Re: Absence of Evidence II -Reply

[Fritz Seiler <faseiler@nmia.com>]

Charles Willis wrote:

> Fritz,
>
> I cannot quarrel with the thrust of your argument, but I have a problem with your
> ready acceptance of "zero dose equals zero effect."  This sort of relationship seems
> almost self-evident in physics but not in biology.

Dear Charlie,

As Joe is on vacation, I will answer for both of us and assume the corresponding
responsibility.

Due to the length of our Comments, we had to be somewhat short on explanations.  This is
probably why you overlooked the tiny qualifier "excess"  added to the term "risk", and at
zero agent dose the excess risk is zero by definition.  There is thus nothing out of the
extraordinary about it.  Actually, any dose d can serve as a starting point for defining
an excess risk.  It is a simple function for the linear model only, but that is another
question.

As far as the rest of your comments are concerned, I am in complete agreement, and
enjoyed reading them  Just one question: what is a good reference for your Arndt-Schulz
law?  Casarett & Doull does not refer to it, but it gives an earlier reference in the
form of the writings of my fellow countryman Paracelsus, who said a lot more than just
"dosis venenum facit" (the dose makes the poison), all of it along the lines of the law
you cite.

Best regards

Fritz


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