Re: do we _need_ radiation?

[melissa (M. Woo)]

> It would be expensive, but maybe not outrageously so, to raise mice with
> exposure to radiation restricted to about a percent of the norm.  
> 
> The cages would need to be in the sorts of caves that are used for nutrino
> telescopes, of course, and their grain would need to be grown indoors with CO2
> obtained by burning coal [which has essentially no C14, being hundreds of
> half-lives old].  Potassium would be a problem, but mice need little enough
> that isotope separation is not out of the question, and of course it can be
> recycled from urine and feces once you have an initial stock.  The plants must
> be grown hydroponically.

In reality, attempts to eliminate all possible factors would probably be
extremely difficult.  "Radiation hormesis" has been a pet subject for my
former thesis advisor for quite some time now.  The last time I spoke to
him on the subject, he had concluded that the experiments performed in
which he had confidence that all confounding factors had been reasonably
eliminated seemed to show that a low level of radiation itself did not
appear to make a difference.  (sorry -- can anyone parse that last
sentence?)  He seemed to think that hormesis was demonstrated in experiments
in which some other factor in combination with radiation was varied.

Then again, that's just one man's opinion, so take it with a grain of salt
(or radioactive salt substitute, if you like).

As an aside, he really despises how most people define radiation hormesis.
Apparently, most define it as a beneficial effect of low doses of
radiation.  Since "beneficial" is a subjective term, and depends heavily
on its subject (e.g., what is beneficial for a cancer patient is not
beneficial for the cancer cells in the patient), he always preferred to
define radiation hormesis as effects of low dose radiation which cannot
be extrapolated from knowledge of the effects of high doses of radiation.

Umph, I'm debating whether or this subject would be more appropriate for
the radiobiology mailing list, rather than this one...

-- 
Melissa Woo                       | University of Illinois at Urbana-Champaign
Health Physicist                  | Environmental Health & Safety Bldg., MC225
office phone: 1.217.244.7233      | 101 S. Gregory St., Urbana, IL  61801
m-woo@uiuc.edu                    | http://www.cso.uiuc.edu/ph/www/m-woo