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Re: Field's comments on Cohen's Observation
Let me rephrase my previous question: What difference will any of this make for the
practice of health physics?
I find it difficult to accept the implied contention that ICRP, NCRP, regulators, the
public, etc. will suddenly agree to abolish ALARA on the basis of a tenuous epi.
study that no one outside of a group group understands, much less accepts. Look at
how "Below Regulatory Concern" crashed and burned.
The opinions expressed are strictly mine.
It's not about dose, it's about trust.
Curies forever.
Bill Lipton
liptonw@dteenergy.com
epirad@mchsi.com wrote:
> Jim,
>
> Just for the record, what conclusion would that be?
>
> Bill Field
> >
> > Dr. Bill Field wrote:
> > -----Original Message-----
> > From: epirad@mchsi.com [mailto:epirad@mchsi.com]
> > Sent: Monday, June 16, 2003 9:06 AM
> > To: BERNARD L COHEN
> > Cc: radsafe@list.vanderbilt.edu
> > Subject: Re: Cohen's Observation
> >
> >
> > Dr. Cohen,
> >
> > <snip>
> >
> > The reason I enter this debate is not about ego, but rather because so many
> > people including knowledgeable HPs and Physicists misinterpret your findings
> > to indicate prolonged residential radon exposure does not cause lung cancer
> > (eventhough the vast majority of case-control studies indicate it does). You
> > have stated yourself ecologic studies can not assess risk. This needs to be
> > stated by you more often. While ecologic studies can not assess causality,
> > analytic epidemiology studies (such as case-control studies) do have the
> > ability to establish causality.
> >
> > If you would have found a positive ecologic association between radon and lung
> > cancer and used that to state this proves the LNT is valid, I would be just a
> > fervent in my opposition in you using it to test the LNT because of the
> > limitations of the ecologic design. This debate has not been about the
> > validity of the LNT, this debate has been about the limitations of ecologic
> > studies. You state the limitations inherent in ecologic studies do not exist
> > if you use an ecologic design to test the LNT, no knowledgeable epidemiologist
> > would agree with such a contention.
> >
> > The validity of the LNT should be tested, but not by such a weak tool as an
> > ecologic study.
> >
> > I am sure there are many other areas we do agree on, but the proper use of an
> > ecologic study is not one of them.
> >
> > Regards, Bill Field
> >
> > ====================
> >
> > Dr. Cohen has always clearly stated the conclusion that he believes his analysis
> > of the county data supports and should not be responsible for
> > mis-interpretations or mis-representation of those conclusions.
> >
> > From LNT, it follows as the night the day that radiologically-induced cancer
> > incidence (and cancer mortality, given reasonably uniform standards of
> > treatment) is a linear function of person-rem exposure. As such, an ecologic
> > study is adequate to test the LNT, assuming dependence and confounding issues
> > can be handled.
> >
> > To even suggest that Dr. Cohen might have tried to prove the validity of LNT
> > using his or any other data set misunderstands the nature of the scientific
> > method, at least in the Popperian formulation. Nature whispers yes and shouts
> > NO. An experiment whose results conform to the predictions of a theory does not
> > "prove" validity of the theory. It may gives us a warmer feeling about the
> > theory. Many confirmatory experiments may lead us to believe to a high level of
> > confidence that the theory is true, but they do not "prove" its truth. "Proof"
> > is a concept that lives in Mathematics not in Science.
> >
> > On the other hand, a theory may make predictions that are falsifiable, in the
> > sense that we can design and perform an experiment whose outcome is capable of
> > contradicting the predictions of the theory. If we were perform the experiment
> > and the results indeed contradict the predictions of the theory, then we need a
> > new theory. To many, including me, Cohen's dataset and his analysis look very
> > much like such an experiment.
> >
> > Finally, "knowledgeable epidemiologists" believe a number of weird things, case
> > in point being Rothman's assertion a while back that epidemiologists didn't need
> > to bother with the Universal Null Hypothesis in their consideration of whether
> > their data said something meaningful or was simply a reflection of random
> > variation.
> >
> > Best regards.
> >
> > Jim Dukelow
> > Pacific Northwest National Laboratory
> > Richland, WA
> > jim.dukelow@pnl.gov
> >
> > These comments are mine and have not been reviewed and/or approved by my
> > management or by the U.S. Department of Energy.
> >
> >
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