Thursday, February 23, 2006

Problems with the Mercury Hypothesis

I'll start this blog with some criticism of the hypothesis that mercury poisoning is responsible for autism across the board. Some parents who propose this hypothesis appear to be quite belligerent and eager to demonstrate their hate for autism and autistics (see hatingautism.blogspot.com). Anyone who disagrees is labeled "mercury poisoned" as well, and presumed to be inferior (just as I can only assume they see their own children). Disagreements are thus explained away as a lack of reasoning skills. As appalling as this is, it is not the basis of my criticism.


I could analyze in detail the studies that demonstrate a link and those that don't, comparing their methodology. But this has been done [ref][ref][ref].


What I intend to do is point out a number of well known facts about autism and mercury toxicity which are totally inconsistent with the hypothesis. At the very least, there are no mercury toxicity-based theories that attempt to explain them.


  1. There's no mechanism by which mercury could cause savant skills to emerge.
  2. The most severe symptoms of mercury poisoning include such things as kidney damage, burning mouth, and perspiration. These are not symptoms of autism, even in a minority of cases.
  3. Mercury poisoning cannot account for neuroanatomical differences observed in early childhood, such as white and grey matter volume differences, increased head circumference, and differences in neuron size and density.
  4. Mercury poisoning cannot account for increased false memory discrimination, information processing advantages, and other cognitive differences that have been documented.
  5. It has been hypothesized that autistic children have a genetic liability in their body's mercury metabolism, having to do with the APO-E4 protein. This, however, would mean that a good portion of the siblings and parents of autistic children who had been themselves vaccinated with thimerosal should also be autistic. This is not the case. In fact, twin and sibling studies suggest that a single genetic variation is not sufficient to cause autism.
  6. Additionally, several different alleles have been linked to autism, and these are prevalent in the general population. None of the alleles that have come up in genome-wide scans are related to mercury disposal in any way.
  7. Objectively diagnosable conditions which look like autism have a purely genetic etiology. These include Fragile-X, Tuberous Sclerosis, and Rett Syndrome.
  8. There are no reports of adult autistics running to get chelated, and some of them are OK with their autism, which would seem to be a strange way to experience being poisoned.


This, of course, does not mean that the symptoms of autism couldn't be amplified by a small amount of mercury poisoning, or that some diagnosed cases may be caused by mercury poisoning. But it is unethical and scientifically ludicrous to say that autism and mercury poisoning are the same thing. It is also silly to suggest that chelation is an autism treatment, as it does nothing other than treat heavy metal toxicity. And it is just wrong to diagnose and label a child or an adult as mercury poisoned without any medical tests to back up the assertion.

4 comments:

  1. I have always thought it was a ridiculous argument to take up in the first place. Just suppose that the increase in autism is caused by the mercury in vaccines. What difference will it make anyway? The Federal Government will never plead mia culpa and even if they did, it doesn't turn back time.

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  2. Just suppose that the increase in autism is caused by the mercury in vaccines. What difference will it make anyway?

    It would be helpful in devising a treatment, but you're right in that thimerosal has already been removed from vaccines.

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  3. Hi Joseph,
    I enjoyed your excellent comments on my blog and others and I'm very pleased to see that you've decided to start a blog of your own. I look forward to reading more of your insightful thoughts.

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  4. I enjoyed your excellent comments on my blog and others and I'm very pleased to see that you've decided to start a blog of your own.

    Thanks. Blogs appear to be a good way to let out thoughts I'd usually just bore my wife to death with :)

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