be related to cardiovascular disease. Recent data suggests that a high intake of mercury from non-fatty freshwater fish and the consequent accumulation of mercury in the body is associated with an increased incidence of acute myocardial infarction, as well as death from cardiovascular disease in general. This correlation has been proposed to be due to the promotion of lipid peroxidation by mercury.24

Collaborative evidence for this finding comes from a Finnish case-controlled study in which higher numbers of dental fillings in individuals was associated with increased occurrence of acute myocardial infarction. 25

There is additional support that mercury from dental fillings results in increased body burden: scalp hair of British dentists and dental hygienists were 2-3 times higher in mercury than those of the support staff.26 A study of dentists, dental nurses, and assistants showed the average elevation of urine mercury levels were significantly related to the number of amalgam fillings the subjects had.27 Both hair and urinary mercury have been associated significantly with elevated titers of immune complexes containing oxidized LDL.28 Other evidence indicates that mercury can induce autoimmune disease both in humans and experimental animals.29 Mercury from dental fillings may also be a factor in multiple sclerosis, since hair mercury was found to be significantly higher in MS subjects compared to the non-MS controls.30 These studies also support the utility of hair and urine mercury measurement in situations of dietary, dental, or environmental exposure.

Sources: Vaccines, Adhesives, air conditioner filters, body powders, broken thermometer, cosmetics, dental fillings, diuretics, fabric softeners, felt, floor waxes-polishes, fungicides, industrial wastes, laxatives, mercurochrome, paints, photoengraving, psoriatic ointments, sea foods, sewage disposal, skin lightening cream, tanning leather, tattooing, wood preservatives.

References

19. Clarkson T. Mercury-an element of mystery [editorial]. N Engl J Med 1990;323:1137-39.

20. Lorscheider F, Vimy M, Summers A. Mercury exposure from "silver" tooth fillings: emerging evidence questions a traditional dental paradigm.

21. Al-Shaahristani H, Shibab K, Al-Haddad I. Mercury in hair as an indicator of total body burden. Bull World Health Org 1976; 53(Suppl):105-12.

22. Hac E, Krechniak J. Mercury concentrations in hair exposed in vitro to mercury vapor. Biol Trace Elem Res 1993;39(2-3):109-15.

23. Chang Y, Yeh C, Wang J. Subclinical neurotoxicity of mercury vapor revealed by a multi-modality evoked potential study of chloralkali workers. Am J Ind Med 1995;27(2):271-279.

24. Salonen J, Seppanen K, Nyyssonen K, Korpela H, Kauhanen J, Kantola M, et al. Intake of mercury from fish, lipid peroxidation, and the risk of myocardial infarction and coronary, cardiovascular, and death in eastern Finnish men. Circulation 1995;91(3):645-655.

25. Mattila K, Nieminem M, Valtonen V, Rasi V, Kesaniemi Y, Syrjala S, et al. Association between dental health and acute myocardial infarction. Brt Med J 1989:298:779-781.

26. Lenihan JM; Smith H; Harvey W. Mercury hazards in dental practice. Br Dent J 135;1973:365-396.

27. Zander D, Ewers U, Freir I, Brockhaus A. Mercury exposure of the population V: mercury exposure of male dentists and dental aids. Zentralbl Hyg Umweltmed (Ger) 1992;4:318-28.

28. Salonen J. 645-655.

29. Bigazzi P. Autoimmunity and heavy metals. Lupus 1994;3:449-453.

30. Siblerud R, Kienholzz E. Evidence that mercury from silver fillings may be an etiological factor in multiple sclerosis. Sci Total Environ 1994;142(3):191-205.