RE: Field's comments on Cohen's Observation

["Dukelow, James S Jr" <jim.dukelow@PNL.GOV>]

Bill,



I am sorry if you are offended that I provided the off-list context for the message you sent to the list, but I was similarly offended to have my positions un-represented and mis-represented by the list hearing only one side of the conversation.



In particular, I made some specific responses to your questions -- questions and comments that are repeated in your posting, as if I had never responded.



I prefer that the subscribers to RADSAFE be aware of my previously expressed arguments, while considering your comments.



Your posting, which was sent to me and to the list around noon on 6/18 is essentially identical to a message you sent to me around noon on 6/17, a message I had not had an opportunity to respond to, in what I considered our off-list discussion of the issues.



Your posting was not sent to the list "several days ago".



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.



-----Original Message-----

From:	epirad@mchsi.com [mailto:epirad@mchsi.com]

Sent:	Wed 6/18/2003 2:13 PM

To:	Dukelow, James S Jr

Cc:	BERNARD L COHEN; radsafe@list.vanderbilt.edu

Subject:	RE: Field's comments on Cohen's Observation



Jim, this post below was sent to the list a few days ago, your last message 

included off list messages.  



Bill



------------------------------



You stated that 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.



I have two brief comments,



First, radiologically induced lung cancer is not a linear function as per 

person-rem unless you can describe the population in pretty good detail. For 

example, there are many factors that modify the assumed linearity such as age, 

smoking, etc. 



 Secondly, you state that ASSUMING dependence and confounding issues can be 

handled, an ecologic study is adequate to test the LNT"



That is really the heart of the problem isn't it?  Dr. Cohen has not persuaded 

me or from what I can tell most informed epidemiologist and statisticians that 

he has indeed handled effect modifiers and confounders adequately.  Dr. Cohen 

has not addressed the within county joint distributions of even smoking and 

radon let alone all the other socioeconomic factors that are also co-

correlated with smoking. Because Dr. Cohen uses ecologic smoking information, 

he can not hope to correct for the problem I mentioned above regardless how 

many attempts he makes.  



I previously sent Dr. Cohen a possible methodology to address the within 

county joint distribution problems, but he indicated to me that he thought the 

methodology had little to do with his work.  Therefore, that created a real 

impasse between us and is why I asked his cooperation in selecting a 3rd party 

to weigh in on this issue (especially if he plans to find any potential NCRP 

opinion on this topic biased).  We are getting no where in these discussions 

on the list and in fact the discussions have obviously become irritating to 

some (for which I apologize in part).



Regards, Bill Field









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