[ RadSafe ] Cohen's radon results differently

[Bernard L. Cohen]

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.
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> 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.
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> 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.
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> Some background for the younger crowd:
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> 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).
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> 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.
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> 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
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> 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.
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> 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
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> 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.
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> Cohen tested several hundred possible confounders, but very few managed to turn the LC
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> 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?
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> 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
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> correction to the LC data - and consequently dispose of LNT.
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> 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