http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?CMD=DisplayFiltered&DB=pubmed
[Amalgam risk assessment with coverage of references up to 2005]
[Article in German]
Mutter J, Naumann J, Walach H, Daschner F.
Institut fur Umweltmedizin und Krankenhaushygiene, Universitatsklinik Freiburg. joachim.mutter@uniklinik-freiburg.de
Amalgam, which has been in use in dentistry for 150 years, consists of 50 % elemental mercury and a mixture of silver, tin, copper and zinc. Minute amounts of mercury vapour are released continuously from amalgam. Amalgam contributes substantially to human mercury load. Mercury accumulates in some organs, particularly in the brain, where it can bind to protein more tightly than other heavy metals (e. g. lead, cadmium). Therefore, the elimination half time is assumed to be up to 1 - 18 years in the brain and bones. Mercury is assumed to be one of the most toxic non-radioactive elements. There are pointers to show that mercury vapour is more neurotoxic than methyl-mercury in fish. Review of recent literature suggests that mercury from dental amalgam may lead to nephrotoxicity, neurobehavioural changes, autoimmunity, oxidative stress, autism, skin and mucosa alterations or non-specific symptoms and complaints. The development of Alzheimer's disease or multiple sclerosis has also been linked to low-dose mercury exposure. There may be individual genetical or acquired susceptibilities for negative effects from dental amalgam. Mercury levels in the blood, urine or other biomarkers do not reflect the mercury load in critical organs. Some studies regarding dental amalgam reveal substantial methodical flaws. Removal of dental amalgam leads to permanent improvement of various chronic complaints in a relevant number of patients in various trials. Summing up, available data suggests that dental amalgam is an unsuitable material for medical, occupational and ecological reasons.
Publication Types:
Review
PMID: 15789284 [PubMed - indexed for MEDLINE]
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Neuro Endocrinol Lett. 2005 Oct;26(5):439-46. Related Articles,
Links
Mercury and autism: accelerating evidence?
Mutter J, Naumann J, Schneider R, Walach H, Haley B.
Institute for Environmental Medicine and Hospital Epidemiology,
University Hospital Freiburg, Germany. joachim.mutter@uniklinik-freiburg.de
The causes of autism and neurodevelopmental disorders are unknown.
Genetic and environmental risk factors seem to be involved. Because of an observed increase in autism in the last decades, which parallels
cumulative mercury exposure, it was proposed that autism may be in part caused by mercury. We review the evidence for this proposal. Several
epidemiological studies failed to find a correlation between mercury exposure through thimerosal, a preservative used in vaccines, and the risk of autism. Recently, it was found that autistic children had a higher mercury exposure during pregnancy due to maternal dental amalgam and thimerosal-containing immunoglobulin shots. It was hypothesized that children with autism have a decreased detoxification capacity due to genetic polymorphism. In vitro, mercury and thimerosal in levels found several days after vaccination inhibit methionine synthetase (MS) by 50%. Normal function of MS is crucial in biochemical steps necessary for brain development, attention and production of glutathione, an important antioxidative and detoxifying agent. Repetitive doses of thimerosal leads to neurobehavioral deteriorations in autoimmune susceptible mice, increased oxidative stress and decreased intracellular levels of glutathione in vitro. Subsequently, autistic children have significantly decreased level of reduced glutathione. Promising treatments of autism involve detoxification of mercury, and supplementation of deficient metabolites.