Re: Apparent anti-correlations between geographic radiation and cancer are no...

[Kai Kaletsch <eic@shaw.ca>]

From: "BERNARD L COHEN" <blc+@pitt.edu>

...

> The solution to this is my approach of studying lung cancer in

> U.S. Counties vs radon exposure. For starters, according to LNT about 10%

> of lung cancers are due to radon, so this is already a 10-fold advantage.

> More important, my study involves 1600 counties which allows very

> elaborate treatment of confounding factors. This treatment is reviewed in

> paper #7 on my web site,   www.phyast.pitt.edu/~blc



Have you ever treated terrestrial gamma radiation as a confounding factor in

your radon vs lung cancer studies? In other words: Is it possible that the

negative correlation you see between radon and lung cancer has nothing to do

with radon, but is rather an effect of gamma radiation or something else

that is related to radon by a physical mechanism?



There are 2 reasons for asking the question:



1) There are some people who are reasonably open minded when it comes to the

possibility of a protective effect of gamma radiation, but who loose it when

the discussion goes to alpha radiation.



2) While I usually disagree with the authors' conclusions (radon causes lots

of lung cancers) in the case-control studies, the data does not seem to

support a large protective effect of radon. (I would think that in case

control studies the variation in radon concentration is mainly determined by

building construction and ventilation. In an ecological study, the average

county radon concentration would be mainly influenced by the source term.)



BTW, just because the upper limit of the detrimental effect of background

radiation is about 1% of cancers (LNT) does not necessarily mean that the

potential beneficial effect is limited to 1%.



Best Regards,

Kai

http://www.eic.nu

http://www.gammawatch.com/



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