Re: Cohen's ecologic studies

[Bernard L Cohen <blc+@pitt.edu>]

	My statement is all that I can prove by rigorous mathematics. If
others are willing to make further conclusions, I welcome their efforts.
But I feel that having my mathematically proven results accepted would be
a very large step forward, and I do not want to jeapordize the success of
that step by going beyond it.

Bernard L. Cohen
Physics Dept.
University of Pittsburgh
Pittsburgh, PA 15260
Tel: (412)624-9245
Fax: (412)624-9163
e-mail: blc+@pitt.edu


On Thu, 26 Feb 1998 JMUCKERHEIDE@delphi.com wrote:

> > On Tue, 24 Feb 1998, R. William Field wrote:
> > > 
> > > Dr. Cohen,
> > > 
> > > Do you think your ecologic studies have the power to assess the lung cancer
> > > risk/benefit posed by residential radon exposure?
> > > 
> > > Bill Field
> > 
> > My study is a test of the linear-no threshold theory (LNT) of radiation
> > induced cancer. It shows that LNT fails very badly in the low dose region
> > ((below 6 pCi/L), grossly over-estimating the cancer risk in that region.
> > It does not determine the risk vs dose to individuals beyond the above
> > statement. Interpreting our data directly as risk vs dose suffers from
> > "the ecological fallacy", but the above-stated conclusion does not.
> >
> > Bernard L. Cohen
> 
> Hi Bernie,
> 
> It is not clear to me what this means; what is the data "suffering" from?
> 
> It seems that "the ecological fallacy" correctly reflects a potential weakness 
> in results that may be introduced when there is a threshold (NOTE: the
> argument that the "ecological fallacy" applies preordains the existance of a
> threshold!)  In that case, the premise is that the dose data reflect a mean
> that fails to reflect that the effects data only comes from the higher dose
> population. It is easy to see how this works for a specific low-dose bin in a
> typical simple ecological study. It is not clear how that affects considering
> the results of your study when examining the actual data, including error
> bars, eg, for counties at 0.5 pCi/l vs those at 1.5 pCi/l, vs 4 pCi/l, and 6
> pCi/l. 
> 
> Further, while it is easy again to accept that the "ecological fallacy" does
> not allow that these results be accepted as the definitive dose-response
> relationship, it seems nothing more than 'politically correct' to deny that
> the data show actual lower lung cancer in the large populations at 4-6 pCi/l
> vs those at 0.5-1.5 pCi/l. How does the actual mathematical treatment of the
> effects of the "ecological fallacy" deny that there is clear evidence of lower 
> cancer considering the size of these populations and datasets? and considering 
> the numerous completely independent analyses of subsets of these populations
> such that multiple independent studies demonstrate confirmatory results? (How
> many more than 20 independent studies are needed to conclude that the result
> is not an anomaly?  :-) 
> 
> In addition, Drs. Gary Sandquist, Jay Kunze, Vern Rogers, and others took
> EPA's state level radon data, and the American Cancer Society lung cancer
> data, and showed that the lowest US radon area, the Pacific Northwest states,
> had a lung cancer rate at 390% (4 times) the BEIR IV prediction, and the
> highest US radon area, the Rocky Mountain states, had a lung cancer rate 14%
> (1/7th) the BEIR prediction. Of course, the study of radon in France showed
> the same, the women in the uranium mining areas of Germany showed the same,
> and on, with small areas like the Misasa Spa area of Japan and Yangjiang
> Province in China not showing statistical significance in lower lung cancer in 
> smaller populations, but there is also no increase as would be predicted by
> BEIR. 
> 
> [It should also be noted that the power of the statistics of even a small
> ecological study (of a million+ people) is much more powerful than any human
> case-control study. This is simply because the power of a case-control study
> using small populations relies entirely on knowing the dose (in medical
> experiments, usually thru injection or ingestion). In the case of radon
> case-control studies, residential measurements are not directly related to
> doses to individuals, since any individual in a "radon pool" will inhale a
> different dose, like in what side of the bed she sleep on, or where the
> washing machine is located, etc etc (eg, in the French uranium miners,
> individual dose monitors did not correlate well with area monitors, with 2
> persons in the same area getting different doses). Therefore residential
> measurements are a level around which residents have a distribution of doses;
> and the radon case-control study depends on averages in these data (perhaps
> excepting, eg, cases like the women with lung cancer in the smaller, more
> controlled residences/populations, with a full year of monitoring, in Shenyang 
> China, with a negative correlation). But the populations are so small that,
> unlike the ecological study, the averages have large errors. So the results of 
> individual studies are all over the map. They become essentially useless data
> vs the quality of the data in a good, and there aren't many, ecological study, 
> like Cohen's.] 
> 
> Regards, Jim Muckerheide
> muckerheide@mediaone.net
> jmuckerheide@delphi.com
> Radiation, Science, and Health
>