RE: Absence of Proof...

[Falo Gerald A <Gerald.Falo@APG.AMEDD.ARMY.MIL>]

Well, as long as this has returned, I have some questions and or comments.
I have tried to follow this thread as best I can.  Forgive me if I am
rehashing things already discussed.


1. Dr. Seiler states essentially that the scientific method works by using
experimental results to compare with model predictions.  I agree completely
with this statement.  But it seems to me that despite the amazing and
thorough work that Dr. Cohen has done it is not an experiment.  I don't know
if this is a philosophical or minor point, but to me an experiment implies
an active design to acquire data.  Dr. Cohen's work is more observational.  

In terms of the scientific method, I would use Dr. Cohen's data as strong
observational evidence that something is awry.  Then, the next step would be
to design an experiment to explicitly test a model.  I understand that I may
not understand the depth of Dr. Cohen's analyses.  From what I've seen, his
work is exceeding well thought out and deep.

The scientific method came into being well before the discovery/invention of
statistical analysis and was

		1. Observation
		2. Form a hypothesis
		3. Acquire data to test the hypothesis.

2. I think for certain, perhaps over simplified examples, it is possible to
prove things in science.  For example, I see that in my family and in my
neighbors all the married men wear wedding bands.  I formulate a hypothesis:
All married men wear wedding rings.  Now, I go out and collect data on that
hypothesis.  I find that many married men do not wear wedding bands;
therefore, my hypothesis is proven false.  There is no uncertainty because
of the absolute nature of the hypothesis.  Is this type of *experiment*
science?  I think it is, albeit a primitive form.

3. Dr. Seiler states, "...As long as we cannot measure a quantity above the
ever present noise, its value can assume just about any shape as long as the
effects are compatible with the errors of the zero effect."  This is not
quite clear to me. But regardless, this statement implicitly assumes that
the measurement process is appropriate for the effect desired.  For example,
if I wanted to know the number of red and white cars in a given parking lot,
I had better make sure that whoever is doing the counting is not colorblind.
Otherwise, zero red and white cars will be reported regardless of the true
number present.

4. One question that I have had is "Can Dr. Cohen's results, if
demonstrating non-LNT for radon, be applied across the board for all
radiation exposures?"  My first instinct is to say no.  Within the
constraints under which Dr. Cohen's data were collected, it seems that radon
exposure and lung cancer do not follow the LNT.  That seems to me that is
the only conclusion that can be drawn from Dr. Cohen's data. It certainly
doesn't seem scientific to conclude that based on Dr. Cohen's study that
every cancer that may be radiogenic does not follow a LNT-type model.

5. It still seems to me that the LNT proponents and supporters of other
models often talk past each other.  There is a difference between science
and policy and the bridge between the two is still under construction.
Sure, the LNT for all radiation is shaky at best (I would tend to agree with
this.), but for setting regulations, which is as much a political/social
process a it is science, just saying the LNT is unscientific is not helpful
to a regulating organization.

6. In terms of radiation protection policy, what needs to be done? Can we
say that because we can't see and effects in humans below about 20 rem or
so, that for policy we will assume that there are none?  I doubt that this
would ever happen given the social constraints of policy making.


Well, I'll quit now.  I reserve the right to be wrong and in no way wish to
impugn the motives and scientific rigor of anyone.  I just wanted to throw
out a couple of points that I have wondered about.

Thanks for your patience,

Jerry Falo, Ph.D., CHP
HMJ Professional Associate
USACHPPM
Medical Health Physics Program
gerald.falo@apg.amedd.army.mil

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