[ RadSafe ] Cohen's radon results differently

Mon Sep 19 18:20:51 CDT 2011

Another confounder, I would expect, is the movement of people.  For
example, my in-laws moved to a retirement home near us, about two years
before my mother-in-law died (not of cancer).  Any statistics pegged to
the county in which she died would introduce error into any study other
than one about end-of-life care, as the conditions in this county have
nothing to do with here long term health.  I would estimate that well
over half of the people at this large retirement facility are from out
of the county, and not a few from out of the state.  This effect has to
be even greater for places like Florida.  

The unlikely political bedfellows of Hilary Clinton and Newt Gingrich
have teamed up to support a national health records program (though
neither has spoken much about it recently).  The cost savings, both in
lives and in money, would be substantial, but I see even greater
possibilities in terms of being able to get MUCH better data for studies
such as this.  Imagine if instead of estimates of smoking prevalence you
could CONTROL for smoking habits of the case and control cohorts.  

There are people who contend that such a system is too much of an
intrusion into privacy, and that the couple tens of thousands of people
who die each year due to incomplete or inaccessible medical records is a
fair price to pay.  While I don't think they are right, I think they
will probably win until the Facebook generation takes the lead. 

-----Original Message-----
From: radsafe-bounces at health.phys.iit.edu
[mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of Bernard L.
Cohen
Sent: Monday, September 19, 2011 3:55 PM
To: Chris Hofmeyr
Cc: radsafe at agni.phys.iit.edu; WesVanPelt at verizon.net
Subject: Re: [ RadSafe ] Cohen's radon results differently

To do anything, I would need some credible source of smoking prevalence 
data. I tried several and they did not change my results. Please suggest

an alternative.

On 9/18/2011 3:31 PM, Chris Hofmeyr wrote:
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> Radsafers,
> On 19th June Howard Long challenged my reminder that in Cohen's
US-wide study
> of domestic radon and lung cancer, there was, on average, a negative
> correlation between Cohen's smoking prevalence and the average county
radon
> concentration. Howard wanted numbers.
> On 20th June prof Cohen invited further discussion of his work.  Then
away on
> an extended stay, I told dr Long that I will have a look when I get
back home.
>
>
> B Cohen and Wes van Pelt had kindly made their data available in
spreadsheet
> form almost a decade (and a few computers)ago. At the time and later I
did
> numerous plots and wrote some notes, which I now found on an archive
disk.
>
>
> I put some of it together in a .pdf file of about 1.5MB (attached);
please
> excuse some repetition in the text. If the attachment does not survive
Radsafe,
> then please request directly from me at webmail address below.
>
> Some background for the younger crowd:
>
> Cohen set out to study lung cancer rates as a function of county
average
> domestic radon concentration (ARC)in 1601 US counties. His null
hypothesis was
> presumably to justify LNT (Linear No-Threshold model of
carcinogenesis).
>
>
> However, fate stacked the cards in that smoking prevalence, as
determined by
> him, was to a degree anti-correlated with average county radon. Due to
the
> carcinogenic strength of smoking, the raw data naturally reflected an
> anti-correlation with radon concentration.
>   
> This meant that the lung cancer data would have to be carefully
corrected to
> extract a 'real' correlation, which Cohen probably only realized when
he was
>
> analyzing the data. Cohen tried more than one avenue to assess smoking
prevalence
> and he was obviously reasonably satisfied with his final choice,
although his
> correction strangely left the anti-correlation practically unchanged.
>
>   
> Having investigated lung cancer (LC) - Cohen's and Van Pelt's data -
also in
> relation to elevation and county population size, I am practically
forced to
> the conclusion that there appears to be a strong smoking residual even
after
>
> the correction. LC shows an even stronger anti-correlation with
altitude below
> 1260ft than with radon (ARC) below about 3pCi/L,yet (LC) proves
independence of both.
>   
> Cohen tested several hundred possible confounders, but very few
managed to turn the LC
>
> correlation with Average radon positive.
> I would respectfully ask prof Cohen: SUPPOSE the smoking correction
was
> insufficient and left an implicit smoking component in the LC data?
>
> In the notes I explain how one can use a plotting trick on Cohen's
data to
> evaluate LC dependence (or rather independence) on ARC even without a
smoking
>
> correction to the LC data - and consequently dispose of LNT.
>
> Regards
> chris.hofmeyr at webmail.co.za  <mailto:chris.hofmeyr at webmail.co.za>

-- 
Bernard L. Cohen
Physics Dept., University of Pittsburgh
Pittsburgh, PA 15260
Tel: (412)624-9245  Fax: (412)624-9163
e-mail: blc at pitt.edu  web site: http://www.phyast.pitt.edu/~blc

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