Re: Puskin article

[BERNARD L COHEN <blc+@pitt.edu>]

> > After reading the Radsafe Archives, I was wondering if Dr.Cohen sent out

> either the $1,000.00 or $2,500 reward for this in response to this paper

> that more than meets the criteria (as can be found in the archives) for his

> reward?

> >

> > Health Phys 2003 Apr;84(4):526-32 ..

> >

> > Smoking as a confounder in ecologic correlations of cancer mortality rates

> with average county radon levels.

> >

> > Puskin JS.



My response to the Puskin paper is posted as item #15 on my web

site at    www.phyast.pitt.edu/~blc    The paper was submitted to

Health Physics. The abstract follows:



In studies of U.S. counties, we have reported that regression of lung

cancer rates, m, with or without correction for smoking prevalence, S, on

average radon exposure, r, gives a strong negative dependence (less cancer

for more radon), a very large discrepancy with the strong positive

dependence predicted by linear-no threshold theory. In a recent paper,

Puskin reported results of simple regressions on r, and of multiple

regressions on r and S, for rates of lung cancer and other smoking related

cancers. He observed that the dependence on r is strong and negative in

simple regressions, and not much less negative in multiple regressions,

for all cases. He contends that a negative dependence on radon exposure

for the other smoking related cancers is impossible, and concludes that

his observation can only be caused by large errors in our S-values,

missing a strong negative S-r correlation. He claims that this invalidates

our results for lung cancer. In this paper, we examine Puskin's proposed

explanation quantitatively and find that even a perfect negative S-r

correlation does not resolve the problem, regardless of the width or shape

of the distribution of S-values assumed. We then review the three

independent sources of our S-values, and show that they each give

essentially the same results both in our studies and in Puskin's work, and

in analogous studies of cancer rates in states (rather than in counties)

where S-values have less uncertainty. Alternative explanations for the

Puskin observation, which do not conflict with our previous conclusions,

are then offered.