plutonium

[FRAMEP@ORAU.GOV]

According to Newell Stannard (Radioactivity and Health p 367, 1988
Battelle Memorial Institute, DOE/RL/01830-T59)), and he should know, the
statement that plutonium is the most toxic element known to man
was"made during the war years [WWII] perhaps in part to ensure
support for the needed protection measures, in part to secure full
cooperation of the workers, and in part because the accumulating data
were pointing in that direction."  Stannard's book summarizes the various
animal studies, and human experiences with plutonium and nicely
addresses the issue of its toxicity.

(Initially during the Manhattan Project, the MPBB for Plutonium was
pegged at 5 ug, 50 times that for radium, but studies indicated that
plutonium's longer biological half life meant that the 5ug  MPBB was too
high)

When Robert Stone of the Met Lab in Chicago was asked what quantity
of Plutonium  it was acceptable for a worker to inhale, he replied "None
at all". I've seen similar statements attributed to him but can't locate them
right now. I wouldn't be too surprised if Stone were the prime instigator
of the "most toxic" label.

On the cover of No Place to Hide by David Bradley (1948), in which he
describes his experiences in the early atomic tests e.g. Crossroads, it
states "....the horrible menace of free plutonium remained - the most
insidious poison known". 

Just speculation, but to add to what Newell said, the most toxic business
was probably meant as an intentional exaggeration because plutonium's
properties were relatively unknown, it was the most significant
radiological hazard at several wartime sites, it was very difficult to
measure plutonium surface contamination (so safety depended on blind
obedience to instructions), and it was almost impossible to evaluate once
inside the body.

All of these things continued to be important issues during the
Crossroads tests where the Navy personnel, whose ships might have
been heavily contaminated,  did not have had a good appreciation of
radiation safety. 

In any event, its a bit disingenuous to lay the blame at the feet of the anti
nukes for repeating a fallacy we in the rad protection community started
- as much as we would like to blame them - both sides are responsible.

Paul Frame
Professional Training Programs
ORISE
framep@orau.gov