Newsgroups: sci.environment
Subject: Human Genetic Effects from Irradiation
From: zcbag@cnfd.pgh.wec.com (B. Alan Guthrie)
Date: 12 Feb 1997 17:53:33 GMT

In a separate thread in this newsgroup, Dr. Freisel has asked
for references backing up the hypothesis that we have had no
observed genetic effects in humans due to exposure to ionizing
radiation.  An easily accessible reference is the Encyclopaedia
Britannica.  In Vol 15 of the 15th Edition, on page 420, in an
article entitled "Radiation Injury," we find,


        Without any unusual radiation exposure, about
	1 percent of newborn human beings show some
	visible defect in development which might be
	caused by a mutation.  Little is known about
	the role of already existing radiation levels
	[background radiation] in producing these
	abnormalities, but there is good reason to
	believe that a great majority of them are
	caused by factors not related to radiation.

	Some of the most direct information available
	in the human being has come from the offspring
	of atomic bomb casualties in Japan.  It appeared
	at first that there was an alteration in sex
	ratio from previously irradiated parents,
	suggesting selective fetal mortality, but
	this finding has not been substantiated.
	The pregnancies from this group, when compared
	to those of nonirradiated controls, are now
	reported as failing to show any detectable
	increase in stillbirths, neonatal deaths,
	gross malformations, or mortality during
	childhood.

Another reference is the Fifth Lecture in the Lauriston
S. Taylor Lecture Series in Radiation Protection &
Measurement, which was given by Dr. James Crow in 1981.
Dr. Crow received his PhD in Biology in 1941, from the
University of Texas-Austin, which at that time was a
center for research in radiation and population genetics.
He is (assuming that he is still among the living and
still acitve) on the faculty at University of Wisconsin-
Madison where he has served as Professor of Zoology in
the College of Letters and Science, Professor of Genetics
in the College of Agriculture and Life Sciences, and
Professor of Medical Genetics in the College of Medicine.
He has twice served as joint chairman of the Departments
of Genetics and Medical Genetics.  His lecture was
entitled, "How Well Can We Assess Genetic Risk?  Not
Very," and in this lecture he made the following statement,
"As it is, even the studies in Hiroshima and Nagasaki,
which have yielded unequivocal evidence of delayed
somatic radiation effects, have produced no statistically valid
evidence of genetic change. (page 11)"

His lecture was published by the National Council on Radiation
Protection and Measurements.

Lastly, you might want to consult the BEIR V report, Chapters
2 and 7, published in 1990.  BEIR stands for Biological Effects
of Ionizing Radiation, and this report probably represents the
best scientific consensus on the subject in 1990.  This report
should be readily available at Hanford, and I am afraid that
I might improperly summarize its results should I try to
paraphrase them.



--
alan.guthrie@cnfd.pgh.wec.com

"I have to confess it has crossed my mind that you could not be a
Republican and a Christian."   Hillary Rodham Clinton  Feb 6, 1997