You describe Geier et al (2009) as a review when it is titled "A prospective study of prenatal mercury exposure from maternal dental amalgams and autism severity." A review article normally examines all the published evidence for and against a hypothesis. Geier et al (2009) is a study of human subjects that is testing the hypothesis that there is a connection between mercury exposure and autism. We can argue about the merits of this particular study but I hope we can agree that it is not a review.
This is important because you quote directly from the introduction to suggest that based upon a review of the literature Geier et al (2009) found that,
"Mercury from maternal amalgam fillings leads to a significant increase of mercury concentration in the tissues and the hair of fetuses and newborn children. Furthermore, placental, fetal, and infant mercury body burden correlates with the numbers of amalgam fillings of the mothers. Finally, mercury levels in amniotic fluid and breast milk correlate significantly with the number of maternal dental amalgam fillings."
No they did not. Geier et al (2009) did not examine "mercury concentration in the tissues and the hair of fetuses and newborn children." Nor did they examine the correlation between "placental, fetal, and infant mercury body burden [and] the numbers of amalgam fillings of the mothers. Nor did they test whether "mercury levels in amniotic fluid and breast milk correlate significantly with the number of maternal dental amalgam fillings."
What they did was to take 100 people with an ASD and look for correlations between the severity of their autism and the number of dental fillings their mothers had, either prior to or during their pregnancy. They acknowledge that they did not measure mercury exposure but instead took the number of fillings as a proxy measure of exposure. We do not know when these fillings occurred in relation to their pregnancies and we do not know whether they used mercury amalgams. And, neither it seems, do the authors.
"In addition, since information on the numbers of fillings but not information on: their size (surface area), the nature of the amalgam alloy used, or the location of the amalgam in the mouth was available to researchers in this study, the effects of: the amalgam size (surface area) of the fillings; the intrinsic mercury release rates for the amalgam composition installed; and chewing friction, are confounders that further reduce the magnitude of the observed effects." (Geier et al 2009)
All we can conclude from Geier et al (2009) is that there may be a relationship between maternal dental health and the severity of ASD. Given that Dr Geier already has a reputation for misrepresenting the facts, http://neurodiversity.com/weblog/article/217/ for you to misrepresent him even further does nothing to support your case.
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You describe Geier et al (2009) as a review when it is titled "A prospective study of prenatal mercury exposure from maternal dental amalgams and autism severity." A review article normally examines all the published evidence for and against a hypothesis. Geier et al (2009) is a study of human subjects that is testing the hypothesis that there is a connection between mercury exposure and autism. We can argue about the merits of this particular study but I hope we can agree that it is not a review.
This is important because you quote directly from the introduction to suggest that based upon a review of the literature Geier et al (2009) found that,
"Mercury from maternal amalgam fillings leads to a significant increase of mercury concentration in the tissues and the hair of fetuses and newborn children. Furthermore, placental, fetal, and infant mercury body burden correlates with the numbers of amalgam fillings of the mothers. Finally, mercury levels in amniotic fluid and breast milk correlate significantly with the number of maternal dental amalgam fillings."
No they did not. Geier et al (2009) did not examine "mercury concentration in the tissues and the hair of fetuses and newborn children." Nor did they examine the correlation between "placental, fetal, and infant mercury body burden [and] the numbers of amalgam fillings of the mothers. Nor did they test whether "mercury levels in amniotic fluid and breast milk correlate significantly with the number of maternal dental amalgam fillings."
What they did was to take 100 people with an ASD and look for correlations between the severity of their autism and the number of dental fillings their mothers had, either prior to or during their pregnancy. They acknowledge that they did not measure mercury exposure but instead took the number of fillings as a proxy measure of exposure. We do not know when these fillings occurred in relation to their pregnancies and we do not know whether they used mercury amalgams. And, neither it seems, do the authors.
"In addition, since information on the numbers of fillings but not information on: their size (surface area), the nature of the amalgam alloy used, or the location of the amalgam in the mouth was available to researchers in this study, the effects of: the amalgam size (surface area) of the fillings; the intrinsic mercury release rates for the amalgam composition installed; and chewing friction, are confounders that further reduce the magnitude of the observed effects." (Geier et al 2009)
All we can conclude from Geier et al (2009) is that there may be a relationship between maternal dental health and the severity of ASD. Given that Dr Geier already has a reputation for misrepresenting the facts, http://neurodiversity.com/weblog/article/217/ for you to misrepresent him even further does nothing to support your case.
Mike Stanton
September 24, 2011 - 3:50pmThis Comment
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