RE: Radiation as a teratogen

["Franta, Jaroslav" <frantaj@aecl.ca>]

> Gibbs, S Julian[SMTP:s.julian.gibbs@vanderbilt.edu] wrote on Monday, June
> 14, 1999 5:08 PM
> 
> YES!!  Radiation, in sufficient doses, produces congenital 
> anomalies. 
	....In the Japanese atomic bomb survivors, 
> irradiation in utero produced short stature, microcephaly, 
> and mental retardation. 
<><><><><><><><><><>

Maybe you can enlighten me on this, but according to my Webster
dictionary, the definition of teratology is: [Gk teras marvel, monster +
-logy
akin to]: the study of malformations, monstrosities, or serious deviations
from the normal type in organisms... in other words, slight physical or
mental growth retardation do not appear to fall into this category, even
though they
involve in-utero exposure. 


...furthermore, the RERF says,

"There is no statistically demonstrable increase in major birth defects
considered in total or in any specific type among the children of
atomic-bomb survivors. This assertion rests on a continuous prospective
surveillance of the children conceived and born in Hiroshima and Nagasaki
after the bombings. The survey began in the late spring of 1948 and
continued over the following six years. During that time, 76,626 newborn
infants in Hiroshima and Nagasaki were examined by physicians employed by
the Atomic Bomb Casualty Commission (ABCC), the predecessor of the present
Radiation Effects Research Foundation."

"Among the 65,431 registered terminations for which the parents were not
biologically related to one another, 594 (0.91%) resulted in a child with a
major birth defect. This finding accords well with another large series of
Japanese births studied at the Tokyo Red Cross Maternity Hospital in which
radiation exposure was not involved, and the overall frequency of malformed
infants was 0.92%. The most common of the defects seen in Hiroshima and
Nagasaki, exclusive of congenital heart disease, were anencephaly, cleft
palate, club foot, cleft lip with or without cleft palate, polydactyly (an
additional finger), and syndactyly (the fusion of two fingers). These seven
abnormalities, common in all human populations, accounted for 445 of the 594
malformed infants born to parents who were not related to each other.
Neither the overall frequency of major birth defects nor the frequencies of
the seven just enumerated differ significantly with parental exposure.
Similarly, in the 18,876 children whose parents were not related to one
another and who were re-examined at age eight to ten months, 378 had one or
more major defects, but again, the frequency does not vary consistently with
parental exposure."
....a clinical study of the kind described would have been able to
detect a doubling of the rate of major congenital malformations if such had
occurred."


Lastly, something about  "deformities gruesome beyond belief" from URL
http://www.nando.net/newsroom/ntn/world/120998/worldt_8718.html
(Associated Press ) 
..odd that epidemiological research of Japanese A-bomb survivors (the
largest high-dose group by far) or that of the Radium dial painters (chronic
doses to ~20,000rads) never came across anything like this !

jaro

frantaj@aecl.ca
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