Re: Reward offer-Clarification

[Bernard L Cohen <blc+@pitt.edu>]

	As a clarification of my reward offer on this listserv, dated
February 29, my understanding of "potential explanation" is something that
can be paraphrased as follows: "I suggest that the observation that lung
cancer rates in U.S. counties *decreases* rapidly (7-8 % per pCi/L) with
increasing radon exposure in those counties, in sharp contrast to the
prediction of linear-no threshold theory that lung cancer rates should
*increase* rapidly (7+ % per pCi/L), might be explained by X-Y-Z".
	Some examples of X-Y-Z that would receive this reward if it were
retroactive (which it is not) are:
	1. Lubin's suggestion (Health Physics 75:4-10;1998) that
individuals who smoke may have lower average radon exposures than
individuals who do not smoke
	2. The suggestions by Smith, Field, and Lynch (Health Physics
75:11-17;1998)that exposures outside the home were ignored, that % of time
spent inside the home may vary, and that measurements were made of radon
gas whereas lung cancer is caused by radon progeny.
	3. Archer's suggestion (Health Physics 75:652-653;1998) that total
county population may be an important confounding factor because it is
strongly correlated with both radon levels and lung cancer rates, for
unrelated reasons.
	4. Goldsmith's suggestions (Health Physics 76:553-557;1999) that
the radon exposure data may not be reliable, and that population density
may be an important confounding factor.
	5. The BEIR-VI suggestion that no account was taken of variations
in the intensity of smoking, as 1 pack/day vs 2 pack/day.
	6. Doll's suggestion (J. Radiol. Prot. 19:65;1999) that no account
was taken of the proportion of ex-smokers who have stopped for different
periods, the proportion of smokers who smoked cigarettes, cigars, and
pipes, and the age at which smoking began.

	All of the above would have received the rewards. An example of
X-Y-Z that I would not interpret as an "explanation' is that the
methodology was erroneous; that is too general. If the methodology was
erroneous, it should not be difficult to suggest a specific potential
explanation that might be overlooked or treated improperly by that
erroneous methodology.

	Incidently, I believe that my published analyses of suggestions
1-6 above showed that these explanations were completely implausible.
Others can judge whether or not they agree, but that is irrelevant to the
reward issue. I just want opportunities to analyze suggested explanations
of our discrepancy, and am willing to pay for such opportunities. I
believe that it is only by accumulating suggestions and their analyses
that the issue of validity of my test of the linear-no threshold theory
can be resolved. 


Bernard L. Cohen
Physics Dept.
University of Pittsburgh
Pittsburgh, PA 15260
Tel: (412)624-9245
Fax: (412)624-9163
e-mail: blc+@pitt.edu


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