I've had a number of exchanges with Jim Laidler and although I think
he is an intelligent man, I think he has become embittered and is not
entirely rational on these issues. I think that goes for a number of
the people on QuackWatch. So while I applaud those of you who
participate there, I don't consider it worth scarce time to spend too
much time debating these people.

That said, Laidler does tend to raise pertinent issues, he simply
twists them in bizarre ways. Remember that Laidler wrote the original
DAN! chelation protocol. As I understand it, after chelation with his
child proved less successful than his expectactions, he became
disillusioned. So now all of us are quacks. Go figure.

But some quick answers to his questions are as follows.

1. I never testified before Congress. I did present some analysis to
the IOM in July 2001. My analysis included a rough attempt to
estimate thimerosal exposure in a "typical" US child based on some
statistics I collected on vaccine coverage rates and market shares. I
then compared rising US vaccine-based mercury exposures to California
autism rates. This was not a perfect method but the best I could do.
I argued that the data showed that the mercury theroy was consistent
with available facts. I never argued anything more for the model and
never attempted to publish it (Stehr-Green and colleagues found it
sufficiently compelling to print it in order to attack it later). But
my data (and simple exposure model) was in no way intended to specify
the timing of exposure "plateaus" or any related effects. I didn't
make any represenations to that effect. More importantly, we don't
know at all how vaccine inventories have been managed nor do we know
how the exposures may have been distributed across the country. Jim
is torturing my model beyond its limits to make this point.

2. There are few reliable statistics on prevalence trends for
disorders that might be related to autism. There is also no clear
reason that mental retardation rates should rise with post natal
mercury exposure. This point is a non-sequitor.

3. Different kinds of marcury exposure lead to widely variable kinds
of developmental disorders depending on the type, timing, amount and
pathway of the exposure. Acrodynia, for example, presents as an
entirely different disease than Congenital Minamata Syndrome even
thought the "mercury" exposures are only a matter of months apart
(see Blaxill, Redwood and Bernard in Med Hypth for more on this).
There is no basis to expect that the specific pattern of mercury
exposure in autism must necessarily produce ataxia.

4. The Danish data is garbage and the appearance of increases there
is largely an administrative effect, due to increased registrations.
We don't have good data on autism rates in many countries. What we
have, I have described in my review article ("What's Going On? the
question of time trends in autism." PHR).

FWIW, Jim Laidler also believes that autism has been around forever
and that Kanner didn't find a rare disease, it was simply something
nobody noticed. Someone should ask Laidler to prove that autism rates
have not risen in the same way the data clearly show. For those who
would like to believe that these rates are an artifact of rising
awareness, I suggest that a very large burden of proof lies on them
to prove the facts are an illusion. And he should be asked to explain
why all those who have looked for the "hidden horde" have always
failed to find any evidence of it.

Mark

--- In EOHarm@yahoogroups.com, Craig Garfinkel <cdgarfinkel@y...>
wrote:
> Dr. James Laidler is a QuackWatch member who strongly
> denies any thimerosal connection. What makes James
> interesting is the fact that he has two autistic sons
> and intially was a strong proponent of the DAN
> protocol - himself becoming a DAN doctor. At some
> point he had a change of heart. He felt the protocol
> wasn't helping his son and now attacks the DAN
> movement and the thimerosal connection.
>
> He just posted some questions that he claims are the
> primary reasons why he doesn't support a link. Can
> someone respond to these, preferably with data? I
> doubt that he would ever switch sides at this point
> but you never know given his history and his personal
> interest in this debate. He seems to be well
> respected and would make for a good ally.
>
>
> "Any hypothesis that postulates a causal connection
> between autism and thimerosal has to have answers to
> the following questions:
>
> [1] Why didn't the autism prevalence rate for US 6
> year-olds reach a plateau by 2000, since the number of
> thimerosal-containing vaccines given to
> children had reached a plateau in the early 1990's
> (1994, according to Mark Blaxill's testimony before
> Congress in 2002 [Congressional Record - House,
> November 22, 2002, page H9108])?
>
> [2] Why hasn't the prevalence of other neurological
> disorders of young children (e.g. mental retardation)
> risen at the same time and pace as autism?
>
> [3] Mercury toxicity is characterized by cerebellar
> damage, leading to a characteristic motor ataxia. Why
> is this not a regular feature of autism?
>
> [4] Why hasn't autism prevalence fallen in countries
> that removed thimerosal earlier? Even if you dispute
> the Madsen et al study's comparison of autism
> rates from 1971 to 2000, you still need to explain why
> the Danish autism prevalence in 2001 was higher than
> 2000 and 2002 was higher than 2001.
>
> Again, I'm not saying that these questions can't be
> answered, just that they haven't been, yet. When I've
> asked these questions, I seem to mostly get either
> silence or hostility - the assumption seems to be that
> I'm being deliberately "difficult" or "obstinate". I'm
> being neither (OK, my wife
> would probably agree with the "obstinate" part), I
> just want a reasonable (logical, supported by data)
> answer to the questions that led me to conclude
> that thimerosal was not a likely cause of autism."