Re: PA Radon -Reply

[Michael S Ford <MFORD@pantex.com>]

Tom, regarding your second question:

>
>2)  Has anyone compiled a complete or near complete list of
>potential carcinogens to which the miner populations have been
>exposed?
>

BEIR IV (pg. 290, Epidemiological Evidence) discusses the fact that
*more than one etiologic agent might be involved* in uranium miner
lung cancers, but it goes on to say that radon daughter exposure is
*generally considered* to be the culprit.  The authors go on to state
that the epidemiological evidence is extremely weak in this area.

In fact, very few studies have undertaken the question of the
synergism between all of the agents that uranium miners might face.
 Those that have are *inconclusive.*  Animal studies looking at
uranium ore exposures in combination with radon daughter
exposures were undertaken for radon exposures ranging from 300 to
8500 WLM.  *Exposure periods ranged from about 1 to 10 months;
exposure rates ranged from less than 10 to hundreds of
working-level months PER WEEK (my emphasis), the majority
averaging approximately 200 to 400 WLM/wk.* (BEIR IV, pg. 432)

The report states that the uranium ore dust appeared to have little
effect on tumor incidence.  However, the uranium dust and radon
were administered on alternating days, and -- at the WLMs and
exposure periods cited -- it is easy to see how the radon levels alone
could dominate the tumorigenesis process.  As is usually the case
with this report, it goes on to state that *too few animals were used
to permit a firm conclusion.*

Since epidemiological studies in BEIR IV and elsewhere have long
lamented the problems of confounding and the lack of reliable
measurements in the miner studies, I would question why the
medicinal use of radon in other countries (e.g., Russia) have not
been considered given the fact that literally millions of people have
been treated under a medical setting with optimal concentrations of
950 WL over 8 to 14 day periods.  

This would seem to be an ideal population to study.  If the EPA and
the CDC were truly interested in determining the health effects of
radon exposure, it would seem that a study of Russian
radon-therapy patients would be the most reliable study group to
examine.

Any comments?

v/r
Michael
*************************
Michael S. Ford, CHP
Texas Radiation Advisory Board
Address:
Radiation Safety Department
Battelle Pantex
Amarillo, TX
806.477.5727 phone
806.477.4198 fax
mford@pantex.com
*************************
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