Re: Re: Lung Cancer and Radon

[FIELDRW@aol.com]

In a message dated 11/13/98, 10:09:45 AM, Dr. Raabe  writes:

With regard to Bernie Cohen's analysis of the radon/lung-cancer
relationships in the U.S. ecological data, the ecological fallacy does not
apply (as Cohen has emphasized) if LNT is true. This is because LNT
predicts that the risk is the same no matter how the dose is distributed.
Hence, Cohen's analysis shows that the LNT does not work for radon
exposures in the home. The only possible way to attack this finding is to
suggest that it is the result of some mysterious unknown cross-level
confounding factor that we have yet to discover.

Prof. Otto G. Raabe, Ph.D., CHP
-----------------------------------



In our HPJ forum article and rejoinder (Volume 75-1,1998), we showed that Dr.
Cohen was using the wrong formula to test the LNT.

In addition, the major confounding factor that Dr. Cohen would and should have
is confounding due to smoking, because most lung cancers are caused by
smoking.  Was Dr. Cohen able to adequately adjust for smoking?  A regression
of his smoking rates on lung cancer showed he was only able to account for
23.7% of the cancers among females and 34.5% among males.  That leaves quite a
few to be accounted for.  Also, if you regress Dr. Cohen's smoking rates on
his radon data you will find a huge negative correlation (p<0.00001).  If you
do not adequately control for smoking you will be left with the neagative
association Dr. Cohen finds.  

Dr. Cohen uses numerous measures to try to adjust for smoking, but they all
fall short because ot the poor quality of the smoking data.

I would urge all radsafers to read the Forum paper, Dr. Cohen's response and
the rejoinder in the HPJ.  Perhaps this topic is better left to letters-to-
the-editor.  I am sure Melissa would approve of that.  If you do not get the
journal, please let me know and I will send a reprint of the forum article.

Regards, Bill Field

R. William Field, Ph.D.
Department of Preventive Medicine
University of Iowa
Iowa City, Iowa 52242

bill-field@uiowa.edu
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