Re: What is hormesis? -Reply

[Charles Willis <CAW@nrc.gov>]

Chris,

Thanx for posting Dr. Parthasarathy's article on hormesis.  It is interesting but I
feel impelled to add a couple of comments.

First, in discussing hormesis, it seems important to note the near-universality of
the phenomenon.  That is, so far as we know, every substance that is beneficial is
harmful at sufficiently high doses.  Even water is toxic if one drinks too much. 
Furthermore, many substances that are generally viewed as dangerous are
manifestly beneficial in small doses; much of  pharmacology and medicine is based
on this phenomenon.  Radiation hormesis may be debatable, but the general
hormesis phenomenon is beyond question.

Second, it seems undesirable to address radiation's adverse health effects, and
human knowledge concerning these effects, as something relatively recent.  The
effects, of course have been with us for some time; the report on the Joachimstahl
miners by Paracelsus in about 1530 A.D. is an obvious example.  As for our
knowledge of radiation effects, of course, it began with the observation of
"deterministic" effects in 1896, and continued with Frieben's reporting radiation
carcinogenesis in 1902.  A year later Heineke induced leukemia with radiation. 
Even radiation mutageneses was reported by Thomas Hunt Morgan ("the father of
American genetics) and his students in 1911.  (It seem odd that we so often hear
mention of  Hermann Muller without mention of  either his being one of Morgan's
students or of  his being a sincere communist, but that is another issue.)  This is
not to denigrtate the A bomb survivor work; the RERF  data  provide the best
basis we have for radiation risk estimates and the also confirm laboratory studies
showing that the genetic effects of radiation are less dire than was once feared. 
Still, it seems significant that radiation in medicine is as old as aspirin and that
radiation risks are older than automobiles.

Too much said; I will sign off.

Charlie Willis
caw@nrc.gov