From: jac@ibms48.scri.fsu.edu (Jim Carr)
Subject: Re: Mushroom Cloud Physics
Date: 09 Mar 1999
Newsgroups: sci.physics,alt.folklore.science,alt.war.nuclear

jac@ibms48.scri.fsu.edu (Jim Carr) wrote:
}
} You can also compare radiation sources with the same strength but
} different chemical properties to account for what radiation might
} be doing.  By the way, the LANL report on the Pu injection studies
} does describe acute toxicity studies on rats that put the LD50 at
} about 20 to 60 micrograms per kg body weight.

In article <36e3f632.2996963866@nnrp3.crl.com>
careys@paciolan.com (Carey Sublette) writes:
>
>Do you have the LANL report number handy?

 I do now.  This was from a side bar on page 205 of the "Radiation
 Protection and the Human Radiation Experiments" issue of "Los
 Alamos Science" from 1995 -- issue number 23.

 I think it is available on the web, and they often have back
 issues available [e-mail: lascience@lanl.gov].

 The article itself has a bibliography but no footnotes in the text.
 Most likely candidates for primary source data would be some books
 from circa 1950 that don't seem clearly human research related.
 "Biological studies with Polonium, Radium, and Plutonium" (1950,
 McGraw-Hill) ed. Robert M. Fink seems like a good candidate.  Also
 "Industrial Medicine on the Plutonium Project: Survey and Collected
 Papers" (1951, McGraw-Hill) ed. Robert S. Stone.

 They also list www.ohre.doe.gov and the public reading room adjacent
 to the Bradbury Library at LANL as archive locations for documents.

>Does the report clearly state that the acute toxicity is due to
>*chemical* effects?

 No.  It is in a section labeled "acute toxicity", but the only
 mention of chemical toxicity was in the procedure used to set
 a safe level for humans from animal experiments.

>A quick estimate indicates that since plutonium is
>a bone seeker, and assuming that 20% of the body mass of a rat is bone
>tissue, that  60 mcg/kg of Pu-239 could produce up to 150 rem/day of
>exposure to bone marrow - enough to wipe it out in 3-5 days.

 That occured to me, but I did not crunch the numbers since I figured
 you would.  ;-)  The raw data the mentioned said 700 to 1000 micro
 grams caused half the animals to die in 30 days, and 200 to 600
 micro grams caused half to die in 150 days; no deaths after 420 days
 for 10 micro gram injections.

--
 James A. Carr   <jac@scri.fsu.edu>     | Commercial e-mail is _NOT_
    http://www.scri.fsu.edu/~jac/       | desired to this or any address
 Supercomputer Computations Res. Inst.  | that resolves to my account
 Florida State, Tallahassee FL 32306    | for any reason at any time.

From: jac@ibms48.scri.fsu.edu (Jim Carr)
Subject: Re: Mushroom Cloud Physics
Date: 02 Mar 1999
Newsgroups: alt.folklore.urban,sci.physics,sci.skeptic,alt.folklore.science,
	alt.war.nuclear

 ... significantly reduced followups ...


In article <36DB31F2.72BC@gazonk.del>,
"Foobar T. Clown" <fubar@gazonk.del> writes:
}
} Can somebody explain to me how plutonium got such a bad reputation?

In article <F7y1w0.2pC@midway.uchicago.edu>
meron@cars3.uchicago.edu writes:
>
>Three guesses:
>
>1)  Intentional misinformation by defense organizations, aimed at
>deterring anybody who might consider stealing the stuff.
>2)  Intentional misinformation by anti-nuclear activists, for obvious
>reasons.
>3)  Plain media hype.  That's the "don't attribute to malice what can
>be explained by stupidity" option.

 Items 2 and 3 feed on each other, but the reputation of plutonium
 is not based on misinformation.  Only the hyperbole is overdone.

 The permissible exposure level for Plutonium was set 50 times higher
 than for radium (5 microgram rather than 0.1 microgram body burden)
 based on a comparison of physical effects, then lowered to 1 microgram
 because of uptake / concentration differences seen in animals.   It
 was lowered further to 0.65 micrograms after the human experiments
 and observations of accidental exposures.  Gram for gram, radium
 is more dangerous.  However, the numbers appear reversed when they
 are expressed as 100 nanocuries (Ra) and 40 nanocuries (Pu).

 Those numbers alone do not say that the _regulatory_ level at which
 you are no longer allowed to work with the stuff was set a factor
 of 10 below the level where experience (with Ra) showed no effects.

 A fraction of a microgram body burden *is* a small number.  The stuff
 *is* dangerous if it gets into your body.  A certain level of paranoia
 does help keep accidental exposures to a minimum ... and as a result
 there is very little data on large Pu exposures.  It does pay to treat
 dangerous materials as dangerous materials.  The key to safety is to
 realize that you can operate safely if you recognize danger for what
 it is and treat it accordingly.

 I suspect that somewhere along the line someone dropped "among the"
 from in front of "most dangerous" and the moniker stuck.  Pictures of
 Nagasaki help, of course, because many people make no distinction
 between radiation and bombs.  Here is where Item 2 plays a role.
 Cassini is a recent example.  As others have noted, there is a
 difference between releasing some quantity and getting it into
 people.  We vaporized huge amounts of 239Pu (maybe a ton?) in the
 atmosphere, more than enough put a microgram in every person, an
 amount easily detected in radiation workers.  It is not there.

 But that does not mean it is safe to lick your radium paintbrush
 or turn 239Pu on an open lathe.

--
 James A. Carr   <jac@scri.fsu.edu>     | Commercial e-mail is _NOT_
    http://www.scri.fsu.edu/~jac/       | desired to this or any address
 Supercomputer Computations Res. Inst.  | that resolves to my account
 Florida State, Tallahassee FL 32306    | for any reason at any time.

From: jac@ibms48.scri.fsu.edu (Jim Carr)
Subject: Re: Mushroom Cloud Physics
Date: 10 Mar 1999
Newsgroups: sci.skeptic,alt.folklore.science,alt.folklore.urban,sci.physics

 ... note reduced followups ...


Dan Drake wrote:
}
}Quite so.  But in this case (having now taken the trouble to look it up)
}we're talking hundreds of milligrams of caffeine in a short time without
}any reported incidence of lethal effects.  Now we can consider the effects
}of hundreds of milligrams of plutonium.

In article <Pine.GSU.4.05.9903101223460.10590-100000@garcia.efn.org>
Dr H <hiawatha@efn.org> writes:
>
> According to my psychopharmacology text a toxic dose of caffeine is
> around 8-10 grams.  A cup of coffee has ~100 milligrams, or roughly
> 1-2% of the toxic dose.

 And because of inefficient uptake by the GI tract, the corresponding
 exposure is a few micrograms of 239Pu, less than the occupational
 limit and also a small fraction of the 'toxic' dose if the Pu is
 in soluble form.  Less otherwise.

> Also, caffeine is water soluble, and is processed and excreted by the
> body fairly rapidly.  The same can not be said for plutonium, in any
> form.

 What cannot be said of it?  Some of it is excreted.  (See the Pu
 studies.)  This reduces the final body burden somewhat.

--
 James A. Carr   <jac@scri.fsu.edu>     | Commercial e-mail is _NOT_
    http://www.scri.fsu.edu/~jac/       | desired to this or any address
 Supercomputer Computations Res. Inst.  | that resolves to my account
 Florida State, Tallahassee FL 32306    | for any reason at any time.

From: jac@ibms48.scri.fsu.edu (Jim Carr)
Subject: Re: Mushroom Cloud Physics
Date: 10 Mar 1999
Newsgroups: sci.skeptic,alt.folklore.science,alt.folklore.urban,sci.physics

jac@ibms48.scri.fsu.edu (Jim Carr) wrote:
|
| rab42@my-dejanews.com wrote:
| } Some years ago, someone responded to the hysterical faction of the
| } anti-nuclear groups by pointing out that, weight for weight, *caffeine*
| } is more deadly than plutonium.  Does that report have anything to say
| } on this?
|
| dd@dandrake.com (Dan Drake) writes:
| >I have seen the amount of caffeine in a cup of coffee or tea (or a Coke)
| >given *milli*grams.  Is this all a lie?
|
| All well documented.  (You might not realize that some familiar
| legal drugs are often consumed in an amount that is a significant
| fraction of a dangerous dose.  Alcohol is a prime example.)

dd@dandrake.com (Dan Drake) writes:
>
>Quite so.  But in this case (having now taken the trouble to look it up)
>we're talking hundreds of milligrams of caffeine in a short time without
>any reported incidence of lethal effects.  Now we can consider the effects
>of hundreds of milligrams of plutonium.

 Consumed the way he specified?  No problem.  Actually, the challenge
 was more like a gram or two.  Although not fatal to a healthy person,
 that amount of caffeine could cause problems for a person with heart
 disease or high blood pressure.

 Perhaps you are unaware of the GI uptake of Pu in soluble form.

| >Answer, I bet: Take some Pu orally in metallic form (finely ground, of
| >course -- being careful no to inhale it if it's too finely ground) and
| >probably it will pass through without a significant amount being absorbed.
| > (Take Maalox with it to be safe?  Just speculating,)  But taking equal
| >quantities of caffeine and plutonium in a form that can be absorbed?
| >Ridiculous.
|
| Not at all.  The assertions he based his challenge on were not
| about Pu in a particular chemical form, but general remarks that
| made no distinction about what form it was in.  He was probably
| well aware of the data on uptake of plutonium by the GI tract
| in its more common forms.

>I'm not quite sure what is `not at all' what in this paragraph.  (This is
>not for rhetorical effect: I'm really not sure what you're saying.)

 It would help to see the remarks previous to yours, but my comment
 was directed at your claim that it is ridiculous to base the challenge
 on the conditions specified when Pu is declared to be ultra dangerous
 by some folks.  Since those statements tend to be unqualified rather
 than specific (and they would look pretty silly if they were spelled
 out in detail), it is fair to say that you will swallow a certain
 amount rather than inhale a certain other amount, and it is fair to
 leave the chemical form unspecified.

>Is it
>not all ridiculous to claim that weight for weight, caffeine is deadlier
>than plutonium?  Or not at all important what chemical form you use when
>you swallow a one-time dose of it?

 He did not say that.  He just issued a challenge and was not taken
 up on it.  That challenge was a test of a statement made by another
 person, and showed the other person would not stand behind it.

>If one makes _no_ distinction about what form the Pu is in, then one is
>not ruling out any form, including inhalation of an extremely finely
>divided powder.

 Except he was the one issuing the challenge concerning the blanket
 statement that implied Pu was equally dangerous in any form and
 when consumed under any circumstances.  We all know the risk from
 inhalation.  The situation was that the person he challenged had
 not said anything about forcing each person to ihhale powder in
 a certain form.

>OTOH if the statement quoted at the top merely means "If you take it in
>the right form (ingesting a one-time glob of it) then it's not so bad"
>then I stand by my statement that this is the kind of junk science (forgot
>to use that term the first time -- thanks for the opportunity to revise)
>that's to be expected from the hysterical faction of the pro-nuclear
>groups.

 Except it was based on the junk science of the anti-nuclear groups
 who implied that Pu was as dangerous in any form consumed under any
 conditions as it _is_ when inhaled.  Thus the challenge was an
 experimental test of that PR-oriented junk science, and served its
 purpose at the time.

 It shows that Pu does not have the properties that are normally
 ascribed to it in the media.

--
 James A. Carr   <jac@scri.fsu.edu>     | Commercial e-mail is _NOT_
    http://www.scri.fsu.edu/~jac/       | desired to this or any address
 Supercomputer Computations Res. Inst.  | that resolves to my account
 Florida State, Tallahassee FL 32306    | for any reason at any time.

From: jac@ibms48.scri.fsu.edu (Jim Carr)
Subject: Re: Mushroom Cloud Physics
Date: 16 Mar 1999
Newsgroups: sci.skeptic,alt.folklore.science,sci.physics

In article <7c8k53$dd4$1@news.fsu.edu>,
jac@ibms48.scri.fsu.edu (Jim Carr) wrote:
|
| In article <7c89po$onp$1@nnrp1.dejanews.com>
| Chad Ghostal <maudweeb@my-dejanews.com> writes:
| >The original ass-ertion was that caffeine was more toxic than Pu239.
|
| Incorrect.  The original claim was that 239Pu was the most toxic
| substance around.  We know that is false.

In article <7ck2qo$mvf$1@nnrp1.dejanews.com>
Chad Ghostal <maudweeb@my-dejanews.com> writes:
>
>OK, maybe I should have said meta-thread.  I was using hyperbole
>to make a point.

 The only point you made was that you missed the original issue.

>So, you are *that* sure that Pu239 is not one
>of the most toxic substances known to humankind.

 What leads you to that conclusion?  I did not say that.

 I only know that there is at least one material that is more
 strictly limited than 239Pu, and have seen posts that identify
 some other things that are known to kill at a lower level than
 exposures to Pu that are 'safe'.  I can also think of many other
 isotopes that are more dangerous but less famous.

 We know the stuff is very dangerous, and have set industrial
 exposure levels accordingly -- well *below* the level where
 adverse effects are expected.  However, because of those limits,
 very few people have ever been exposed to amounts much in
 excess of those limits and thus there is very little human
 epidemiology data on actual harm.  Persons who have been
 exposed to microgram quantities do not show any significant
 pattern that would lead to the conclusion that the current
 exposure limit is unsafe.

>I am not convinced,
>so I guess I disagree with you.  Since Pu239 is mildly radioactive,
>HL ~ 24,000 yrs, it's toxic properties are the limiting factor in
>control of this element.

 Not so, as some posted calculations have shown.  A half life of
 24,000 years is not "mildly" radioactive.  A lump of the stuff
 is warm to the touch.  Granted it is not like the Cr source I was
 reading about for our research group's spring project on solar
 neutrinos (2 MCi, puts out 400 W), but it is hot stuff.  The
 "toxicity" limits are all based on its radioactivity.

 However, when you say that 239Pu is only mildly radioactive, you
 disprove your original assertion that it is the most toxic
 substance around.  Other isotopes that are more radioactive
 (like 226Ra) are gram-for-gram more dangerous than 239Pu.

>Well, if you ignore the fact that it only
>takes 15.2 kgms to go critical.  But I digress.

 So don't.  That is not relevant and mentioning it only shows
 you think your main argument is weak.

>I don't have my
>conversion tables with me, curies/grams, but since it's not that
>radioactive I will guess 10 nanocuries is more in the microgram range.

 No, the factor is only about 10, and micrograms are not "toxic".

 You are confusing occupational limits with toxicity, a common
 problem since it is the safe level that is used as the death
 level by certain people.  The studies on rats done before the
 human injection experiments set the "safe" level for _acute_
 effects at about 10 micrograms per kg body weight when the Pu
 is injected.  The experiments were more than a factor of 100
 below this level (as is the lifetime body burden limit) and
 no acute effects were seen in those people.

 The studies on radium, where there is excellent data due to the
 large population exposed and the range of exposures, set the
 _tolerance_ level at 100 nCi, i.e. 100 ng of 226Ra.  The initial
 239Pu tolerance level was set at 50 times this, since it is
 50 times less dangerous (taking alpha energy and daughters into
 account) than 226Ra, then later cut by a factor of 5 because of
 biological concentration effects as those were discovered.

--
 James A. Carr   <jac@scri.fsu.edu>     | Commercial e-mail is _NOT_
    http://www.scri.fsu.edu/~jac/       | desired to this or any address
 Supercomputer Computations Res. Inst.  | that resolves to my account
 Florida State, Tallahassee FL 32306    | for any reason at any time.