Faroe Islands Study
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This study is included as an example where effects were measured at levels previously thought to be safe, so we cannot assume that levels of exposure to mercury from amalgam are safe particularly since it is acknowledged that studies have not been performed for the appropriate end points (neurotox) on the appropriate at-risk population (people with amalgam). Secondly, because the mechanism of absorption into the brain is the same for methyl and elemental (vapour) mercury, it is likely that mercury vapour will accumulate as easily in the brain.
The publication of this widely discussed Faroe Islands study should have a dramatic impact on evaluation of mercury exposure to unborn babies. Obviously, the adverse effect is not detectable at birth, and shows a dramatic impact on quality of life for the affected individuals. The significance to dentistry of this study is that methyl mercury and mercury vapour are the two forms of mercury that readily penetrate cell membranes and accumulate in tissues of unborn babies. Methyl mercury is derived primarily from consumption of fish and seafood, whereas the primary contributor of mercury vapour to human body burdens comes from dental fillings.
This research, (50) also reported on in the Lancet, adds to the concern about effects of low levels of mercury on children's development raised some time ago by Marlowe et al.(52) Their research found that low mercury levels correlated significantly and negatively with full scale, verbal, and performance IQ and six subset scores of the intelligence test. They concluded that a continuing re-examination of mercury exposure was needed because mercury levels previously thought harmless and routinely encountered in the environment may be associated wth intellectual decrements. Their concern about the adverse effects of low levels of mercury on the development process was influenced by several points. Firstly, the effects could signal the early stages of an ongoing toxic process that becomes more disabling with age. Animal studies have shown that animals exposed at an early age showed only slight retardation but by adulthood overt neurological impairment, measured by co-ordination problems became evident. As the animals approached middle age, central nervous system involvement became obvious and behavioural tests were no longer needed to identify exposed animals. When one appreciates the fact that mercury amalgam fillings release mercury vapour over the entire life of the filling, the implications of this research become even more significant. The second reason was that there is considerable individual variation to mercury, a variation that applies to most metal pollutants. A pollutant that produces subtle behavioural alterations in many children may produce a severe learning disorder in those who are especially susceptible because of genetic or other factors. The third reason was that behavioural effects of children affected by mercury could make the child difficult to parent or instruct leading to tension that became aggravated over time. The difficulty in instructing would also presumably add to the problems caused by the neurological impairment already present. The implications of this study and the Faroe Islands study need to be considered in conjunction with Drasch's recent studies (57, 86)
Prof. Draschs research has demonstrated that mercury from amalgam will be similarly transported. Professor Drasch in 1994 demonstrated that the level of mercury in the foetus, new-born and young child is directly proportional to the number of amalgams in the mothers mouth. It therefore does not matter if the woman falls pregnant 10 years after having her amalgams placed, the foetus is still exposed to both mercury and methyl mercury.
Prof. Drasch stated "Future discussion on the pros and cons of dental amalgam should not be limited to adults or children with their own amalgam fillings, but also include foetal exposure. The unrestricted application of amalgam for dental restorations in women before and during the child-bearing age should be reconsidered." In another paper he also concluded: "These results show that amalgam fillings release silver as well.........Silver is a reliable marker for the fact that the elevated concentrations of inorganic mercury found in tissues of people with amalgam filings, derive mainly from these fillings and not from other theoretically possible sources."
Clearly, there is no place for mercury amalgams in the mouths of children, young and old, pregnant or fertile women or nursing mothers.