Thimerosal
(50% mercury by weight) - used as preservative in vaccines.
Thimerosal is made with ethlymercurrichloride. The concentration
of this material in many vaccines is 0.01% thimerosal. This is equivalent
to 100,000 ppb thimerosal or 50,000 ppb mercury in the original
vaccine vial. We now know that primates exposed to injected thimerosal,
as opposed to equal amounts of ingested methylmercury, accumulate
twice as much of the inorganic fraction of mercury in the brain
(Burbacher et.al.). Inorganic mercury has a half-life of over 700
days in the brain and has been identified as the primary toxic agent
following the dealkylation of ethyl and methyl mercury (Charleston
et. al). This process leads to neuroinflamation and brain injury
and has recently been identified in autistic patients who have been
exposed to multiple doses of thimerosal (Vargas et. al).
The FDA is working to reduce or eliminate the use of thimerosal
in vaccines (see
FDA Thimerosal in Vaccines) and Institute of Medicine as reviewed
the use of thimerosal and found evidence on the health effects of
thimerosal inconclusive (see the IOM
web site).
Charleston J, Body R, Bolender R, Mottet N, Vahter M, Burbacher
T 1996. Changes in the number of astrocytes and microglia in the
thalamus of the monkey Macaca fascicularis following long-term subclinical
methylmercury exposure. Neurotoxicology 17:127-138
Wolfgang S, Mrak R, Griffin W 2004. Microglia and neuroinflamation:
a pathological perspective. Journal of Neuroinflamation 1:14
Vargus DL, Nascimbene C, Krishnan C, Zimmerman AW, Pardo Ca. 2005
Neuroglial activation and neuroinflamation in the brain of patients
with autism. Annals of Neurology 57:67-81.
Burbacher T, Shen D, Liberato N, Grant K, Cernichiari E, Clarkson
T. 2005. Comparison of blood and brain mercury levels in infant
monkeys exposed to methylmercury or vaccines containing thimerosal.
Environmental Health Perspectives. 113:1015-1021
REFERENCES / ADDITIONAL
INFORMATION
European, Asian, and International
Agencies
North American Agencies
- San
Francisco Bay Regional Water Quality Control Board
- establishes the San Francisco Bay Mercury Total
Maximum Daily Load (TMDL) (accessed: 26 Sept 2004)
Among other items numeric targets for mercury concentrations
in suspended sediment fish tissue, and berg eggs.
- Maine Department of Environmental Protection, Augusta,
Maine
Health Effects of Methylmercury with Particular Reference
to the U.S. Population Statement
of Deborah C. Rice, Ph.D. Hearing by the Senate
Committee on Environment and Public Works, July 29,
2003 (accessed: 17 May 2004). One of the best brief
statements on the health effects of mercury.
- Health
Canada - Mercury. Online. (accessed: 9 April 2003).
Health Canada provides information on the health effects
and environmental distribution of mercury.
- U.S.
Food and Drug Administration (FDA) - Advisory
on Methyl Mercury and Fish. Online. (accessed: 5 April
2003).
Site has recent FDA consumer information on methyl
mercury.
Non-Government Organizations
- Mercury Consensus Statement (pdf)
- Documents concerns about the health effects of mercury and encourages
U.S. EPA to take a more active role in reducing human and environmental
exposure.
- The Mercury Policy Project
(MPP). Online. (accessed: 5 April 2003).
"MPP works to raise awareness about the threat of mercury
contamination and promote policies to eliminate mercury uses,
reduce the export and trafficking of mercury, and significantly
reduce mercury exposures at the local, national, and international
levels."
- American Conference
of Governmental Industrial Hygienists (ACGIH®). Online.
(accessed: 5 April 2003).
ACGIH is a member-based organization and community of professionals
that advances worker health and safety through education and the
development and dissemination of scientific and technical knowledge."
- The Learning Disabilities Association of America (LDA), the
National Education Association (NEA), and the Arc of the United
States released a brochure
on March 14, 2005 that identifies mercury pollution as one of
the greatest threats facing developing fetuses, infants and young
children.
References
Clarkson, T. (1998). Methylmercury and fish consumption:
Weighing the risks. Can Med Assoc J, 158, 1465-1466.
Clarkson, T. W. (2002). The three modern faces of mercury. Environ
Health Perspect, 110 Suppl 1, 11-23. (EHP
on line) (accessed: 3 Aug 2005).
Gilbert, S. G., & Grant-Webster, K. S. (1995). Neurobehavioral
effects of developmental methylmercury exposure. Environ Health
Perspect, 6, 135-142. (EHP
on line). (accessed: 19 May 2005).
Hightower, J. M., & Moore, D. (2003). Mercury levels
in high-end consumers of fish. Environ Health Perspect,
111(4), 604-608
John Putman (1972). Quicksilver and Slow Death. National
Geographic 142(4), October, 1972, 507-527.
Kales, S. N., & Goldman, R. H. (2002). Mercury exposure:
current concepts, controversies, and a clinic's experience.
J Occup Environ Med, 44(2), 143-154.
Mahaffey KR, Clickner RP, Bodurow CC. Blood
organic mercury and dietary mercury intake: national
health and nutrition examination survey, 1999 and 2000.
Environ Health Perspect. 2004 Apr;112(5):562-70.
Martin, D. M., DeRouen, T. A., & Leroux, B. G.
(1997). Is Mercury Amalgam Safe for Dental Fillings?
Washington Public Health, 15(Fall), 30-32.
MMWR. (1996a). Mercury
exposure among residents of a building formerly used
for industrial purposes - New Jersey, 1995. Morbidity
and Mortality Weekly Report, 45(20), 422-424. Online.
(accessed: 5 July 2003).
MMWR. (1996b). Mercury
poisoning associated with beauty cream - Arizona, California,
New Mexico and Texas, 1996. Morbidity and Mortality
Weekly Report, 45(29), 633-635. Online. (accessed: 5
July 2003).
Prasad, V. L. (2004). Subcutaneous injection of mercury:
"warding off evil". Environ Health Perspect,
112(13), 1326-1328. (see ehponline.org)
Rice, D.C., Schoeny, R. & Mahaffey, K. (2003). Methods
and rationale for derivation of a reference dose for
methylmercury by the U.S. EPA. Risk Anal, 23, 107-15.
Zeitz, P., Orr, M. F., & Kaye, W. E. (2002). Public
health consequences of mercury spills: Hazardous Substances
Emergency Events Surveillance system, 1993-1998. Environ
Health Perspect, 110(2), 129-132.
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