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Re: Radon's linear dependency



John,
 
In a private email to you I wrote the response (below) to a different email you sent directly to me so it may be a bit difficult for others to track.  In your previous email I thought you were referring to the fact that the best use of ecologic studies is to form hypotheses, not test them.  Nonetheless, my post was a response to Dr. Cohen regarding BEIR which showed that the relative risks based on cumulative radon exposure are linear, but with a dependency on age, pack-year rate of smoking, smoking duration, etc.  Dr. Cohen is using an ecologic study to test the validity of the LNT.  My previous point was to test the LNT or LNTassumption by using collective dose assumptions does not add up to me.  The reason it does not add up is the association between radon exposure and risk will not be linear using his ecologic data unless age, pack-year rate - smoking intensity, smoking duration, etc. are considered, which is impossible using ecologic data.  So if you do not include these factors as he does not, he is not testing the LNT.  When he states the LNT fails, I consider it more a failure of his study design to accommodate the non linear dependencies of pack year rate, smoking duration, etc.
 
John, again, my goal is not to convince anyone, but to state why I personally have questions with his ecologic analyses. I do think this type of study design to test the LNT is fatally flawed. I do think more work is needed that will either verify the validity for certain types of radiation or disprove the validity of the LNT, however I do not think the examination should take the form of an ecologic study.
 
Bill 

 
----- Original Message -----
Sent: Saturday, February 16, 2002 6:59 PM
Subject: Re: Radon's linear dependency

In a message dated 2/16/2002 3:17:07 PM Eastern Standard Time, bill-field@uiowa.edu writes:


But,

Bernie says he is testing the LNT theory, not an hypothesis, right?  

Just so I am clear, what do you think is the proof that it does not?

Maybe, I am missing your point.

Bill


Bernie says he is testing the LNT theory, when he means that the theory is "a hypothesis assumed for the sake of arguement or investigation or an unproved assumption" (from my New Collegiate Dictionary).  What I believe we should be arguing is that the LNT theory is not in fact a theory meaning "a plausible or scientifically acceptable general principle or body of principles offered to explain phenomena" (ibid).  I do not see a phenomena that needs explaining.  What I see is a conservative assumption that is having huge and expensive impact on the body politic and on the urgent need for safe electricity for the world that has minimal environmental impact.  The assumption of the linear no-threshold theory is really a hypothesis, not a proven theory yet.  It may be a long time before we know enough to prove this as theory.  The LNT hypothesis is according to my dictionary: "a : an assumption tor concession made for the sake of arguement or b :! an interpretation of a practical situation or condition taken as the ground for action."  This to me seems to be the case for LNT, and until we can show definitely that there are predictable excess cancers or other effects that actually reduce mortality, the LNT remains a hypothesis, not a theory.

John Andrews
Knoxville, Tennessee