Newsgroups: misc.education.science
From: hoey@aic.nrl.navy.mil (Dan Hoey)
Date: 1995/04/11
Subject: Radiation reputations (Re: Americium in smoke Detectors)

> mu...@erich.triumf.ca (FRED W. BACH , TRIUMF Operations) writes:

> #   ... If this isotopt were called plutonium, people would
> #   freak out, because of it's bad reputation.  But since this isotope
> #   is called Americium, like "America", foolish people think it's
> #   motherhood and apple pie.  Yet the regulations are similar in my
> #   books up here.

cbet...@unlinfo.unl.edu (clifford bettis) writes:

> ... I agree that the relative reputations of Am and Pu is a puzzle.
> I think it must have to do with the weapons application of Pu as
> boooth elements represent a similar health risk in small quantities.

There is a possible explanation in the article "Atomic Overreaction"
by Jeff Wheelwright, in the April 1995 _Atlantic Monthly_, p. 26 ff.
During the Manhattan project, chemists did not want another episode
like that of the radium watch painters.  Plutonium seemed like another
possible danger, but they could not quantify it, and it took a lot to
scare people about industrial contamination back then.  So they told
the workers it was possibly the most dangerous substance on earth.
Eventually this got picked up by the _Ripley's Believe it or Not_ and
the _Guinness Book of World Records_, and a folk legend was born.

People demonstrate against space launch of radiothermal generators
because they contain plutonium.  When a half kilogram of plutonium
smuggled from Moscow was confiscated in Munich, the press was full of
wild surmise about whether Munich could have been held ransom by
terrorists threatening to toss it in the reservoir.  In "Plutonium's
Bad Rep" (March-April 1995 _American Scientist_, pp. 132-33), David
Schoonmaker checked up and found that the N.Y. Times and L.A. Times
had no scientific source for these stories.  He calculates a 40
millirem exposure per person (assuming even dispersal through the
water supply) as compared to 300 millirem annual background exposure.

I'm not suggesting that plutonium is not dangerous, just that its
hazards have apparently been exaggerated out of proportion.  I think
Americium escaped this fate, not because of its cute name, but because
it was not produced in quantities in the 1940s and 1950s.

As for the Americium source in a smoke detector, it sure seems like a
good idea to keep it sealed unless you know what you're doing--which
the teacher and student apparently did not.  I would really like to
hear how that episode turned out.

Dan Hoey
Hoey@AIC.NRL.Navy.Mil