linear, no threshold theory in the low

[JMUCKERHEIDE@delphi.com]

Dr. Cohen,
 
> Does anyone know of references that defend the linear, no-threshold 
> theory for radiation-induced cancer in the low dose region? The defenses 
> that I know about are essentially saying that we have been using that 
> theory and are not convinced that there is good evidence for abandoning 
> it. But that is not the same as saying we support the theory 
> because..........I am looking for something like the latter.

The closest I can think of is the IARC report that was recently an
international media campaign to promote idea that the linear model is
supported. 

There was also the (media campaign to mislead the public about the) recent
report in the NCI Journal that yet another linear mathematical projection from 
the uranium miner data shows that 14,000 cases of lung cancer are caused by
radon in the US, ignoring again evidence that high radon exposures do not
cause lung cancer and the fact that there is even no epidemiological basis to
associate lung cancer in early miners with the radon in the mines (as noted
here recently, one can make a tentative association from the epi data, but
like iodine deficiency and goiter it needs to be proved by medical association 
which has obviously not been done for radon in the miners). 

I'll also attach my writeup from Dr. Pollycove's review and comments on the
IARC method of "finding" a leukemia association to "support the linear model". 
(It's not science!) 

Regards, Jim Muckerheide 

--------------extract from draft article------------

Professor Emeritus Myron Pollycove, MD, notes that a recent
report by the International Association for Research on Cancer
(IARC) similarly misrepresents dose-response data to report a
"linear model" result. The IARC report chooses to ignore data
that shows lower risk, i.e., a risk decrement. 
   First, in this combined occupational exposure group it chooses
to ignore the most accurate data, the Nuclear Shipyard Worker
Study compared to the early weapons facility workers with their
questionable dosimetry and confounding factors. 
   Then, in a population of 15,825 total deaths, IARC reports on
119 leukemia deaths, excluding non-radiogenic leukemia. The data
show that there are 60 deaths observed with 62.0 expected for
doses of less than 1 cSv, and there are 59 deaths observed with
57.0 expected for doses greater than 1.0 cSv (Table 2). Clearly,
there is no excess leukemia found in this data.

Table 2 IARC Observed/Expected leukemia 
(except CLL) mortality 
(119 deaths in 15,825 total deaths)

Cumulative     Deaths
dose (cSv)     Obs / Exp

  0-           60 / 62.0
  1-           19 / 17.2*
  2-           14 / 17.4
  5-            8 / 9.0
 10-            8 / 6.4*
 20-            4 / 4.7
>40             6 / 2.3*

>1             59 / 57.0
* groups where Observed exceeds Expected

   Dr. Pollycove notes that the IARC report states explicitly in
the Statistical Methods section that they applied (they presumed)
the linear model across 11 dose categories, and that "As there
was no reason to suspect that exposure to radiation would be
associated with a decrease in risk..., one-sided tests are
presented throughout." This states that they explicitly ignore
all contrary data.
   For the table, the eleven dose categories were collapsed to
seven, resulting in greater-than-expected leukemias in three of
the seven dose groups (the * groups in Table 2). Since only
positive data are allowed to be considered, only the data from
these three greater-than-expected dose groups are used, even
though these dose groups are not even contiguous. Since the
selected data are not significant, the IARC performs a Monte
Carlo calculation on 5 000 trials (effectively multiplying the
data by roughly a factor of 100) to "find" that the results show
a "significant" linear dose-response "trend".
   This "result" was then the subject of a world-wide media
campaign, reasonably reported even in Nuclear News, that the
"linear model" is confirmed. This report was widely distributed
long before the data and analysis were published and available
for review.
   IARC also similarly reports that the 44 multiple myeloma
deaths are "found significant", noting that this is "attributable
primarily to the associations reported previously ... in the
Hanford and Sellafield cohorts." This note indicates that they
are aware, without so stating, that this "association" is not
found in other cohorts and is generally considered to be
erroneous in these studies, consistent with the weakness in the
dosimetry and the confounding effects. (The study also reports
that cancer relative risk is 0.99 and leukemia is 1.22 at 10
cSv.)
   These are the sole bases for the "conclusion" that the IARC
study finds that the data is consistent with the linear model.
   Clearly, if all data were considered by IARC without
arbitrarily excluding contrary data, and presuming the linear
model to represent the data, the mortality data in these combined
populations do not support the "linear model." As Dr. Luckey has
found, objectively examining all the data in each of the cohorts
indicate positive/beneficial effects for the exposed populations,
a result which would be reasonably expected to result in a
positive (beneficial) effect in the combined populations. The
IARC, consistent with BEIR, NCRP and other government data
presentation, capriciously misrepresents the data to conform to
the costly radiation protection policy mandate.
-J. Muckerheide