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Re: A question of statistical significance vs operational significance



Bill, I read your referenced debate with Becker. I cannot offhand suggest a nice

neat empirical bundle defining some uncomplicated relationship such as LC as a

function of radon exposure. Absent this dream dissertation research that would

cause every PhD candidate to salivate profusely, I am less concerned with

accounting for your particular findings or with accounting for Cohen's findings in

terms of your experimental hypotheses rather than his; I am impressed by: 1. the

increasingly obvious (and embarrassing) fact that there is much that we still do

not know about smoking, and 2. radon is such a small or even possibly "negative

threat" (can we have negative threats?) to human health that available resources

would be more gainfully employed along other avenues. I mean no personal offense

to you at all, but I think EPA and related govt. efforts have really gone astray.



My impressions are very much influenced by the scientific evidence (which by now

exceeds the anecdotal level) cited by Ted Rockwell, Tom Mohaupt, and others

showing beneficial health effects of exposure to low level radiation. Perhaps

there remains to be found some peculiar characteristic of radiation by radon in

contrast with other sources of radiation. But radon is having one hard time living

up to its villain role.



However, I see nothing convincing yet in your data taken alone to imply a health

threat from radon -- totally aside from Cohen's work. It just seems to me that

your studies are attempting to isolate a tiny, tenuous experimental effect that

just cannot rise above the error variance. It is this conclusion which for me

suggested initially the contrast between statistical significance vs operational

significance.  If anything, I think the data are pushing us more and more in the

direction of viewing radon as a likely cancer preventative. I see your efforts as

struggling to set your teeth into an extremely elusive target. I admire your

tenacity, but I think your data increasingly are unable to pull the load.

Sincerely,

Maury

===========================================

epirad@mchsi.com wrote:



> Maury,

> You stated,

> " When thinking about the increasing weight of

> evidence favoring beneficial health effects from

> exposure to low level radiation (such as household

> radon), I cannot bring myself to get very concerned about

> the EPA radon campaign."

>

> Maury, other than Dr. Cohen's data, which he himself

> says does not suggest hormesis (to do so he says would

> make his findings subject to the ecologic fallacy), can

> you point me to any well designed study that

> demonstrates residential radon exposure decreases lung

> cancer risk?

>

> Please see this reference for my view of this issue:

> http://www.ntp.org.uk/951-TUD.pdf

>

> Bill Field

> >

> >

> > Bill, thanks for taking the trouble to refer me to relevant data. My

> > impressions, however, are that you folks are suggesting with an

> > epidemiological risk factor of 0.5, that out of an annual total lung

> > cancer

> > incidence of 157,400 cases, 18,600 or about 12% are attributable to

> > radon. I

> > don't believe those radon cases could hope to be distinguished from the

> > noise

> > or error variance.  When thinking about the increasing weight of

> > evidence

> > favoring beneficial health effects from exposure to low level radiation

> > (such

> > as household radon), I cannot bring myself to get very concerned about

> > the EPA

> > radon campaign -- except for some of my darker suspicions which already

> > have

> > been well-fed over the years by the performance of EPA. I just cannot

> > view

> > radon as a threat and I suspect it might even be beneficial to us.

> > Perhaps my

> > ignorance, but time will tell after I'm long gone.

> >

> > Thanks again for your response to me.

> > Sincerely,

> > Maury                   maury@webtexas.com

> > ================================

> > epirad@mchsi.com wrote:

> >

> > > Maury,

> > >

> > > Our direct observations

> > > http://www.cheec.uiowa.edu/misc/radon.html are in

> > > agreement with the BEIR VI

> > > (http://www.epa.gov/iaq/radon/beirvi1.html)projections

> > > which estimate that approximately 18,600 lung cancer

> > > deaths each year in the United States are associated

> > > with prolonged radon progeny exposure.

> > >

> > > Bill Field

> > > > Bill,

> > > >

> > > > Would you select an objective, reliable measure of the impact of

> > > > cancer on human health, e.g., mortality, morbidity, longevity, etc. and

> > > > tell me what that observation is today in perhaps the US, or the world,

> > > > or Iowa, or whatever? Then, if we could suddenly cause all radon and its

> > > >

> > > > progeny to disappear completely from the earth while all other

> > > > conditions remain unchanged, what do you see in any hard data, or

> > > > believe would be the observed effect or change in that selected cancer

> > > > measurement in, say, 20 years or so?

> > > > Cheers,

> > > > Maury Siskel           maury@webtexas.com

> >

> > ------------------

> > It is the soldier, not the campus organizer, who has given us the

> > freedom to demonstrate.                       Charles M. Province

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> >



--

It is the soldier, not the campus organizer, who has given us the

freedom to demonstrate.                       Charles M. Province





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