The Mercury-Autism Link V
Bill Long 8/27/08
The 2003 Holmes Study; Brant's 2007 Refutation
The NHANES study was helpful in establishing some general baseline figures for mercury concentrations in children ages 1-5 and pregnant women in the USA in 1999-2000. What it didn't do, however, was to break out figures for autistic v. non-autistic children or look at other issues (such as dental amalgams, vaccines, antibiotics) than mercury level as it correlated to fish consumption. Thus, when Amy Holmes, Mark Blaxill and Boyd Haley published "Reduced Levels of Mercury in First Baby Haircuts of Autistic Children" in 2003, they were exploring virgin territory. At this point (2008) serious questions have been raised regarding their procedures and results, but let me give you their description of what they tried to do, because this study established a sort of "first attempt" at a comparison of mercury levels in autistic and neurotypical children. Their abstract states:
"First baby haircut samples were obtained from 94 children diagnosed with autism using Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM IV) criteria and 45 age- and gender-matched controls. Information on diet, dental amalgam fillings, vaccine history, Rho D immunoglobulin administration, and autism symptom severity was collected through a maternal survey questionnaire and clinical observation. Hair mercury levels in the autistic group were 0.47 ppm versus 3.63 ppm in controls, a significant difference."
Indeed, if these figures were true, they would be quite astonishing and possibly very illuminating for further research for they suggest that there is an eight-fold difference in mercury concentration between the two populations. This would fuel speculation that mercury was the "culprit" in many autism cases and add to the growing sense, in 2003, that vaccines-laden with thimerosal (which had been removed from new stocks of vaccines, except for influenza, by 2001) were responsble, or at least contributed to, the "autism epidemic." It would also support the idea that one of the basic problems with autistic children was their inability to excrete mercury (of which mercury concentration in hair may be an index). Thus, this would pave the way for chelation therapies, which are useful for removing heavy metal concentrations from the body.
But the study made two other claims that also would be subject to further examination in ensuing years. They said:
"Within the autistic group, hair mercury levels varied significantly across mildly, moderately, and severely autistic children, with mean group levels of 0.79, 0.46, and 0.21 ppm, respectively."
This suggests a correlation between mercury levels and severity of autism. The more severe your case of autism, the lower your levels of mercury in hair samples. Such data, if true, could also support the notion of autistic children having difficulty in excreting mercury. Finally, the study claimed that there were correlations between mercury level in hair and a variety of other measures. They say:
"Hair mercury levels among controls were significantly correlated with the number of the mothers' amalgam fillings and their fish consumption as well as exposure to mercury through childhood vaccines, correlations that were absent in the autistic group."
Thus, if these results could be replicated, they would represent a real "breakthrough" in autism studies. Replication would show that the severity of autistic symptoms was correlated with an increased level of unexcreted mercury in the body; and that many mercury-bearing substances were probably the "culprit." So important was it to verify these results that Prof. James Adams of Arizona State University led a team of researchers to try to replicate this study. Dr. Adams' results were published just this week. I deal with the study in this essay.
The Omnibus Autism Proceeding and the Holmes Study
Meanwhile, on the legal front, the Omnibus Autism Proceeding ("OAP") began in Washington DC in 2007. This is an action presided over by Special Masters appointed by the Court of Federal Claims, to hear representative cases of the more than 4,800 claims filed under an 1980s law (the National Vaccine Injury Compensation Act) claiming that the thimerosal in vaccines as well as the MMR vaccine had caused or significantly contributed to autism in many children. The OAP has been conducted under three theories, and for each of the theories there have been three test cases. Conducted in the summer of 2007 were the cases under "Theory 1"--that the MMR vaccine in combination with thimerosal-containing vaccines can cause autism. "Theory 2" cases, that thimerosal-containing vaccines alone can cause autism, was heard earlier in 2008; and "Theory 3" cases, which argue that the MMR vaccine alone can cause autism, will be heard in Fall 2008.
In the first of these cases, the Cedillo case, nearly 3,000 pages of testimony was given on the "joint MMR/thimerosal" issue. I will review here, and principally in the next essay, the testimony of probably the most significant expert for the position that the combination of MMR/Thimerosal cannot cause autism. I will taking the time to go through the leading points of Dr. Jeffrey Brent's testimony because I think it not only offers a challenge to those who claim that mercury poisoning or inability to excrete mercury lies at the base of problems of many autistic children but it also has a significant gap in it, in my judgment, that is increasingly being explored in 2008 and will be on the agenda for the future.
Dr. Brent, a Professor of Pediatrics and Internal Medicine at the University of Colorado Health Sciences Center (Denver) and principal in Toxicology Associates, testified for nearly an entire day on the 10th day of the first proceeding, June 22, 2007. He testified not only as an expert in toxicology, which he defined as "the science of the adverse effects of chemical substances on living things," but he also is a medical toxicologist. It is, as he says, a term attached to a "whole series of very formal and official requirements..." and that a medical toxicologist only becomes one after taking a special two-year training in the field and then becoming certified in it. At present there are no more than about 260 certified medical toxicologists in the US.
Obviously the defense attorneys wanted to highlight Dr. Brent's qualifications because he was going to attack the point that a combination of the MMR vaccine as well as thimerosal in some vaccines could have caused Michelle Caudillo's autism. The next essay reviews his testimony.
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