RE: Genetic Effects; Then and Now

[james.g.barnes@att.net]

Which is another interesting point that I failed to mention.  The assumption was that there these mutation events were assumed to be ALWAYS detrimental.  The logic was "man is an advanced organism, and in an advanced organism, mutations must be assumed to be deleterious" (or words to that effect).



Jim Barnes



-------------- Original message from "Ted Rockwell" : -------------- 



Jim:



I think it's pretty well established that no increase in the normal level of birth defects has ever been shown in humans, but I don't know what the best references for that would be.  Jim Muckerheide: can you suggest some refs or offer any other thoughts?  There is also the point that every chromosomal effect is not necessarily a detriment.



Ted Rockwell

-----Original Message-----

From: owner-radsafe@list.Vanderbilt.Edu [mailto:owner-radsafe@list.Vanderbilt.Edu]On Behalf Of James Barnes

Sent: Monday, August 23, 2004 2:54 AM

To: radsafe@list.Vanderbilt.Edu

Subject: Genetic Effects; Then and Now





Dear all;



Last week I sent out a request for information regarding 1950 - 1955 "state of the art" radiation assumptions.  I've gotten back some very interesting references.  Thanks to all of you who sent them along.



One key assumption I find quite interesting.  The general theme is this.  Radiation causes genetic mutations.  These genetic mutations are irreversible.  The number of genetic mutations is directly proportional to the amount of absorbed dose.  Since the number of mutations is proportional to total absorbed dose and are irreversible, it does not matter if the dose is delivered chronically or acutely; they are equally harmful.  This is mentioned in a number of references in the 1959 timeframe, including Glasstone and other reputable sources.



Is this specific assumption still true, or has it been convincingly demonstrated that it is not true (I seem to recall sitting through some PEP sessions where reversibility of genetic mutations were discussed in some detail, but alas I cannot remember who was presenting it).  If not true, what are the key references that refute this early assumption.



Also, just as an aside, I am reading a small book called "No Place to Hide" about a medical doctor who did some of the HP work at the Crossroads test (the test at Bikini Atoll where they blew up the old ships).  Really fascinating stuff; a good evening read.



Jim Barnes