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Re: Cohen's Fallacy
Mr. Rad Health,
I didn't put a spin on the German or Swedish data. I merely pointed out
facts in the data that were not addressed elsewhere. I think those
observations are important when drawing conclusions.
Please bear in mind that I formerly worked as a respiratory therapy
technician. I've tried to help hundreds of lung cancer patients fight for
life. I know what a dreaded disease it is firsthand. I would relish the
idea that reducing radon levels will make 1000s to 10,000s of lung cancers
disappear. I must admit that I'm skeptical that reducing radon will have
any impact on cancer incidence. You and I have both read through the BEIR
reports and many of the epidemiological studies. I remain a "Doubting
Thomas". The studies are upstanding and show what they intend to show, but
they have yet to address my concerns and convince me that radon is even as
significant of concern as chemical carcinogens or secondhand smoke.
I believe my skepticism is well founded. I've addressed smoking in earlier
posts.
How do you explain that Iowa has one of the highest radon concentrations,
yet one of the lower incidences of lung cancer?
How do you explain that in all radon studies, most cases are exposed to the
lowest concentrations of radon? Nearly all cases have less than the EPA
actions level.
I've explored how the 4 pCi/L action level was developed and regard that
level as a "Glass Ceiling". I have little regard for studies that use ">148
Bq/m^3". I know that the Iowa study did not and I respect that. My major
concern with the Iowa study is smoking.
I have concerns with the retrospective radon detector (RRD) system. They
report a 20% increase in radon levels over track etch detectors. The RRD
results can very by 25% over a single pane of glass. Variability of RRD in
houses with smokers is significant. I like the ingenuity of RRD, but I
question the reliability of readings in houses with smokers because of the
Po-210 introduced by tobacco smoke. In such instances, I think that track
etch provides a more accurage reading than RRD because the particulates are
filtered out.
Radon is a statistical disease. The query "Where are all the dead bodies?"
is as pertinent today as it was 25 years ago. I want to know how the EPA
plans to demonstrate that the radon program has been and is effective in
reducing lung cancers. From BEIR VI, it appears that IF the radon
mitigation program were completely successful, there would be no detectable
decrease in lung cancer statistics. That bothers me. Since lung cancer from
radon is a statistical disease, statistics is the only way to show that the
program is effective.
My other concerns are of a nature that I will not post them on RadSafe.
I look forward to the composite etiology lung cancers in never smokers, as
you are. You and I have the same goal in mind. Reduce lung cancers. Even
though both you and I have read through much of the same material, ou
believe that the radon mitigation will satistically reduce the number of
lung cancers; I, however, am skeptical.
Tom
Rad health wrote:
>
> Mr. Mohaupt,
>
> They adjusted for smoking using a multi variate analyses, that is correct.
> I believe the sample size in the North American pooling will be sufficient
> to determine whether or not radon exposure to just never smokers is a risk
> or not. My guess is it may be a greater factor since there is no increased
> mucous secretions from the smoking to attenuate the alpha particles. The
> hypotheses the Iowa Study was testing was whether or not prolonged
> residential radon is a problem in females who have developed lung cancer and
> have lived in the same home for at least 20 years. Perhaps they can perform
> another study on never smokers down the road, but that was not the focus of
> their study. I can not convince you of the strenth of multivariate
> analyses, that is your personal view and I respect that. Most epidemiologist
> (other than Howard who calls himself an epidemiologist) would disagree.
> Plus the Iowa inverstigators performed tests for residual confounding and
> did not find any.
>
> The German study was positive regardless of the spin you put on it.
> Alavanja's study was not of just never smokers, but rather ex smokers and it
> lacked power.
>
> Don
>
> >From: Tom Mohaupt <tom.mohaupt@wright.edu>
> >To: Rad health <healthrad@hotmail.com>
> >CC: RuthWeiner@AOL.COM, muckerheide@MEDIAONE.NET,
> >radsafe@list.vanderbilt.edu
> >Subject: Re: Cohen's Fallacy
> >Date: Mon, 28 Jan 2002 15:36:04 -0500
> >
> >Mr. Rad Health,
> >Ruth suggests that cases with smoking be subtracted from the data. You say
> >that that this is what was done with the Iowa study, and I disagree. The
> >cases with smokers were not subtracted, but included in the evaluation.
> >
> >Secondly, you espouse the virtues of a multivariate regression to account
> >for smoking and I disagree that this is adequate for radon and lung cancer.
> >
> >For most cancers other than lung, smoking is not a direct insult to the
> >organ in question, i.e., smoking tends to be another confounding factor. In
> >lung cancer, smoking directly insults the lung. About 90% of the lung
> >cancers would go away if smoking were removed. Smoking deposits hot
> >particulates in the lung. It contains enumerable chemical carcinogins.
> >Smoking directly changes the physiology of the respiratory system, thus
> >hindering the lung from functioning properly. It also deposits a higher
> >dose from alpha particles than from radon. Theory suggests that the alpha
> >particles from radon induce lung cancer. The dose from smoking is much
> >greater than radon, but it is not accounted for in the population-based
> >radon studies. It's not a simple confounder and cannot be treated as such.
> >Also, many of the radon studies of never-smokers have been negative. If the
> >smoking model is correct, the results of studies including smokers and
> >never-smokers should agree. Since they don't, I question whether the
> >modeling for smoking is correct.
> >Tom
> >
> >Rad health wrote:
> > >
> > > Ruth's second points:
> > >
> >
> > >
> > > >6. Look at whatever relationship exists between radon exposure and the
> > > >remaining lung cancers (those that occurred in non-smokers). It is
> >also
> > > >necessary to look at the secondary smoke exposure in non-smokers, since
> > > >secondary smoke is also a pretty well extablished carcinogen.
> > >
> > > This ignores the interaction between smoking and radon. You get alpha
> > > exposure from both radon and tobacco.
> > > This part of what Field did and this is likely what will be done in a
> > > pooling.
> > > >
> > > >Maybe this is what Field et al did -- I will have to get their papers
> >and
> > > >see. But it seems to me that applying some kind of statistical
> >correction
> > > >for smoking that says, in effect, since the national risk of lung
> >cancer
> > > >from
> > > >smoking is x, and the national (or statewide) fraction of smokers is y,
> > > >then
> > > >x*y *observed lung cancers are attributable to smoking and the rest to
> > > >radon,
> > > >doesn't really cut it. All that would tell you is the fraction of
> >lung
> > > >cancers that MIGHT be attributed to smoking.
> > >
> > > Regarding a smoking correction - As posted before on this list by
> >others,
> > > this is the most powerful way to adjust for smoking.
> > >
> > > Quoting Hosmer and Lemeshow's authoritative book, "Applied Logistic
> > > Regression":
> > >
> > > "One generally considers a multivariate analysis for a more
> >comprehensive
> > > modeling of the data. One goal of such an analysis is to statistically
> > > adjust the estimated effects of each variable in the model for
> >differences
> > > in the DISTRIBUTION of and associations among the other independent
> > > variables. Applying this concept to a multivariate logistic regression
> > > model, we may surmise that each estimated coefficient provides an
> >estimate
> > > of the log odds [of lung cancer] adjusting for all other variables
> >[smoking]
> > > included in the model."
> > >
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> >
> >--
> >Thomas Mohaupt, M.S., CHP
> >University Radiation Safety Officer
> >
> >104 Health Sciences Bldg
> >Wright State University
> >Dayton, Ohio 45435
> >tom.mohaupt@wright.edu
> >(937) 775-2169
> >(937) 775-3761 (fax)
> >
> >"An investment in knowledge gains the best interest." Ben Franklin
>
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--
Thomas Mohaupt, M.S., CHP
University Radiation Safety Officer
104 Health Sciences Bldg
Wright State University
Dayton, Ohio 45435
tom.mohaupt@wright.edu
(937) 775-2169
(937) 775-3761 (fax)
"An investment in knowledge gains the best interest." Ben Franklin
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