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Re: Response to Cohen's $2500 offer



Dear Radsafe Group:

JMUCKERHEIDE@delphi.com wrote, in part:
> 
> Group,
> 
> I'd add to Wade's statement that:  Ken Bogen's model applies not "generally
> accepted principles of radiobiology", but rather the current fundamental
> knowledge of biology and oncology of the cell and organism, reflecting current
> explicit knowledge of the cellular and molecular processes and response to
> damage, beyond just "radiobiology". His biology model predicts Cohen's results
> and uranium miner data by reflecting current processes and damage/repair
> mechanisms. 
-- 
I'd prefer those of you who wish to understand exactly what Bogen has
done to read his paper. It is scheduled to appear in "Human and
Ecological Risk Assessment", this year, hopefully soon. Preprints can be
obtained from the author,
Dr. Kenneth T. Bogen
LLNL L-396
Livermore CA
94550-9900
ph. 5120 422-0902
email <bogen@llnl.gov>

For those of you who wish only to have a general knowledge of his work,
here is the abstract.
Bogen, K. T. Do U.S. county data disprove linear no-threshold
predictions of lung cancer risk for residential radon?-A preliminary
assessment of biological plausibility. Lawrence Livermore National
Laboratory, University of California UCRL-JC-123219 Rev.2 :45; 1996
Abstract:
Lung-cancer mortality (LCM) is elevated in underground miners who
chronically inhaled the mutagenic, cytotoxic alpha-decay products of
radon gas. Epidemiologic studies of LCM rates vs. residential-radon
concentration levels are generally considered inconclusive. However,
Cohen, Health Physics 68, 157-174,1995) has hypothesized that data on
LCM vs. residential radon concentrations at the U.S. county level are
clearly inconsistent with a linear no-threshold (LN) dose-response
model  and rather are consistent with threshold or hormesis model.
Cohen's hypothesis has been criticized as "ecological fallacy",
particularly because LN (but not threshold or hormesis) models are
generally considered biologically plausible for agents like alpha
radiation that can damage DNA in linear proportion to dose. To assess
the biological plausibility of Cohen's hypothesis, a preliminary study
was made of whether a biologically realistic, cytodynamic 2-stage (CD2)
cancer model can provide a good, joint fit to Cohen's set of U.S. county
data as well as to under-ground miner data. The CD2 model used adapts a
widely applied, mechanistic, 2-stage stochastic model of carcinogenesis
to realistically account for interrelated cell killing and mutation
(both assumed to have a LN dose-response), and incomplete exposure of
stem cells. A CD2 fit was obtained to combined summary data on LCM vs.
radon-exposure in white males in 1,601 U.S. counties (from Cohen) and
white male Colorado Plateau (CP) uranium miners (from the National
Research Council's "BEIR IV" report). The CD2 fit was shown to: (i) to
be consistent with the combined data; (ii) to have parameter values all
consistent with biological data; and (iii) to predict inverse
dose-rate-effects data for CP and other radon-exposed miners, despite
the fact that optimization had not involved any of these dose-rate data.
The latter data were not predicted by a simplified CD2 model in which
all stem cells were presumed to be exposed.  It is concluded that this
study provides preliminary evidence that Cohen's hypothesis is
biologically plausible.