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Re: Cohen's Refutation of LNT
It is still a common misconception that should be cleared up, regardless of
who posted it or where it was posted.
----- Original Message -----
From: "Rad health" <healthrad@hotmail.com>
To: <info@eic.nu>; <bill-field@uiowa.edu>
Cc: <radsafe@list.vanderbilt.edu>
Sent: Sunday, February 10, 2002 4:49 PM
Subject: Re: Cohen's Refutation of LNT
> Did I post that to Radsafe?
>
> If you check, I have not posted anything to Radsafe for at least a week.
>
>
> >From: Kai Kaletsch <info@eic.nu>
> >To: Rad health <healthrad@hotmail.com>, bill-field@uiowa.edu
> >CC: radsafe@list.vanderbilt.edu
> >Subject: Re: Cohen's Refutation of LNT
> >Date: Sun, 10 Feb 2002 16:39:40 -0600
> >
> >You said wrt Colditz and Cohen's data:
> > > He would say the ecologic study was good to form hypotheses, but the
> > > hypotheses have been proven wrong by the more rigorous case-control
> >studies.
> >
> >My question was: What formal hypothesis was ever formulated from Cohen's
> >(or
> >EPA) data and what case-control study has tested (never mind proved
wrong)
> >such a hypothesis?
> >
> >Kai
> >
> >----- Original Message -----
> >From: "Rad health" <healthrad@hotmail.com>
> >To: <info@eic.nu>; <bill-field@uiowa.edu>
> >Cc: <radsafe@list.vanderbilt.edu>
> >Sent: Sunday, February 10, 2002 4:14 PM
> >Subject: Re: Cohen's Refutation of LNT
> >
> >
> > > An hypothesis does not have to be a risk model. Most of the
residential
> > > radon studies' hypotheses were that there is increased lung cancer
with
> > > increased radon exposure. I don't think anyone set out in their
> >hypotheses
> > > whether to test the shape of the dose response curve. Maybe the
pooling
> > > studies are doing that?
> > >
> > > The Iowa study showed how a case-control study can show different
> >results
> > > than an ecologic study. This has been shown by others also.
> > >
> > > I think the hypotheses the Iowa Study choose to explore, since their
> > > experimental objectives included smokers, was does radon have a
> > > statistically significant dose response in those people who have
> >developed
> > > lung cancer. I think Dr. Field already said they were going to look
at
> >the
> > > non smokers in the pooled analyses.
> > >
> > > >From: Kai Kaletsch <info@eic.nu>
> > > >To: field <bill-field@uiowa.edu>, Rad health <healthrad@HOTMAIL.COM>
> > > >CC: radsafe@list.vanderbilt.edu
> > > >Subject: Re: Cohen's Refutation of LNT
> > > >Date: Sun, 10 Feb 2002 13:54:28 -0600
> > > >
> > > >Sorry, what I meant to ask was if anyone had formulated an individual
> >risk
> > > >model (hypothesis) based on the US data (Cohen's or EPA ...)
> > > >
> > > >Thanks for the reference below. For a specific question about that
> >paper:
> > > >
> > > >What was the hypothesis that was generated from the fact that "Within
> >low
> > > >smoking
> > > > counties, rates for all lung cancer and small cell carcinoma were
> > > > significantly lower (p < 0.05) in the high radon counties relative
to
> >the
> > > > medium and low radon counties." and how was it tested in the later
> >Iowa
> > > >study?
> > > >
> > > >An obvious hypothesis (but not the only possible one) would be: "In
low
> > > >concentrations, radon can prevent the occurrence of lung cancers in
> > > >non-smokers."
> > > >
> > > >To test this hypothesis with a case control study, you would limit
the
> > > >study
> > > >to non-smokers, because your hypothesis only deals with non-smokers.
> >You
> > > >would also have to choose your exposure categories so that an
increased
> > > >risk
> > > >in "low" exposed individuals could be detected. That would probably
> >mean
> > > >limiting your study to low radon, low smoking counties. (After all,
you
> >are
> > > >trying to figure out what is killing the people in these counties.)
> > > >
> > > >The obvious problem with a study like this is the small sample size.
> > > >However, including individuals or populations (e.g. smokers) that are
> >not
> > > >relevant to your hypothesis actually makes the statistics worse.
> > > >
> > > >Science should go like this:
> > > >
> > > >1. You make an observation. (via ecological study or whatever.)
> > > >2. You come up with a formal, preferably quantitative, hypothesis
to
> > > >explain your observation.
> > > >3. You crunch the numbers to ensure that your hypothesis could
> >actually
> > > >explain your observation. If it can't, go back to step 2.
> > > >4. You design an experiment (case-control study or whatever) to
test
> > > >your
> > > >hypothesis.
> > > >5. You clearly state the hypothesis to be tested and how the
> >particular
> > > >experiment will confirm or refute the hypothesis.
> > > >6. You perform the experiment and present the results.
> > > >7. You show how the results of the experiment either confirm or
> >refute
> > > >the hypothesis.
> > > >8. If your experiment refutes the hypothesis, go back to step 2.
> > > >
> > > >All I can see are steps 1 and 6.
> > > >
> > > >Regards,
> > > >Kai
> > > >
> > > >----- Original Message -----
> > > >From: "field" <bill-field@uiowa.edu>
> > > >To: "Kai Kaletsch" <info@eic.nu>; "Rad health"
<healthrad@HOTMAIL.COM>
> > > >Cc: <radsafe@list.vanderbilt.edu>
> > > >Sent: Sunday, February 10, 2002 12:10 PM
> > > >Subject: Re: Cohen's Refutation of LNT
> > > >
> > > >
> > > > > Kai,
> > > > >
> > > > > We published an ecologic study very early on before we followed up
> >with
> > > >a
> > > > > case control study.
> > > > >
> > > > > : Health Phys 1994 Mar;66(3):263-9 Related Articles, Books,
LinkOut
> > > > >
> > > > >
> > > > > Residential radon exposure and lung cancer: evidence of an urban
> >factor
> > > >in
> > > > > Iowa.
> > > > >
> > > > > Neuberger JS, Lynch CF, Kross BC, Field RW, Woolson RF.
> > > > >
> > > > > Department of Preventive Medicine, University of Kansas School of
> > > >Medicine,
> > > > > Kansas City 66160-7313.
> > > > >
> > > > > An ecological study of lung cancer, cigarette smoking, and radon
> > > >exposure
> > > > > was conducted in 20 Iowa counties. County-based lung cancer
> >incidence
> > > >data
> > > > > for white female residents of Iowa were stratified according to
> >radon
> > > >level
> > > > > and smoking status. Cancer incidence data for the period 1973-1990
> >were
> > > > > obtained from the State Health Registry of Iowa. Smoking level was
> > > > > determined from a randomly mailed survey. Radon level was
determined
> > > > > according to an EPA supported charcoal canister survey. Within low
> > > >smoking
> > > > > counties, rates for all lung cancer and small cell carcinoma were
> > > > > significantly lower (p < 0.05) in the high radon counties relative
> >to
> > > >the
> > > > > medium and low radon counties. However, within high smoking
> >counties,
> > > >rates
> > > > > for all lung cancer, adenocarcinoma, and small cell carcinoma were
> > > > > significantly higher (p < 0.05) in the high radon counties
relative
> >to
> > > >the
> > > > > low radon counties. Variations in socioeconomic data for these
> >counties,
> > > > > available through the 1980 and 1990 census, did not explain these
> > > >results.
> > > > > Lung cancer rates also were significantly increased in urban
> >counties
> > > >even
> > > > > after holding smoking status constant. Multivariate analyses
> >revealed
> > > > > significant interactions between smoking, urbanization, radon
> >levels,
> > > >and
> > > > > lung cancer. The results of this hypothesis generating study will
be
> > > >tested
> > > > > in a case/control study now ongoing in Iowa. Analysis will need to
> > > >include
> > > > > separate evaluations by smoking status, radon level, and residence
> >in
> > > >urban
> > > > > or rural areas for the major morphologic types of lung cancer.
> > > > >
> > > > > Regards, Bill
> > > > >
> > > > > ----- Original Message -----
> > > > > From: Kai Kaletsch <info@eic.nu>
> > > > > To: Rad health <healthrad@HOTMAIL.COM>
> > > > > Cc: <radsafe@list.vanderbilt.edu>
> > > > > Sent: Sunday, February 10, 2002 10:51 AM
> > > > > Subject: Re: Cohen's Refutation of LNT
> > > > >
> > > > >
> > > > > > > He would say the ecologic study was good to form hypotheses,
but
> >the
> > > > > > > hypotheses have been proven wrong by the more rigorous
> >case-control
> > > > > > studies.
> > > > > >
> > > > > > Could anyone please provide a reference where a hypothesis has
> >ever
> > > >been
> > > > > > formed based on the ecological radon data? So far I have only
seen
> > > > > > regressions of the COUNTY risk. I am not aware of a single
> >INDIVIDUAL
> > > >risk
> > > > > > model that has been constructed to explain the county data.
> > > > > >
> > > > > > Could anyone please provide a reference where such a hypothesis
> >has
> > > >been
> > > > > > tested by a case control study. The studys I have seen simply
find
> > > >risk
> > > > > > coefficients for a linear model. Would anyone really hypothesise
a
> > > >linear
> > > > > > individual risk model by looking at the county data?
> > > > > >
> > > > > > Thanks,
> > > > > >
> > > > > > Kai
> > > > > >
> > > > > >
> > > > > >
> > >
> >
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