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Re: A question of statistical significance vs operational significance
Tom, You're looking at this too simplistically.
Landauer's ATDs performed very well. Look at the MO-II
findings that used ATDs versus glass-based measurements.
The findings are quite different. Also look at the
percent of homes that the investigator's were not able
to measure where the subjects lived within the past 20
years.
Because of the log normal distribution of radon
concentrations in Iowa, there are many homes with low
radon concentrations.
I do not agree that lung cancer should be rampant in
Iowa, because the relative risk of radon exposure pales
in comparison to the risk posed by smoking. So smoking
will be the overwhelming cause of lung cancer in Iowa.
There are likely several hundred radon related cancers
in Iowa each year. If you look at how many physician's
there are in Iowa, it would be unlikely that every
physician would see at least one radon related lung
cancer.
Bill
> Bill,
> Dr. Alavanaja used track etch dosimeters. Are you saying that those
> readings are worthless?
>
> I agree that reduced smoking is the likely cause Iowa has one of the lower
> incidences of lung cancer among US states, regardless of its elevated radon
> status. In their Citizen's Guide to Radon, the EPA estimates that 2 out of
> every 1000 never smokers exposed to 4 pCi/L will die of radon. With a
> population of 3,000,000 and a much lower smoking average than the US and
> about 60% of the houses with radon levels above 4 pCi/L, it seems that lung
> cancer among never smokers in Iowa should be rampant and subjects easy to
> find. And according to your recent article in the Journal of Exposure
> Analysis and Environmental Epidemiology the number of lung cancers among
> never smokers due to radon are likely much higher. As I recall, your 2000
> study of radon had only 58 cases for never smokers. The model doesn't seem
> to fit the data.
>
> I encourage your radon study to include nonsmokers in other states, both
> high radon and low radon prevalent places.
> Tom
>
> epirad@mchsi.com wrote:
> >
> > Tom,
> >
> > Thanks for your email.
> >
> > If you read Dr. Alavanaja's letter to the editor of the
> > American Journal of Epidemiology, you
> > will see that he attributes this non statistically
> > significant negative finding to poor retrospective radon
> > exposure assessment.
> >
> > Michael C. R. Alavanja, Jay H. Lubin, Judith A.
> > Mahaffey, Ross C. Brownson, Am. J. Epidemiol. 2000 152:
> > 895-896.
> >
> > See also: http://www.cheec.uiowa.edu/misc/rd_review.pdf
> >
> > Regarding Iowa, the lung cancer rates now mainly reflect
> > the relatively low smoking rates in Iowa from 20 years
> > ago or so.
> >
> > In order to perform a study of NEVER smokers, we would
> > need to finish up calibrating the glass-based detectors
> > to use for the study. It is a matter of sample size and
> > required power. We likely could not limit our
> > inclussion criteria to those who lived in the current
> > home for 20 years as we did for the original Iowa Study
> > since it would take too long to recruit subjects. We
> > could propose a study with another state or use glass-
> > based detectors to estimate past radon exposure. In
> > either case, these studies are extremely exspensive and
> > it is not easy to get funding for them.
> >
> > The N. American Pooling of rsidential radon studies
> > will hopefully be published in early 2003 and will
> > include a large pooling of never smokers. I am sure
> > most funding agencies would like to see this study
> > published prior to funding any further residential radon
> > studies of never smokers.
> >
> > Bill Field
> >
> > > Bill,
> > > The Missouri I study was negative for lung cancer in nonsmoking women.
> > >
> > > Alavanja, MC, Residential Radon Exposure and Lung Cancer Among Nonsmoking
> > > Women, J Nat Cancer Inst, Vol 86, No. 24, 12/21/94
> > >
> > > There have been several other studies involving never smokers that were
> > > negative. A curious observation is that the Iowa has one of the the highest
> > > average radon concentrations in the US, but one of the lowest incidences of
> > > lung cancer, according the SEER Report. It seems Iowa would be a great
> > > place to study lung cancer etiology in never smokers, of which radon could
> > > be one of the many factors studied. You've mentioned in previous posts that
> > > this study is forthcoming.
> > >
> > > Now, what if the EPA is correct and about 18,000 lung cancers per year are
> > > attributable to radon. BEIR VI states that if every home is reduced to
> > > below the EPA action level then only about 1/3 of lung (about 6000) cancers
> > > will go away. Why? Because most of the lung cancer numbers are derived from
> > > smoking and very small risk values applied to the large number of people in
> > > the lowest categories.
> > >
> > > In most case-control studies, most of the lung cancers (about 50%-70%)
> > > occur in people who are exposed to < 2 pCi/L; and about 70%-90% of the lung
> > > cancer occur in people with less than 4 pCi/L. Odds ratios cited by authors
> > > on radon levels above 4 pCi/L are based on very small numbers, sometimes as
> > > few as 2 or 3 excess cancers.
> > >
> > > Personally, I think there are very good reasons to be skeptical.
> > > Tom
> > >
> > > 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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> > >
> > > --
> > > 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
>
> --
> 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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