Plutonium really the "most toxic poison known to man"?
Grinch
With NASA getting ready to launch the Cassini Saturn probe, loaded
with plutonium in lieu of Everready batteries, we're hearing a lot of
scare scenarios about what could happen if the rocket blows up --
colorful images along the lines of "a fine dust of plutonium
descending from a burnt-up spacecraft to make a good chunk of Florida
uninhabitable for 12,000 generations", which was just presented in a
NYC newspaper.
Most of the discussion is about the risk of accident to the
spacecraft, but I'm more curious about the real toxicity of plutonium.
I've heard the line about "the most toxic substance known to man"
countless times, but when I tried to look into it on the Web I found
the research of Dr. Bernard Cohen, a physics professor at the
University of Pittsburgh and former president of the Health Physics
Society, who has calculated that ingesting a gram of plutonium
increases radiation-related health risks only about as much as
spending six months at 5,000 feet instead of sea level; say, in Denver
instead of New York.
Apparently Dr. Cohen has publicly offered to eat as much plutonium
as Ralph Nader would eat pure caffeine, saying the health risk is
comparable, but so far Mr. Nader has declined.
I'm no expert in this field but Dr. Cohen's work seems to be peer
reviewed. A sample is at http://www.syd.suburbia.net/~rlong/ff/p22.htm
Also, I found a bare-bones version of a story about 26 people who
accidentally ingested more than what is now deemed a "lethal" amount
of plutonium in the 1940s while working on the Manhattan Project, and
who were thereafter monitored by medical types with interest.
Forty years later, the expected number of deaths among a randomly
selected demographically comparable group was ten, three from cancer.
But among the 26 there were only four deaths, and just one from
cancer. A small sample size to be sure, but hardly evidence of the
most toxic substance known to man.
This was at
http://ans.neep.wisc.edu/~ans/point_source/AEI/may95/plutonium_eff.html
Any more info on this anywhere?
All this is an *awful* long way from plutonium's "most toxic
substance" reputation, even by the standards of urban legends.
So really and truly, how toxic is plutonium?
Regards
Lloyd R. Parker
Grinch (OldN...@mindspring.com) wrote:
:
: With NASA getting ready to launch the Cassini Saturn probe, loaded
: with plutonium in lieu of Everready batteries, we're hearing a lot of
: scare scenarios about what could happen if the rocket blows up --
: colorful images along the lines of "a fine dust of plutonium
: descending from a burnt-up spacecraft to make a good chunk of Florida
: uninhabitable for 12,000 generations", which was just presented in a
: NYC newspaper.
:
: Most of the discussion is about the risk of accident to the
: spacecraft, but I'm more curious about the real toxicity of plutonium.
:
:
: I've heard the line about "the most toxic substance known to man"
: countless times, but when I tried to look into it on the Web I found
: the research of Dr. Bernard Cohen, a physics professor at the
: University of Pittsburgh and former president of the Health Physics
: Society, who has calculated that ingesting a gram of plutonium
: increases radiation-related health risks only about as much as
: spending six months at 5,000 feet instead of sea level; say, in Denver
: instead of New York.
: Apparently Dr. Cohen has publicly offered to eat as much plutonium
: as Ralph Nader would eat pure caffeine, saying the health risk is
: comparable, but so far Mr. Nader has declined.
: I'm no expert in this field but Dr. Cohen's work seems to be peer
: reviewed. A sample is at http://www.syd.suburbia.net/~rlong/ff/p22.htm
The chemical toxicity of plutonium alone is enough to label anybody who
says he would ingest it as a bona fide nut case.
:
: Also, I found a bare-bones version of a story about 26 people who
: accidentally ingested more than what is now deemed a "lethal" amount
: of plutonium in the 1940s while working on the Manhattan Project, and
: who were thereafter monitored by medical types with interest.
: Forty years later, the expected number of deaths among a randomly
: selected demographically comparable group was ten, three from cancer.
: But among the 26 there were only four deaths, and just one from
: cancer. A small sample size to be sure, but hardly evidence of the
: most toxic substance known to man.
: This was at
: http://ans.neep.wisc.edu/~ans/point_source/AEI/may95/plutonium_eff.html
: Any more info on this anywhere?
I checked this site. It's a site run by the students in the nuclear
engineering school there. None of the material has any references, nor
does it seem to have been reviewed in any way. Don't believe everything
you read on a web page! There are similar web pages trumpeting cold
fusion, chiropractic cures, homeopathy, etc.
Michael Richmann
Post a cite Lloyd. Saying something's so doesn't make it so.
>
>:
>: Also, I found a bare-bones version of a story about 26 people who
>: accidentally ingested more than what is now deemed a "lethal" amount
>: of plutonium in the 1940s while working on the Manhattan Project, and
>: who were thereafter monitored by medical types with interest.
>: Forty years later, the expected number of deaths among a randomly
>: selected demographically comparable group was ten, three from cancer.
>: But among the 26 there were only four deaths, and just one from
>: cancer. A small sample size to be sure, but hardly evidence of the
>: most toxic substance known to man.
>: This was at
>: http://ans.neep.wisc.edu/~ans/point_source/AEI/may95/plutonium_eff.html
>: Any more info on this anywhere?
>
>I checked this site. It's a site run by the students in the nuclear
>engineering school there. None of the material has any references, nor
>does it seem to have been reviewed in any way. Don't believe everything
>you read on a web page! There are similar web pages trumpeting cold
>fusion, chiropractic cures, homeopathy, etc.
True enough. It is, however, a start and can be followed up upon and
verified. As for the toxicity characteristics of Pu, I agree with
Trosko's posting to a fair degree. I wouldn't be so upset if I happpened
to swallow the stuff (although our research indicates it'd probably do
a good job of putting the hurt on the bacteria in your gut) but inhalation
would very likely be a significant problem in the long term.
--
Mike
My opinions, not Argonne's...
Brian Trosko
Grinch <OldN...@mindspring.com> wrote:
: So really and truly, how toxic is plutonium?
Chemically, plutonium is a toxic heavy metal, like lead and arsenic. If
a small amount is ingested, you'll probably excrete it before it makes you
sick.
Radiologically, it's a fairly strong alpha emitter, which means it's
dangerous if it gets inside of you, but not too bad otherwise.
The hazards of Pu are defintely overstated. 26 workers on the Manhattan
project accidentally ingested quantities of plutonium larger than a lethal
dose. This is old data, but as of 1987, only four of these men had died
and only a single death was due to cancer. These rates are lower than the
statistical averages for the general population.
A good resource is
http://www.llnl.gov/csts/publications/sutcliffe/118825.html
And for the other person that posted: Yes, it's a web page. If you wish
to attack the credibility of Lawrence Livermore National Laboratories,
you'd better do your homework.
Henry Spencer
In article <5v82d6$2...@camel3.mindspring.com>,
Grinch <OldN...@mindspring.com> wrote:
> I've heard the line about "the most toxic substance known to man"
It's hysterical nonsense. Even if you optimize the details for maximum
effect, there are other substances which are considerably more toxic --
some of the bacterial toxins, for example. But telling the truth seldom
makes for good propaganda.
>...has calculated that ingesting a gram of plutonium
>increases radiation-related health risks only about as much as
>spending six months at 5,000 feet instead of sea level...
This is cheating a bit. Ingesting plutonium is a reasonably low-risk
thing to do, because it's not absorbed well (especially in the oxide
form used in the RTGs). The primary risk from plutonium is inhalation
of fine particles.
--
The operating systems of the 1950s will be out | Henry Spencer
next year from Microsoft. -- Mark Weiser | he...@zoo.toronto.edu
Matt Feinstein
> The primary risk from plutonium is inhalation
>of fine particles.
This is in line with what I've heard, that Pu is highly carcinogenic.
Don't know anything about how it accumulates biologically, which might
enhance or weaken the effect..
--
Matt Feinstein
mf...@aplcomm.jhuapl.edu
Organizational Department of Repeated
and Unnecessary Redundancy
DW
Matt Feinstein wrote:
>
> On Thu, 11 Sep 1997 14:41:51 GMT, Henry Spencer
> <he...@zoo.toronto.edu> wrote:
>
> > The primary risk from plutonium is inhalation
> >of fine particles.
>
> This is in line with what I've heard, that Pu is highly carcinogenic.
> Don't know anything about how it accumulates biologically, which might
> enhance or weaken the effect..
>
> --
> Matt Feinstein
I don't have all the details at hand, but my graduate research director
worked on Pu specific chelating agents for the removal of Pu from
mammals. We made compounds and tested them on rats and and beagles at
tracer levels. Prof. Ken Raymond (UC-Berkeley) has a series of papers
(mostly in JACS and IC) Specific Sequestering Agents for Actinides (I
believe there almost 30 articles in the series). In the introductions
they discuss the toxicity of Pu. First, you can break toxicity into
acute and chronic. As an acute toxin Pu is more toxic than stryctine
(sp? sorry I butchered that word) on a mg/kg basis. I will find the
number at home tonight but I remember something like 0.004 mg/kg was the
LD50 in rats (don't quote me on that just yet). But the Pu had to get
into the blood stream. In our test we injected the rats with
Pu(citrate) at tracer levels. Pu as the oxide does not cross the GI
tract so eating it is better than breathing it or sticking yourself with
a Pu contaminated pipet. Now for the chronic (radiological side). If
you get small amounts of Pu into your blood stream over time it will get
taken up in the Fe metabolic pathway and finally end up stored in your
bones. The body has no mechanism to get rid of Fe and hence Pu (except
bleeding) so more than 90% of the Pu that hits the blood stream will
stay in the body (some of our compounds were able to lower this to
20%). Overtime, this can lead to bone cancer. As stated before I don't
know of any case that can be linked 100% to Pu exposure as the cause of
death.
I will see if I can find the exact number for the LD50 tonight.
Donald
Ian Gay
In article <EGCyq...@midway.uchicago.edu>, me...@cars3.uchicago.edu wrote:
[snip]
>accumulation in the bones (plutonium chemistry is pretty similar to
>calcium,
What is your reason for saying that? Aqueous chemistry of Ca is essentially
that of Ca++, whereas I don't think Pu++ exists at all, and common species
like PuO2+ don't seem to me very Ca - like.
[snip]
*** To reply by e-mail, remove _nospam from address ***
Ken Tough
Brian Trosko <btr...@primenet.com> wrote:
>Chemically, plutonium is a toxic heavy metal, like lead and arsenic. If
>a small amount is ingested, you'll probably excrete it before it makes you
>sick.
>Radiologically, it's a fairly strong alpha emitter, which means it's
>dangerous if it gets inside of you, but not too bad otherwise.
>The hazards of Pu are defintely overstated. 26 workers on the Manhattan
>project accidentally ingested quantities of plutonium larger than a lethal
>dose. This is old data, but as of 1987, only four of these men had died
>and only a single death was due to cancer.
Its hazard depends on how it gets into you, though. If ingested,
as you say, it will likely pass through without too much harm.
The problem comes when it is inhaled as dust and gets trapped
inside your lungs. (As is the problem with asbestos).
--
Ken Tough Cornwall
k...@objectech.co.uk United Kingdom
me...@cars3.uchicago.edu
In article <5v9hgj$qrh$1...@morgoth.sfu.ca>, gay_n...@sfu.ca (Ian Gay) writes:
>In article <EGCyq...@midway.uchicago.edu>, me...@cars3.uchicago.edu wrote:
>[snip]
>>accumulation in the bones (plutonium chemistry is pretty similar to
>>calcium,
>
>What is your reason for saying that? Aqueous chemistry of Ca is essentially
>that of Ca++, whereas I don't think Pu++ exists at all, and common species
>like PuO2+ don't seem to me very Ca - like.
>
less Ca like Pu behaves, the less there is a chance of it accumulating
in the bones. So, in this sense the "Ca like" description represents
a worst case scenario.
Mati Meron | "When you argue with a fool,
me...@cars.uchicago.edu | chances are he is doing just the same"
Michael Richmann
gay_n...@sfu.ca (Ian Gay) wrote:
>In article <EGCyq...@midway.uchicago.edu>, me...@cars3.uchicago.edu wrote:
>[snip]
>>accumulation in the bones (plutonium chemistry is pretty similar to
>>calcium,
>
>What is your reason for saying that? Aqueous chemistry of Ca is essentially
>that of Ca++, whereas I don't think Pu++ exists at all, and common species
>like PuO2+ don't seem to me very Ca - like.
>
Plutonium has four possible oxidation states (+3,4,5,6). It wouldn't
be completely unreasonable in the body's attempt to dispose of it,
for it to be treated as a calcium like surrogate, given that it's not
that difficult to access any of the above listed states. One of the
key questions we've had to deal with in questions of plutonium disposal
is the interaction of biological entities with Pu and possible oxidation
state changes during that interaction.
Trish
I will add the following from "Basic Radiation Protection Technology"-
Gollnick;
"Plutonium is hazardous from three standpoints. It presents and
internal hazard from the alpha particle (energy of 5.1 Mev), it is a
pyrophoric which can spontaneously ignite when exposed to air and
there is a potential for criticality accidents."
"The physical half-life is 24,065 years while the biological and
effective half-life in bone is 200 years. Of the plutonium that
becomes dissolved in the blood, 90% normally will attach to the
skeletal system. Inhalation of Pu particles of about 1 micron in
diameter results in 25% reaching the lung."
Besides radium, I can't think of too many others I would certainly not
want to mess with.
DW
Ian Gay wrote:
>
> In article <EGCyq...@midway.uchicago.edu>, me...@cars3.uchicago.edu wrote:
> [snip]
> >accumulation in the bones (plutonium chemistry is pretty similar to
> >calcium,
>
> What is your reason for saying that? Aqueous chemistry of Ca is essentially
> that of Ca++, whereas I don't think Pu++ exists at all, and common species
> like PuO2+ don't seem to me very Ca - like.
>
> [snip]
>
The dominate oxidation state of Pu in the body is the 4+ state generally
bound to transferrin (the Fe transport protein). It is accumulated in
the bone though, since that is where we store Fe for blood cell
production.
Donald
.
me...@cars3.uchicago.edu
In article <3418328b.24419653@aplnews>, mf...@use.address.in.sig (Matt Feinstein) writes:
>On Thu, 11 Sep 1997 14:41:51 GMT, Henry Spencer
><he...@zoo.toronto.edu> wrote:
>
>> The primary risk from plutonium is inhalation
>>of fine particles.
>
>This is in line with what I've heard, that Pu is highly carcinogenic.
>Don't know anything about how it accumulates biologically, which might
>enhance or weaken the effect..
>
the lungs where it may get lodged and, over time, cause lung cancer.
However, the range of particulate sizes which may get permanently
lodged in, is rather small as I recall. The other risk is
only significant if the plutonium is present in the form of a water
soluble compound. Metalic plutonium is not readily assimilited.
With respect to both these risks plutonium is way less dangerous than,
say, radium, and way less than many other radioactive substances. The
claims of "most toxic substance known to mankind" are, to put it
mildly, plain bulshit (I can't prove it but I wouldn't be surprised if
rumours about the supposed horrible toxicity of plutonium were spread
by this or other branch of the defense establishment, in order to
discourage unauthorized personnel from attempting to get some of it).
The "usual" estimates of the toxicity of plutonium, are based on
nonsense of the sort of "if we finely subdivide it into grains of dust
of just the right size to cause lung cancer, then get these grains
into people lungs, one grain per person, that's how many people it can
kill. Well, based on such estimates, since one gram of conventional
explosive in the right spot can easily kill a person, we must conclude
that a one ton conventional bomb may kill million people, right?
me...@cars3.uchicago.edu
In article <depreej.29...@lincoln.ac.nz>, dep...@lincoln.ac.nz (Depree, Jonathan A) writes:
>
>In article <EGD22...@midway.uchicago.edu> me...@cars3.uchicago.edu writes:
>>From: me...@cars3.uchicago.edu
>>Subject: Re: Plutonium really the "most toxic poison known to man"?
>>Date: Thu, 11 Sep 1997 20:25:46 GMT
>>>>calcium,
>>>
>>>that of Ca++, whereas I don't think Pu++ exists at all, and common species
>>>like PuO2+ don't seem to me very Ca - like.
>>>
>>less Ca like Pu behaves, the less there is a chance of it accumulating
>>in the bones. So, in this sense the "Ca like" description represents
>>a worst case scenario.
>
>calcium in the body.
Strontium does. And so does radium. But, no, I wan't thinking of
either. Anyway, in the meantime it has been posted that Pu chemistry
in the body is closer to this of iron. With the net effect still
being the same, i.e. bone accumulation. But, the solubility is very
low.
Brooks Moses
Timothy P. Corbett wrote:
>
> In article <T80j0GAv...@dial.pipex.com>,
> Ken Tough <k...@objectech.co.uk> wrote:
>
> >Its hazard depends on how it gets into you, though. If ingested,
> >as you say, it will likely pass through without too much harm.
> >The problem comes when it is inhaled as dust and gets trapped
> >inside your lungs.
>
> heavy metal. And if it were dust, what manner of conveyence
> would transport it into the lungs of large numbers of people?
If Ken were to take a small quantity of plutonium, and make it into
powder by some excessively easy way, and then sprinkle it over your
house, it _would_ be dust and you would probably inhale some of it.
Admittedly it would take a good bit of plutonium to sprinkle a large
city, but it could be done fairly easily in a crowded market area --
fill a nuke-capable bomber with a few just sub-critical piles of
powderized plutonium, fly in low over downtown X-ville's city market,
and let loose. The piles of powder descend as dust into the crowds, and
the rest is history.
Per your H20 counter-example, it's rather hard to powderize water so
that people inhale enough to fill their lungs, but a little powderized
Pu would be easy and disastrous....
Richard A. Schumacher
>I will add the following from "Basic Radiation Protection Technology"-
>Gollnick;
>"Plutonium is hazardous from three standpoints. It presents and
>internal hazard from the alpha particle (energy of 5.1 Mev), it is a
>pyrophoric which can spontaneously ignite when exposed to air and
>there is a potential for criticality accidents."
>"The physical half-life is 24,065 years while the biological and
>effective half-life in bone is 200 years. Of the plutonium that
>becomes dissolved in the blood, 90% normally will attach to the
>skeletal system. Inhalation of Pu particles of about 1 micron in
>diameter results in 25% reaching the lung."
Which is why no one should be concerned about Cassini crashing.
All the plutonium is in oxide form, so it won't burn. As long
as one does not (a) use an acetylene torch to vaporize the RTG
and inhale the vapor, or (b) eat the RTG, there is no risk. There's
no other way to get any of that moderately dangerous plutonium into
one's body.
Anyone who smokes or drives a car or eats cooked meat or sunbathes
and yet worries about Cassini is either ignorant or an idiot.
--
FCC: Chairman Reed Hundt: rhu...@fcc.gov Commissioner James Quello:
jqu...@fcc.gov Commissioner Susan Ness: sn...@fcc.gov Commissioner
Rachelle Chong: rch...@fcc.gov
Larks
Grinch wrote:
>
====== Stuff Purged =======
> So really and truly, how toxic is plutonium?
Well, the maximum body burden for Pu-239 is about
0.6 ug, while that of Po-210, is about 0.0000068 ug.
(source, CRC of Chem/Phys)
One could certainly argue that Po-210 is about
100,000 times as "toxic" as Pu-239.
I suppose as a first estimate, one could calculate
that with Pu-239 having a body burden of 0.6 ug,
a sample of Pu-238 having the same activity
would be
(0.6 ug)(86 yrs/24400 yrs) = 0.002 ug
.. where I've ignored the 0.5% mass difference between
the two Pu isotopes ...
Again, a first estimate only, but a far cry from the
permissible body burden of Po. I cannot find the
permissible body burden of Pu-238 in literature
anywhere.
It's interesting that The Gunniess Book of World
Records for many years listed (and perhaps still lists)
Pu as the "most poisonous element".
Patrick Draper
> True enough. It is, however, a start and can be followed up upon and
> verified. As for the toxicity characteristics of Pu, I agree with
> Trosko's posting to a fair degree. I wouldn't be so upset if I happpened
> to swallow the stuff (although our research indicates it'd probably do
> a good job of putting the hurt on the bacteria in your gut) but inhalation
> would very likely be a significant problem in the long term.
Inhalation is very unlikely because the form of the plutonium is like
a ceramic (in the case of the Cassini spacecraft). Destruction of the
plutonium due to an impace would result in large broken pieces, not
a fine powder.
Patrick
Tim Gillespie
Timothy P. Corbett wrote:
>
> In article <T80j0GAv...@dial.pipex.com>,
> Ken Tough <k...@objectech.co.uk> wrote:
>
> >Its hazard depends on how it gets into you, though. If ingested,
> >as you say, it will likely pass through without too much harm.
> >The problem comes when it is inhaled as dust and gets trapped
> >inside your lungs.
>
> But that's precisely the point. Pu is *not* dust, it's a
> heavy metal. And if it were dust, what manner of conveyence
> would transport it into the lungs of large numbers of people?
>
> a relatively small quantity could kill every person on the planet
> if it gets trapped inside their lungs.
>
This reminds me of the little known buy deadly chemical DHMO, The
Invisible Killer:
Dihydrogen monoxide (DHMO) is colorless, odorless, tasteless, and kills
uncounted thousands of people every year. Most of these deaths are
caused by accidental inhalation of DHMO, but the dangers of dihydrogen
monoxide do not end there. Prolonged exposure to its solid form causes
severe tissue damage. Symptoms of DHMO ingestion can include excessive
sweating and urination, and possibly a bloated feeling, nausea, vomiting
and body electrolyte imbalance. For those who have become dependent,
DHMO withdrawal means certain death.
Dihydrogen monoxide:
- is also known as hydroxyl acid, and is the major component of acid
rain.
- contributes to the "greenhouse effect."
- may cause severe burns.
- contributes to the erosion of our natural landscape.
- accelerates corrosion and rusting of many metals.
- may cause electrical failures and decreased effectiveness of
automobile brakes.
- has been found in excised tumors of terminal cancer patients.
Contamination Is Reaching Epidemic Proportions!
Quantities of dihydrogen monoxide have been found in almost every
stream, lake, and reservoir in America today. But the pollution is
global, and the contaminant has
even been found in Antarctic ice. DHMO has caused millions of dollars of
property damage in the midwest, and recently California.
Despite the danger, dihydrogen monoxide is often used:
- as an industrial solvent and coolant.
- in nuclear power plants.
- in the production of styrofoam.
- as a fire retardant.
- in many forms of cruel animal research.
- in the distribution of pesticides. Even after washing, produce remains
contaminated by this chemical.
- as an additive in certain "junk-foods" and other food products.
Companies dump waste DHMO into rivers and the ocean, and nothing can be
done to stop them because this practice is still legal. The impact on
wildlife is extreme,
and we cannot afford to ignore it any longer!
The Horror Must Be Stopped!
The American government has refused to ban the production, distribution,
or use of this damaging chemical due to its "importance to the economic
health of this
nation." In fact, the navy and other military organizations are
conducting experiments with DHMO, and designing multi-billion dollar
devices to control and utilize it during warfare situations. Hundreds of
military research facilities receive tons of it through a highly
sophisticated underground distribution network. Many store large
quantities for later use.
:-)
--
___ _____
Tim .'/,-Y" "~-.
Gillespie l.Y ^.
/\ _\_
i ___/" "\
| /" "\ o !
l ] o !__./
\ _ _ \.___./ "~\
X \/ \ ___./
( \ ___. _..--~~" ~`-.
` Z,-- / \
\__. ( / ______)
\ l /-----~~" /
Y \ /
| "x______.^
| \
j Y
Doug Bell
Grinch wrote:
>
> With NASA getting ready to launch the Cassini Saturn probe, loaded
> with plutonium in lieu of Everready batteries, we're hearing a lot of
> scare scenarios about what could happen if the rocket blows up --
> colorful images along the lines of "a fine dust of plutonium
> descending from a burnt-up spacecraft to make a good chunk of Florida
> uninhabitable for 12,000 generations", which was just presented in a
> NYC newspaper.
>
>
survived a re-entry from escape velocity with (to the best of my
knowledge) no observable effects. Certainly no catastrophe. It should
also be noted that even very spectacular rocket disasters produce
relativly little damage to the major components. I'm talking about the
Vanguard on display in the Smithsonian, and the fact that even the
Challenger maintained enough structural integrity to preserve
identifiable human bodies. Not the kind of thing which destroys
containers meant to survive intact, let alone powder the ceramics inside
those containers.
Clear skies,
Doug
--
Doug Bell If you can't see the stars, then your
doug...@navix.net community is wasting money on poorly
Lincoln Nebraska designed outdoor lighting.
Larks
Greg Hartman wrote:
>
> Interesting that folks are panicking about Cassini when we';ve already
> launched at least one probe with nuclear material on it--Vaoyager, to be
> exact.
I assume that the later (meaning late in the program)
Pioneer series were also carrying Pu. Pioneer 10, 11?
I really don't know what their energy sources were, but I would
assume Pu or Pr.
These spacecraft were launched a generation ago.
======= remainder purged ======
Greg Hartman
Interesting that folks are panicking about Cassini when we';ve already
launched at least one probe with nuclear material on it--Vaoyager, to be
exact.
I remember when it passed Neptune; several magazines ran daigrams of it
and wowed and gosh wollickered over its amazingly tiny computer.
And they mentioned that it's powered by an small atomic battery,
something I DON'T remember anyone telling us back in '77 when it first
went up.
--
Christian Humor!
http://christianhumor.miningco.com
"Do We Have To Give Up Our Brains For Jesus?"
http://www.aracnet.com/~ghartman/index.shtml
(Return address modified to block unsolicited commercial e-mail; remove
"nospam")
Depree, Jonathan A
In article <EGD22...@midway.uchicago.edu> me...@cars3.uchicago.edu writes:
>From: me...@cars3.uchicago.edu
>Subject: Re: Plutonium really the "most toxic poison known to man"?
>Date: Thu, 11 Sep 1997 20:25:46 GMT
>In article <5v9hgj$qrh$1...@morgoth.sfu.ca>, gay_n...@sfu.ca (Ian Gay) writes:
>>In article <EGCyq...@midway.uchicago.edu>, me...@cars3.uchicago.edu wrote:
>>[snip]
>>>accumulation in the bones (plutonium chemistry is pretty similar to
>>>calcium,
>>
>>What is your reason for saying that? Aqueous chemistry of Ca is essentially
>>that of Ca++, whereas I don't think Pu++ exists at all, and common species
>>like PuO2+ don't seem to me very Ca - like.
>>
>Oh, I'm just repeating what somebody posted here once. Mind you, the
>less Ca like Pu behaves, the less there is a chance of it accumulating
>in the bones. So, in this sense the "Ca like" description represents
>a worst case scenario.
You're not thinking of strontium are you? That definitely does behave like
calcium in the body.
Jonathan Depree,
Lincoln University, P.O. Box 84, Canterbury, New Zealand.
Socrates was a famous Greek Teacher who went around giving
people advice. They killed him. (school history howler)
Ian Gay
In article <EGD22...@midway.uchicago.edu>, me...@cars3.uchicago.edu wrote:
>In article <5v9hgj$qrh$1...@morgoth.sfu.ca>, gay_n...@sfu.ca (Ian Gay) writes:
>>In article <EGCyq...@midway.uchicago.edu>, me...@cars3.uchicago.edu wrote:
>>[snip]
>>>accumulation in the bones (plutonium chemistry is pretty similar to
>>>calcium,
>>
>>What is your reason for saying that? Aqueous chemistry of Ca is essentially
>>that of Ca++, whereas I don't think Pu++ exists at all, and common species
>>like PuO2+ don't seem to me very Ca - like.
>>
>Oh, I'm just repeating what somebody posted here once. Mind you, the
>less Ca like Pu behaves, the less there is a chance of it accumulating
>in the bones. So, in this sense the "Ca like" description represents
>a worst case scenario.
>
Maybe they were all mixed up with Sr fission products?
Jim Carr
gay_n...@sfu.ca (Ian Gay) writes:
}me...@cars3.uchicago.edu wrote:
}>Oh, I'm just repeating what somebody posted here once. Mind you, the
}>less Ca like Pu behaves, the less there is a chance of it accumulating
}>in the bones. So, in this sense the "Ca like" description represents
}>a worst case scenario.
}
}Maybe they were all mixed up with Sr fission products?
The confusion is about the mechanism that puts it in the bones,
since Pu (like Radium) does end up in the bones and the allowed
Ra burden -- established with high statistics data -- did serve
as the reference point for Pu rad safety until more was learned
(specifically that Pu is 5 times more likely than Ra to get to
the bones based on an article in Los Alamos Science).
--
James A. Carr <j...@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.
Timothy P. Corbett
>Its hazard depends on how it gets into you, though. If ingested,
>as you say, it will likely pass through without too much harm.
>The problem comes when it is inhaled as dust and gets trapped
>inside your lungs.
But that's precisely the point. Pu is *not* dust, it's a
heavy metal. And if it were dust, what manner of conveyence
would transport it into the lungs of large numbers of people?
This line of argument is like saying water is very deadly because
a relatively small quantity could kill every person on the planet
if it gets trapped inside their lungs.
Cheers,
Tim
me...@cars3.uchicago.edu
In article <5v9v2l$h...@flare.convex.com>, schu...@convex.com (Richard A. Schumacher) writes:
>>
>>I will add the following from "Basic Radiation Protection Technology"-
>>Gollnick;
>
>>"Plutonium is hazardous from three standpoints. It presents and
>>internal hazard from the alpha particle (energy of 5.1 Mev), it is a
>>pyrophoric which can spontaneously ignite when exposed to air and
>>there is a potential for criticality accidents."
>
>>"The physical half-life is 24,065 years while the biological and
>>effective half-life in bone is 200 years. Of the plutonium that
>>becomes dissolved in the blood, 90% normally will attach to the
>>skeletal system. Inhalation of Pu particles of about 1 micron in
>>diameter results in 25% reaching the lung."
>
>Which is why no one should be concerned about Cassini crashing.
>All the plutonium is in oxide form, so it won't burn. As long
>as one does not (a) use an acetylene torch to vaporize the RTG
>and inhale the vapor, or (b) eat the RTG, there is no risk. There's
>no other way to get any of that moderately dangerous plutonium into
>one's body.
>
>Anyone who smokes or drives a car or eats cooked meat or sunbathes
>and yet worries about Cassini is either ignorant or an idiot.
Mind you, these two options are not mutually exclusive :-)
me...@cars3.uchicago.edu
In article <341890...@stanford.edu>, Brooks Moses <bmo...@stanford.edu> writes:
>Timothy P. Corbett wrote:
>>
>> In article <T80j0GAv...@dial.pipex.com>,
>> Ken Tough <k...@objectech.co.uk> wrote:
>>
>> >Its hazard depends on how it gets into you, though. If ingested,
>> >as you say, it will likely pass through without too much harm.
>> >The problem comes when it is inhaled as dust and gets trapped
>> >inside your lungs.
>>
>> But that's precisely the point. Pu is *not* dust, it's a
>> heavy metal. And if it were dust, what manner of conveyence
>> would transport it into the lungs of large numbers of people?
>
>powder by some excessively easy way, and then sprinkle it over your
>house, it _would_ be dust and you would probably inhale some of it.
>Admittedly it would take a good bit of plutonium to sprinkle a large
>city, but it could be done fairly easily in a crowded market area --
>fill a nuke-capable bomber with a few just sub-critical piles of
>powderized plutonium, fly in low over downtown X-ville's city market,
>and let loose. The piles of powder descend as dust into the crowds, and
>the rest is history.
The rest is history? In what sense? As a military weapon? Using a
weapon which kills your opponents within 20-30 years is hardly
advantageous, from a military point of view. In fact it is about as
stupid as it gets.
Frank Crary
In article <5v82d6$2...@camel3.mindspring.com>,
Grinch <OldN...@mindspring.com> wrote:
> With NASA getting ready to launch the Cassini Saturn probe, loaded
>with plutonium in lieu of Everready batteries, we're hearing a lot of
>scare scenarios about what could happen if the rocket blows up --
>colorful images along the lines of "a fine dust of plutonium
>descending from a burnt-up spacecraft to make a good chunk of Florida
>uninhabitable for 12,000 generations", which was just presented in a
>NYC newspaper.
This claim is absurd. The half life of plutonium 238 (the isotope in
question) is 86 years. Assuming a generation is 20 years, then, ahh...
I can't say exactly how little will be left after 12,000 generations.
Xcalc gives me zero, which means it's less than 16 bit floating point
precision can calculate. Put another way, all but one part in a million
would be gone after 1188 years or 60 generations.
The description of ``a find dust of plutonium'' is also false. In the
late 1960s, an RTG was on a rocket which exploded. Not only was no
plutonium released, but the RTG was intact and was simply inspected,
attached to the replacement spacecraft, and launched. Even if the
RTG on Cassini were damaged, there is essentially zero chance that
it would produce a ``fine dust of plutonium''. Large chunks of plutonium
are far more likely.
> I've heard the line about "the most toxic substance known to man"
>countless times, but when I tried to look into it on the Web I found
>the research of Dr. Bernard Cohen, a physics professor at the
>University of Pittsburgh and former president of the Health Physics
>Society, who has calculated that ingesting a gram of plutonium
>increases radiation-related health risks only about as much as
>spending six months at 5,000 feet instead of sea level; say, in Denver
>instead of New York.
> Apparently Dr. Cohen has publicly offered to eat as much plutonium
>as Ralph Nader would eat pure caffeine, saying the health risk is
>comparable, but so far Mr. Nader has declined.
> Also, I found a bare-bones version of a story about 26 people who
>accidentally ingested more than what is now deemed a "lethal" amount
>of plutonium in the 1940s while working on the Manhattan Project, and
>who were thereafter monitored by medical types with interest.
> Forty years later, the expected number of deaths among a randomly
>selected demographically comparable group was ten, three from cancer.
>But among the 26 there were only four deaths, and just one from
>cancer. A small sample size to be sure, but hardly evidence of the
>most toxic substance known to man.
>All this is an *awful* long way from plutonium's "most toxic
>substance" reputation, even by the standards of urban legends.
>So really and truly, how toxic is plutonium?
Well, the real answer is that it depends, but in any case it is not
the most toxic substance known to man. It depends because plutonium
is a fairly mild alpha emitter. Alpha particles are easily stopped
by almost anything. The danger comes from getting it in contact
with one's body and keeping it in contact for a long time (i.e.
years). If that happens, some form of cancer is likely, even if
only a small amount of plutonium is involved. Getting it on your
skin isn't dangerous, since most people bathe more often than once
every few years. Plutonium dioxide (the chemical form used in RTGs)
is not soluble in water. So swallowing the stuff isn't especially
dangerous: It just passes through your system in a few days (this
is probably the basis for the above estimates that it isn't all that
dangerous.) Inhaling large particles of it isn't dangerous either.
The lungs have several mechanisms for removing inhaled dust, typically
in less than a month. However, these mechanisms aren't good at removing
very small particles. Below about three microns in size, particles
that get into the lungs stay there. So inhaling a very small amount
of micron or submicron plutonium dust is likely to result in lung
cancer after a few decades. For that particular type of exposure,
plutonium is very, very dangerous. However, the idea that a launch
accident, or reentery of the spacecraft during the Earth gravity assist,
could produce a significant quantity of such extremely fine particles,
is a joke. RTGs have survived launch failures and reentries without
releasing any plutonium (including the RTG on the Apollo 13 lunar
module, which occurred at velocities similar to that of the Cassini
gravity assist.) Nor would release of plutonium magically turn it
into extremely small particles. Plutonium dioxide can't burn, and
doesn't vaporize at even the high temperatures of reentry. Basically,
we are talking about smashing it up by physical force. Plutonium
dioxide is a ceramic, as a coffee mug. Just try setting a coffee
mug on fire (hint, you can't) or getting it hot enough to even melt.
Go to alot of effort pounding one up, and see what fraction of the
debris is so small you can't see it without a microscope.
Even in the form of inhaled, extremely small particles, plutonium
isn't the most deadly substance known to man. The CRC Handbook of
Physics and Chemistry lists acceptable exposure levels to various
radioactive substances. I happened to look up the level for inhaled
plutonium today. It's 0.022 micro Curies, if you care. Most of the
other entries on the page (also for inhaled particles) were much
lower. I.e. out of a page full of radioactives, most were more deadly
than plutonium 238.
Frank Crary
CU Boulder
Wm James
:
: With NASA getting ready to launch the Cassini Saturn probe, loaded
:with plutonium in lieu of Everready batteries, we're hearing a lot of
:scare scenarios about what could happen if the rocket blows up --
:colorful images along the lines of "a fine dust of plutonium
:descending from a burnt-up spacecraft to make a good chunk of Florida
:uninhabitable for 12,000 generations", which was just presented in a
:NYC newspaper.
The crime rate has already done that.
William R. James
Gavin Whittaker
Richard A. Schumacher (schu...@convex.com) wrote:
: Anyone who smokes or drives a car or eats cooked meat or sunbathes
: and yet worries about Cassini is either ignorant or an idiot.
No. There are some risks which people are prepared to take, given
the pleasure they get from the activity. There are some risks which are
needlessly imposed on them that they don't like.
Because *you* may be prepared to take the risk does not automatically
give you the right to impose it on others. Objecting to the imposed risk
does not automatically qualify a person as 'either ignorant or an idiot'.
Gavin
*****************************************************************************
Dr. A.G. Whittaker - Dept. of Chemistry, King's buildings, West Mains
Rd., Edinburgh. EH9 3JJ.
Tel: 0131 6504800. Fax: 0131 6504743.
email: ah...@festival.ed.ac.uk
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
In any organisation, there are those who can manage, and those who
can't manage. Then there are those who can't quite manage. These
are the middle managers.
'Office Politics', The Guardian.
*****************************************************************************
Hactar
In article <5v8vp2$4...@milo.mcs.anl.gov>,
Michael Richmann <rich...@cmt.anl.gov> wrote:
>lpa...@curly.cc.emory.edu (Lloyd R. Parker) wrote:
>>Grinch (OldN...@mindspring.com) wrote:
>>:
>>: Most of the discussion is about the risk of accident to the
>>: spacecraft, but I'm more curious about the real toxicity of plutonium.
>>:
>>The chemical toxicity of plutonium alone is enough to label anybody who
>>says he would ingest it as a bona fide nut case.
>
>Post a cite Lloyd. Saying something's so doesn't make it so.
How about the CRC Handbook of Chemistry and Physics, 70th Ed.
(1989-1990), ISBN 0-8493-0470-9 (?), p. B-29:
<begin quote>
Because of the high rate of emission of alpha particles and the
element being specifically absorbed by bone marrow, plutonium, as well
as all of the other transuranium elements except neptunium, are
radiological poisons and must be handled with very special equipment
and precautions. Plutonium is a very dangerous radiological hazard.
<end quote>
Doesn't give any hard data regarding toxicity.
--
Headers encoded; / An idea that is not dangerous is unworthy
un-rot13 to mail / of being called an idea at all. Oscar Wilde
He who will not reason is a bigot; he who cannot is a fool;
and he who dares not is a slave. Sir William Drummond
Mark Adler
In article <5v8rer$5...@curly.cc.emory.edu>,
Lloyd R. Parker <lpa...@curly.cc.emory.edu> wrote:
>The chemical toxicity of plutonium alone is enough to label anybody who
>says he would ingest it as a bona fide nut case.
He wasn't talking about Pu metal, he was talking about plutonium dioxide,
which is not chemically toxic. If you've ever had a barium shake, you
can guess how the stuff would come out the other end. :-)
mark
Ken Tough
"Richard A. Schumacher" <schu...@convex.com> wrote:
>Which is why no one should be concerned about Cassini crashing.
>All the plutonium is in oxide form, so it won't burn. As long
>as one does not (a) use an acetylene torch to vaporize the RTG
>and inhale the vapor, or (b) eat the RTG, there is no risk. There's
>no other way to get any of that moderately dangerous plutonium into
>one's body.
>Anyone who smokes or drives a car or eats cooked meat or sunbathes
>and yet worries about Cassini is either ignorant or an idiot.
I can't say as I'm particularly worried about Cassini, but at
what quantities would it become a bad thing? How about disposing
of nuclear waste that way?
By the way, I think an acetylene torch doesn't hold a candle
to an interplanetary launch vehicle. :)
(Not that that makes it any more likely to produce plutonium dust,
as people have posted. I recall a SciAmerican article about a
nuclear reprocessing plant being decommissioned in the US, which
has hundreds of kilos (?) of plutonium dust in its air ducts &
crannies. Now that's a bit more worrying.)
--
Ken Tough
Steinn Sigurdsson
ah...@holyrood.ed.ac.uk (Gavin Whittaker) writes:
> Richard A. Schumacher (schu...@convex.com) wrote:
> : Anyone who smokes or drives a car or eats cooked meat or sunbathes
> : and yet worries about Cassini is either ignorant or an idiot.
> No. There are some risks which people are prepared to take, given
> the pleasure they get from the activity. There are some risks which are
> needlessly imposed on them that they don't like.
> Because *you* may be prepared to take the risk does not automatically
> give you the right to impose it on others. Objecting to the imposed risk
> does not automatically qualify a person as 'either ignorant or an idiot'.
But when someone else smokes, drives or cooks meat they
expose third parties to risk (me specifically).
Hence they do impose risk on others, and assume they
have the right to do so.
Question is why they think the risk of Cassini to them
(which is negligibly small IMAO) should be objected to
while other risks are ignored, and why they ignore the
benefit I perceive I get from Cassini in making their
decision to object.
Patrick Reid
[Posted to sci.energy]
lpa...@curly.cc.emory.edu (Lloyd R. Parker) wrote:
>I checked this site. It's a site run by the students in the nuclear
>engineering school there. None of the material has any references, nor
>does it seem to have been reviewed in any way. Don't believe everything
>you read on a web page! There are similar web pages trumpeting cold
>fusion, chiropractic cures, homeopathy, etc.
Mr. Parker, you have been provided with a reference to two articles in
peer-reviewed journals regarding the exposure of A-bomb workers to Pu.
Why haven't you checked out the reference?
By the way, the site you are referring to:
http://ans.neep.wisc.edu/~ans/point_source/AEI/may95/plutonium_eff.html
Is the site for Atomic Energy Insights, which is run by Rod Adams, a
former nuclear sub navy guy. Not a student.
Patrick Reid (pjr...@nbnet.nb.ca)
ALARA Research, Incorporated
Saint John, NB, Canada
http://personal.nbnet.nb.ca/pjreid
Trish
On 11 Sep 1997 18:32:37 -0500, schu...@convex.com (Richard A.
Schumacher) wrote:
>
>
>
>>I will add the following from "Basic Radiation Protection Technology"-
>>Gollnick;
>
>>"Plutonium is hazardous from three standpoints. It presents and
>>internal hazard from the alpha particle (energy of 5.1 Mev), it is a
>>pyrophoric which can spontaneously ignite when exposed to air and
>>there is a potential for criticality accidents."
>
>>"The physical half-life is 24,065 years while the biological and
>>effective half-life in bone is 200 years. Of the plutonium that
>>becomes dissolved in the blood, 90% normally will attach to the
>>skeletal system. Inhalation of Pu particles of about 1 micron in
>>diameter results in 25% reaching the lung."
>
>
>
>Which is why no one should be concerned about Cassini crashing.
>All the plutonium is in oxide form, so it won't burn. As long
>as one does not (a) use an acetylene torch to vaporize the RTG
>and inhale the vapor, or (b) eat the RTG, there is no risk. There's
>no other way to get any of that moderately dangerous plutonium into
>one's body.
>
>Anyone who smokes or drives a car or eats cooked meat or sunbathes
>and yet worries about Cassini is either ignorant or an idiot.
>
I admit to not reading all of the posts on this particular thread. I
was under the assumption (yeah I know, I know) that it was a thread
regarding what was presumed to be "the most hazardous" etc... I don't
know anything about Cassini so I guess according to you that makes me
ignorant. Gosh, am I supposed to curl up and quit posting now that
you have made this declaration? Get over yourself
Michael Richmann
I was talking about plutonium hazards in general, not the Cassini case
specifically. Read for context, not just content. BTW, if you're going
to both e-mail and post, etiquette dictates you inform the recipient to
avoid duplicate posting/e-mailing.
--
Mike
My opinions, not Argonne's...
Lloyd R. Parker
me...@cars3.uchicago.edu wrote:
: With respect to both these risks plutonium is way less dangerous than,
: say, radium, and way less than many other radioactive substances.
Totally, utterly false.
: The
: claims of "most toxic substance known to mankind" are, to put it
: mildly, plain bulshit (I can't prove it but I wouldn't be surprised if
So it's just your opinion. Well, gee whiz, I can't prove the earth is
flat either. Can I claim that?
: rumours about the supposed horrible toxicity of plutonium were spread
: by this or other branch of the defense establishment, in order to
: discourage unauthorized personnel from attempting to get some of it).
Conspiracy alert! Conspiracy alert! Call in Mulder and Scully.
Michael Pelletier
In article <341890...@stanford.edu>,
Brooks Moses <bmo...@stanford.edu> wrote:
>If Ken were to take a small quantity of plutonium, and make it into
>powder by some excessively easy way, and then sprinkle it over your
>house, it _would_ be dust and you would probably inhale some of it.
>Admittedly it would take a good bit of plutonium to sprinkle a large
>city, but it could be done fairly easily in a crowded market area --
>fill a nuke-capable bomber with a few just sub-critical piles of
>powderized plutonium, fly in low over downtown X-ville's city market,
>and let loose. The piles of powder descend as dust into the crowds, and
>the rest is history.
>
>that people inhale enough to fill their lungs, but a little powderized
>Pu would be easy and disastrous....
If you call a miniscule rise in the number of lung tumors detected
in the community decades later and a few acutely sick people who
were hit by clumps of powder, a "disaster," then sure. I don't
suppose it would be a disaster for the thoracic surgeons in the
area, though, when they'd be finally able to buy that BMW they'd
been eyeing after removing a few extra tumors.
Far more effective would be to sprinkle cobalt-60 dust obtained from
a local hospital. It's a far hotter, far more dangerous radiation
source than plutonium, being a strong gamma-emitter. Even more
effective would be to culture some salmonella or botulism from your
kitchen counter or an old can, and sprinkle that. Or grind up some
arsenic, sprinkle cyanide, contaminate the water supply with
methyl-mercury, disperse some sarin gas, or any number of other
approaches. These would produce far far more immediate deaths
than plutonium powder.
And besides, plutonium dust has already been scattered to the winds
in vast quantities by atomic bomb tests. A ridiculously conservative
estimate is 2.5 metric tons -- based on the minimum of 10kg of
plutonium for a bomb, 516 atmospheric bomb tests, and a bomb burn-up
of 50% -- and I've seen estimates as high as 11 tonnes.
-Mike Pelletier.
Lloyd R. Parker
Larks ("La...@worldnet.att.net"@worldnet.att.net) wrote:
: Again, a first estimate only, but a far cry from the
: permissible body burden of Po. I cannot find the
: permissible body burden of Pu-238 in literature
: anywhere.
:
: It's interesting that The Gunniess Book of World
: Records for many years listed (and perhaps still lists)
: Pu as the "most poisonous element".
Merck says, max. permissable level of Pu239 in air, 6 X 10(-13) uCi/cc.
For Po210, 7 X 10(-11) uCi/cc. This would say Pu239 is 100 times more
toxic when in air.
Lloyd R. Parker
Timothy P. Corbett (ti...@mailhost2.planet.net) wrote:
:
: But that's precisely the point. Pu is *not* dust, it's a
: would transport it into the lungs of large numbers of people?
A bomb. Dispersal from a plane. Combustion of the metal. Surely you can
imagine a terrorist group, or a nation like Libya, giving serious
consideration to such action.
Drew Davis
In article <3428ce75...@nntp.a001.sprintmail.com>,
Wm James <sp...@here.not> wrote:
>On Thu, 11 Sep 1997 06:16:54 GMT, OldN...@mindspring.com
>(Grinch) wrote:
>:colorful images along the lines of "a fine dust of plutonium
>:descending from a burnt-up spacecraft to make a good chunk of Florida
>:uninhabitable for 12,000 generations
>The crime rate has already done that.
Yeah, but that's due to an entirely different sort of fine dust.
--
L. Drew Davis dr...@nortel.ca
You might very well think that; I couldn't possibly comment.
Lloyd R. Parker
Frank Crary (fcr...@rintintin.Colorado.EDU) wrote:
:
: This claim is absurd. The half life of plutonium 238 (the isotope in
: question) is 86 years. Assuming a generation is 20 years, then, ahh...
: I can't say exactly how little will be left after 12,000 generations.
: Xcalc gives me zero, which means it's less than 16 bit floating point
: precision can calculate. Put another way, all but one part in a million
: would be gone after 1188 years or 60 generations.
Depends on how much you start with -- A(sub)0, remember? Further, you
need to consider its decay products, most of which are also radioactive.
: it would produce a ``fine dust of plutonium''. Large chunks of plutonium
: are far more likely.
Now you're an expert on combustions and explosions? Or is this just what
the nuclear industry has said?
:
: Well, the real answer is that it depends, but in any case it is not
: the most toxic substance known to man. It depends because plutonium
: is a fairly mild alpha emitter.
This is like saying something is a "fairly mild strain of Ebola."
: Alpha particles are easily stopped
: by almost anything.
Including body tissues, which is where the danger comes in.
: The danger comes from getting it in contact
: with one's body and keeping it in contact for a long time (i.e.
: years). If that happens, some form of cancer is likely, even if
: only a small amount of plutonium is involved. Getting it on your
: skin isn't dangerous, since most people bathe more often than once
: every few years. Plutonium dioxide (the chemical form used in RTGs)
: is not soluble in water.
What happens when plutonium oxide encounters HCl?
: Even in the form of inhaled, extremely small particles, plutonium
: isn't the most deadly substance known to man. The CRC Handbook of
: Physics and Chemistry lists acceptable exposure levels to various
: radioactive substances. I happened to look up the level for inhaled
: plutonium today. It's 0.022 micro Curies, if you care. Most of the
: other entries on the page (also for inhaled particles) were much
: lower. I.e. out of a page full of radioactives, most were more deadly
: than plutonium 238.
According to Merck, the maxiumum permissable level of Pu238 in air is 7 X
10(-13) uCi/cc. The maximum lifetime inhalation level is 0.2 ug.
Lloyd R. Parker
: as one does not (a) use an acetylene torch to vaporize the RTG
: and inhale the vapor, or (b) eat the RTG, there is no risk. There's
: no other way to get any of that moderately dangerous plutonium into
: one's body.
Gee, you don't think there's a chance the spacecraft could blow up (e.g.,
Challenger)? Or that an explosion and fire from a crash could vaporize
the material?
Jim Meritt
In article <5v82d6$2...@camel3.mindspring.com>, OldN...@mindspring.com
says...
> I've heard the line about "the most toxic substance known to man"
>countless times, but when I tried to look into it on the Web I found
>the research of Dr. Bernard Cohen, a physics professor at the
>University of Pittsburgh and former president of the Health Physics
>Society, who has calculated that ingesting a gram of plutonium
>increases radiation-related health risks only about as much as
>spending six months at 5,000 feet instead of sea level; say, in Denver
>instead of New York.
Not eat - breath. One dust-sized particle inhaled into the lungs could cause
lung cancer. Stuff is an alpha emitter - skin is a fine shield. I've seen
pictures of a cubic inch or so held in a hand.
Chemical toxicity? Bet titanium is a lot worse...
--
James W. Meritt
The opinions expressed above are my own. The facts simply
are and belong to none.
Michael Richmann
lpa...@larry.cc.emory.edu (Lloyd R. Parker) wrote:
>Frank Crary (fcr...@rintintin.Colorado.EDU) wrote:
>:
>: This claim is absurd. The half life of plutonium 238 (the isotope in
>: question) is 86 years. Assuming a generation is 20 years, then, ahh...
>: I can't say exactly how little will be left after 12,000 generations.
>: Xcalc gives me zero, which means it's less than 16 bit floating point
>: precision can calculate. Put another way, all but one part in a million
>: would be gone after 1188 years or 60 generations.
>
>need to consider its decay products, most of which are also radioactive.
He was talking about ppm, not absolute amounts. You've been beaten
about the head and shoulders over this sort of thing in the "nuclear
fule" thread and really ought to know better. As a general rule of
thumb, an isotope is considered to have decayed away after approx.
30 half-lives.
>
>: it would produce a ``fine dust of plutonium''. Large chunks of plutonium
>: are far more likely.
>
>Now you're an expert on combustions and explosions? Or is this just what
>the nuclear industry has said?
Go out and break a coffee cup and tell me how many fines you get
as opposed to larger fragments.
>
>:
>: Well, the real answer is that it depends, but in any case it is not
>: the most toxic substance known to man. It depends because plutonium
>: is a fairly mild alpha emitter.
>
>
>This is like saying something is a "fairly mild strain of Ebola."
Smoke and mirrors. Alpha particles do vary in energy but not generally
by enough to matter that much. The activity of the isotope in question
is more important, along with the energy of the gamma ray given off.
Pu is a fairly soft gamma emitter, Am, as an example OTOH, is fairly
hard.
>
>: Alpha particles are easily stopped
>: by almost anything.
>
>
>Including body tissues, which is where the danger comes in.
>
>: The danger comes from getting it in contact
>: with one's body and keeping it in contact for a long time (i.e.
>: years). If that happens, some form of cancer is likely, even if
>: only a small amount of plutonium is involved. Getting it on your
>: skin isn't dangerous, since most people bathe more often than once
>: every few years. Plutonium dioxide (the chemical form used in RTGs)
>: is not soluble in water.
>
>
>What happens when plutonium oxide encounters HCl?
Not much. Otherwise we'd have a much easier time of performing
experiments in the lab with pieces that have had time to develop an
oxide layer. Nitric acid's more appropriate for that job.
>
>: Even in the form of inhaled, extremely small particles, plutonium
>: isn't the most deadly substance known to man. The CRC Handbook of
>: Physics and Chemistry lists acceptable exposure levels to various
>: radioactive substances. I happened to look up the level for inhaled
>: plutonium today. It's 0.022 micro Curies, if you care. Most of the
>: other entries on the page (also for inhaled particles) were much
>: lower. I.e. out of a page full of radioactives, most were more deadly
>: than plutonium 238.
>
>According to Merck, the maxiumum permissable level of Pu238 in air is 7 X
>10(-13) uCi/cc. The maximum lifetime inhalation level is 0.2 ug.
If you can get that much to stay in your lungs, then yes, you've got a
problem.
BTW, fix your software. It's placing large numbers of blank lines on
the end of your postings.
Jim Meritt
In article <341890...@stanford.edu>, bmo...@stanford.edu says...
>If Ken were to take a
>Per your H20 counter-example, it's rather hard to powderize water so
>that people inhale enough to fill their lungs, but a little powderized
>Pu would be easy and disastrous....
Oh rah. And if someone were to take a tiny fraction of a gram of iron shaped
like a needle and push it into your eye, it would blind you. That makes iron
a blinding agent?
As long as you have to come up with deliberate physical assaults, almost
ANYTHING can be lethal.
sheesh!
Lloyd R. Parker
me...@cars3.uchicago.edu wrote:
: The rest is history? In what sense? As a military weapon? Using a
: advantageous, from a military point of view. In fact it is about as
: stupid as it gets.
The purpose of terrorism is to cause panic. Dead people can't panic.
People who know they're likely to die from cancer can. Of course, you'd
also have quite a few deaths at first from radiation sickness.
Lloyd R. Parker
Patrick Reid (pjr...@nbnet.nb.ca) wrote:
:
: Mr. Parker, you have been provided with a reference to two articles in
: peer-reviewed journals regarding the exposure of A-bomb workers to Pu.
: Why haven't you checked out the reference?
Can you give it again?
:
: By the way, the site you are referring to:
: http://ans.neep.wisc.edu/~ans/point_source/AEI/may95/plutonium_eff.html
: Is the site for Atomic Energy Insights, which is run by Rod Adams, a
: former nuclear sub navy guy. Not a student.
The "site," "anu.neep.wisc.edu" IS run by a student nuclear science CLUB
at the University of Wisconsin. As it says. (Universities don't normally
grant web sites to people not affiliated with them.) The "articles" are
summaries and opinions, with no references and no reviewing cited. Seems
more like an "urban legends" site than a scientific one.
Greg Trayling
me...@cars3.uchicago.edu wrote:
>
> In article <5v9v2l$h...@flare.convex.com>, schu...@convex.com (Richard A. Schumacher) writes:
>
> >and yet worries about Cassini is either ignorant or an idiot.
> Mind you, these two options are not mutually exclusive :-)
>
prof who took abunch of us out to lunch in undergrad. The whole
time he was ordering he was saying things like "...and with the
coffee I would like cream or milk but not both." The poor
waitress was totally confused by the end of the ordeal. She
thought he was deliberatley being a prick, didn't realize
he talked that way all the time.
He also added up the bill in his head, for fun, and spotted
two errors when it was delivered.
http://www.cs.uwindsor.ca/meta-index/people/traylin
Junkencrapenmailgespammen ist verboten
Tim Gillespie
> : question) is 86 years. Assuming a generation is 20 years, then, ahh...
> : I can't say exactly how little will be left after 12,000 generations.
> : Xcalc gives me zero, which means it's less than 16 bit floating point
> : precision can calculate. Put another way, all but one part in a million
> : would be gone after 1188 years or 60 generations.
>
**SIGH** Ignorance seems to know no bounds. There really is nothing
wrong with ignorance, unless the ignorant try to pretend they know what
they do not.
OK, 12,000 generations ar 20 years per generation, that's 240,000 years.
Pu-238 has a half life of 87.7 years, so that would be 240,000/87.7 =
2736 half lives. Now, take your calculator, and raise 1/2 (0.5) to the
2736 power. That is the fraction of Pu-238 remaining after 12,000
generations. What's that you say? Your calculator gives zero as the
answer? Well, that is because (0.5)^2736 is an increadibly small number,
meaning that *all* of the Pu-238 would have long decayed away after
12,000 generation.
> Further, you
> need to consider its decay products, most of which are also radioactive.
Pu-238 decays directly to U-234, which is 2805 times *less* radioactive
than Pu-238, with a half life of 246,000 years.
--
___ _____
Tim .'/,-Y" "~-.
Gillespie l.Y ^.
/\ _\_
i ___/" "\
| /" "\ o !
l ] o !__./
\ _ _ \.___./ "~\
X \/ \ ___./
( \ ___. _..--~~" ~`-.
` Z,-- / \
\__. ( / ______)
\ l /-----~~" /
Y \ /
| "x______.^
| \
j Y
Jim Carr
doug...@navix.net writes:
>
>Challenger maintained enough structural integrity to preserve
>identifiable human bodies.
Challenger maintained enough structural integrity to carry
living humans to the ocean, where they were killed by the
200 mph impact, a detail NASA does not like to publicize.
Certainly an RTG would not be damaged by this based on the
Apollo 13 example (which was smaller but also never intended
to reenter the earth's atmosphere at high speed).
--
James A. Carr <j...@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.
Jim Carr
or Beryllium, which proved to be quite a hazardous material in
the nuclear weapons industry, or that Hg compound that killed
a chemist recently -- right through her latex gloves.
Jim Carr
Frank Crary (fcr...@rintintin.Colorado.EDU) wrote:
:
: This claim is absurd. The half life of plutonium 238 (the isotope in
: question) is 86 years. Assuming a generation is 20 years, then, ahh...
: I can't say exactly how little will be left after 12,000 generations.
: Xcalc gives me zero, which means it's less than 16 bit floating point
: precision can calculate. Put another way, all but one part in a million
: would be gone after 1188 years or 60 generations.
lpa...@larry.cc.emory.edu (Lloyd R. Parker) writes:
>
>Depends on how much you start with -- A(sub)0, remember?
You are a college professor, do the arithmetic. As a chemist,
you must be able to calculate the number of atoms of Pu-238
in that RTG under two assumptions (that they gave the mass of
Pu or they gave the mass of the oxide). I will help you out
by telling you that 12,000*20/87.74 = 2735.4 and that the fraction
surviving is (0.5)^{2735.4} = 3.77 x 10^{-824}, so you now only
need to multiply 10^{-824} times the number of atoms you get.
Hint: add exponents.
Advanced math hint: use logs like I did to get my answer.
>Further, you
>need to consider its decay products, most of which are also radioactive.
So do so, but their specific activity is much less.
: Well, the real answer is that it depends, but in any case it is not
: the most toxic substance known to man. It depends because plutonium
: is a fairly mild alpha emitter.
>This is like saying something is a "fairly mild strain of Ebola."
This suggests that you have a quantitative estimate of the
life expectancy of persons exposed to equal masses of the
Ebola virus and plutonium oxide dust.
Your answer?
Uncle Al
Tim Gillespie wrote:
>
Do NOT crosspost to sci.chem this mindless crap flame thread.
When you wrestle with a pig you both get covered with pigshit,
but the pig LIKES it.
--
Uncle Al Schwartz
Uncl...@ix.netcom.com ("zero" before @)
http://www.ultra.net.au/~wisby/uncleal.htm
(Toxic URL! Unsafe for children, Democrats, and most mammals)
"Quis custodiet ipsos custodes?" The Net!
Uncle Al
Jim Meritt wrote:
>
Do NOT crosspost to sci.chem this mindless crap flame thread.
When you wrestle with a pig you both get covered with pigshit,
but the pig LIKES it.
Uncle Al Schwartz
Jim Carr
me...@cars3.uchicago.edu wrote:
: The rest is history? In what sense? As a military weapon? Using a
: weapon which kills your opponents within 20-30 years is hardly
: advantageous, from a military point of view. In fact it is about as
: stupid as it gets.
lpa...@larry.cc.emory.edu (Lloyd R. Parker) writes:
>
>The purpose of terrorism is to cause panic.
I see. So you are saying that people spreading panic about
Cassini are terrorists?
>People who know they're likely to die from cancer can.
What this means, of course, is that people who are exposed enough
to have a significant cancer risk, along with people who are not
exposed at all but don't know any better, will have twenty years
to seek vengence on whoever they think is responsible. That
would probably include all chemists and physicists, given the
carefully reasoned approach they have used to form their opinion.
>Of course, you'd
>also have quite a few deaths at first from radiation sickness.
Lets see some numbers, Lloyd. How much Pu are you going to
pour down their throats?
Uncle Al
Lloyd R. Parker wrote:
>
Do NOT crosspost to sci.chem this mindless crap flame thread.
When you wrestle with a pig you both get covered with pigshit,
but the pig LIKES it.
--
Uncle Al
Lloyd R. Parker wrote:
>
Do NOT crosspost to sci.chem this mindless crap flame thread.
--
Jim Carr
Richard A. Schumacher (schu...@convex.com) wrote:
: Which is why no one should be concerned about Cassini crashing.
: All the plutonium is in oxide form, so it won't burn. As long
: as one does not (a) use an acetylene torch to vaporize the RTG
: and inhale the vapor, or (b) eat the RTG, there is no risk. There's
: no other way to get any of that moderately dangerous plutonium into
: one's body.
lpa...@larry.cc.emory.edu (Lloyd R. Parker) writes:
>
>Gee, you don't think there's a chance the spacecraft could blow up (e.g.,
>Challenger)?
There is a fair chance that the rocket will blow up. As with
Challenger, where the crew survived the explosion, there is
zero chance that the RTG will be destroyed by such an event.
>Or that an explosion and fire from a crash could vaporize
>the material?
That would be a much lower speed impact than the device is
designed for. The risk that knowledgable people are worried
about is the risk that it will not miss the earth during its
flyby as it gets a gravitational boost. That has a fair
likelihood of dispersing the Pu, depending on details.
I am amazed no one is worried that the flyby, combined with the
effect of Clementine, will alter our orbit and kill everyone,
given the high level of the usual Cassini discussions.
Uncle Al
Michael Richmann wrote:
>
Do NOT crosspost to sci.chem this mindless crap flame thread.
When you wrestle with a pig you both get covered with pigshit,
but the pig LIKES it.
--
Uncle Al
Rodger Coghlan
Ian Gay wrote:
>
> In article <EGCyq...@midway.uchicago.edu>, me...@cars3.uchicago.edu wrote:
> [snip]
> >accumulation in the bones (plutonium chemistry is pretty similar to
> >calcium,
>
> What is your reason for saying that? Aqueous chemistry of Ca is essentially
> that of Ca++, whereas I don't think Pu++ exists at all, and common species
> like PuO2+ don't seem to me very Ca - like.
>
> [snip]
>
> *** To reply by e-mail, remove _nospam from address ***
If I remember correctly, it was strontium 90 that replaced calcium in
bones and had a 40k year 1/2life. Plutonium is in the wrong column of
the periodic chart (I will get out my copy of the chart from home and
post the appropriate info tomorrow)
Rodger
--
All opinions expressed are Mine
(mea culpa, mea culpa, Mea maxima culpa)
Timothy Melton
In article <341940a0...@news.cso.uiuc.edu>,
Trish <p-cr...@uiuc.edu**> wrote:
>On 11 Sep 1997 18:32:37 -0500, schu...@convex.com (Richard A.
>Schumacher) wrote:
>>Anyone who smokes or drives a car or eats cooked meat or sunbathes
>>and yet worries about Cassini is either ignorant or an idiot.
>
>I admit to not reading all of the posts on this particular thread. I
>was under the assumption (yeah I know, I know) that it was a thread
>regarding what was presumed to be "the most hazardous" etc... I don't
>know anything about Cassini so I guess according to you that makes me
>ignorant. Gosh, am I supposed to curl up and quit posting now that
Err, Trish? Slow down and re-read the sentence above. Here, I'll bring it
down here for you:
"Anyone who smokes or drives a car or eats cooked meat or sunbathes
and yet worries about Cassini is either ignorant or an idiot."
You don't know anything about Cassini, right? I would therefore be forced
to conclude that you are not worried about it. Would that be a fair
conclusion? So, based on just a smidgen of logic, I'd have to conclude
that the original statement does not apply to you.
smoke || drive || eat cooked meat || sunbathe && Cassini -> ignorant or idiot
>you have made this declaration? Get over yourself
Good advice.
Tim
--
Tim Melton t...@questconsult.com
Quest Consultants Inc. http://www.questconsult.com/~tam
P.O. Box 721387 (405) 329-7475
Norman, Ok 73070-8069 Fax: (405) 329-7734
me...@cars3.uchicago.edu
In article <5vbkhr$o...@larry.cc.emory.edu>, lpa...@larry.cc.emory.edu (Lloyd R. Parker) writes:
>me...@cars3.uchicago.edu wrote:
>: With respect to both these risks plutonium is way less dangerous than,
>: say, radium, and way less than many other radioactive substances.
>>
>Totally, utterly false.
>
Really? Any substantiation for this, other then media statements. I
trust you're aware that Radium has a significantly shorter lifetime
(thus higher activity) than Pu239. If not, then perhaps (being a
chemist) you're aware that Ra chemistry is very close to this of Ca,
thus it tends to accumulate in bones and stay there.
Mati Meron | "When you argue with a fool,
me...@cars.uchicago.edu | chances are he is doing just the same"
Jim Meritt
In article <EGDMH...@midway.uchicago.edu>, me...@cars3.uchicago.edu says...
>The rest is history? In what sense? As a military weapon? Using a
>weapon which kills your opponents within 20-30 years is hardly
>advantageous, from a military point of view. In fact it is about as
>stupid as it gets.
Probably want to go the other way: kill the enemy NOW with something that is
harmless (for your own troops) next week...
John Savard
OldN...@mindspring.com (Grinch) wrote:
> Apparently Dr. Cohen has publicly offered to eat as much plutonium
>as Ralph Nader would eat pure caffeine, saying the health risk is
>comparable, but so far Mr. Nader has declined.
Although plutonium is not highly toxic when eaten, and, as an alpha
emitter, its radiations are easily blocked, it is very dangerous in
small quantities when _inhaled_.
John Savard
me...@cars3.uchicago.edu
In article <5vblee$r...@larry.cc.emory.edu>, lpa...@larry.cc.emory.edu (Lloyd R. Parker) writes:
>Richard A. Schumacher (schu...@convex.com) wrote:
>: Which is why no one should be concerned about Cassini crashing.
>: All the plutonium is in oxide form, so it won't burn. As long
>: as one does not (a) use an acetylene torch to vaporize the RTG
>: and inhale the vapor, or (b) eat the RTG, there is no risk. There's
>: no other way to get any of that moderately dangerous plutonium into
>: one's body.
>
>the material?
>
Vaporize plutonium oxide? You must be kidding. There is a reason why
Richard mentioned acetylene torch. Even at the torch temperatures
it'll take minutes or more to get the stuff to vaporize. The heat of
an explosion, for few miliseconds (or even seconds) just won't do it.
Jim Carr
OldN...@mindspring.com (Grinch) wrote:
}
} Apparently Dr. Cohen has publicly offered to eat as much plutonium
} as Ralph Nader would eat pure caffeine, saying the health risk is
} comparable, but so far Mr. Nader has declined.
sew...@butterflynetcom.ca (John Savard) writes:
>
>Although plutonium is not highly toxic when eaten, and, as an alpha
>emitter, its radiations are easily blocked, it is very dangerous in
>small quantities when _inhaled_.
A distinction apparently lost on Mr. Nader, and many others, which
was the point Cohen was making.
Another distinction that is not made is that the particle size must
be in a particular range to be inhaled, and that the healthy lungs
of non-smokers often clear out the dust they inhale.
Yet another distinction is the form the Plutonium is in and which
isotope(s) you are talking about.
me...@cars3.uchicago.edu
In article <5vbn2m$3...@larry.cc.emory.edu>, lpa...@larry.cc.emory.edu (Lloyd R. Parker) writes:
>me...@cars3.uchicago.edu wrote:
>: The rest is history? In what sense? As a military weapon? Using a
>: advantageous, from a military point of view. In fact it is about as
>: stupid as it gets.
>
>
Do you realize how many people there are around who are going to die
in 30 years?-)
>Of course, you'd also have quite a few deaths at first from radiation
>sickness.
Will take a hell of a lot of the stuff to cause death from prompt
radiation sickness. You can cause way more prompt death using a
pickup truck and stuff one can get in any hardware store, as has been
amply proven.
Jim Carr
: and yet worries about Cassini is either ignorant or an idiot.
ah...@holyrood.ed.ac.uk (Gavin Whittaker) writes:
>
> No. There are some risks which people are prepared to take, given
>the pleasure they get from the activity. There are some risks which are
>needlessly imposed on them that they don't like.
Your assumption that this risk is either significant or needless
has not been explained or defended. It should be.
For example, there are many risks imposed on people that they might
not like if they knew much about them; putting 80 foot long triple
trailer semis on 2-lane roads might be one, transporting explosives
and poison gases on city streets and public highways might be another.
I classify both of these as more significant that the risk from
Cassini; whether they are needless or not would be a matter for debate.
> Because *you* may be prepared to take the risk does not automatically
>give you the right to impose it on others. Objecting to the imposed risk
>does not automatically qualify a person as 'either ignorant or an idiot'.
Objections that do not state the objective basis for the objection
might, however, be deserving of such a classification. Or it could
be that they are neither ignorant nor an idiot, but just see this as
a way to get people to halt space exploration. There are many people
who find discoveries made out in our solar system inconvenient to
their beliefs, for example. I do not discount hidden motives.
Uncle Al
Drew Davis wrote:
>
Do NOT crosspost to sci.chem this mindless crap flame thread.
--
Jim Meritt
In article <3418C9...@deathtospam.aracnet.com>,
ghar...@deathtospam.aracnet.com says...
>Interesting that folks are panicking about Cassini when we';ve already
>launched at least one probe with nuclear material on it--Vaoyager, to be
>exact.
Um, doesn't the Galelio (sp) have a RTG in it? And the second pass
gravity-assist past earth it was going FAST.
Of course, there is all those RORSATS, stuff from APOLLO,...
me...@cars3.uchicago.edu
In article <5vbr6p$9...@elf.wang.com>, mer...@wangfed.com (Jim Meritt) writes:
>In article <EGDMH...@midway.uchicago.edu>, me...@cars3.uchicago.edu says...
>
>
>>weapon which kills your opponents within 20-30 years is hardly
>>advantageous, from a military point of view. In fact it is about as
>>stupid as it gets.
>
>
>harmless (for your own troops) next week...
>
for some folks here.
Bruce Hamilton
"Charles Wm. Dimmick" <dim...@ccsu.edu> wrote:
>Ken Tough wrote:
>> The problem comes when it is inhaled as dust and gets trapped
>> inside your lungs. (As is the problem with asbestos).
>You need to define your terms. A search of dejanews will show my
>extensive previous postings on the non-hazard of chrysotile
>asbestos. Chrysotile comprises about 95% of the asbestos used in
>the United States, and is essentially harmless. It got a bad
>reputation because Crocidolite and Amosite asbestos will kill you.
A search of Dejanews will also detect several of my
postings on Asbestos. They note that it is the dimensions of
asbestiform fibres that is the critical parameter, not the
mineralogical definition. Fibres with widths greater
than 1um have not been implicated in the occurance of
lung cancer or mesothelioma, and significant numbers of
fibres with widths <0.3um usually have to be present [1].
Contrary to your claim, chrysotile fibres have been seen to
fall within the hazard region [2]. Both the width and the
aspect ratio of asbestiform fibres are considered to be
necessary to define hazardous asbestos fibres. A lot of
people have died from asbestosis and some of those solely
because various myths like " blue asbestos = hazard, white
asbestos = safe " were allowed to linger for far too long.
>There is absolutely NO relationship between Chrysotile and
>Crocidolite. They are not found together in nature and they are
>not used together in industry.
All of which is irrelevant, because mineralogical definitions
are no longer considered appropriate for defining hazardous
asbestiform species. My earlier postings have much more
detail.
Followups set to sci.chem.
[1] The Importance of Width in Asbestos Fiber Carcinogenicity
and its Implications for Public Policy
A.G.Wylie, K.F.Bailey, J.W.Kelse, R.J.Lee
Am.Ind.Hyg.Assoc.J. v.54 p.239-252 (1993)
[2] The Regulatory and Minerological Definitions of Asbestos
and Their Impact on Amphibole Dust Analysis.
Am.Ind.Hyg.Assoc.J. v.50 p.613-622 (1989)
Bruce Hamilton
Edward Rice
In article <3418C9...@deathtospam.aracnet.com>,
Greg Hartman <ghar...@deathtospam.aracnet.com> wrote:
>Interesting that folks are panicking about Cassini when we';ve already
>launched at least one probe with nuclear material on it--Vaoyager, to be
>exact.
We've been shooting up small nuclear payloads for decades. The "SNAP"
program, which stood for Satellite Nuclear Auxiliary Power, has been around
for more than thirty years. It's the scale of the new shots that are
upsetting people, I think, plus the fact that we're sending up plutonium
rather than shorter-lived isotopes that would become harmless fairly
quickly even if they were distributed on a population center.
I wonder what's behind the push to use plutonium. Surely nobody thinks
that those probes need to be sending messages back in 120,000 years. Why
aren't we using radioisotopes with far shorter half-lives?
Uncle Al
Jim Carr wrote:
>
Do NOT crosspost to sci.chem this mindless crap flame thread.
When you wrestle with a pig you both get covered with pigshit,
but the pig LIKES it.
--
me...@cars3.uchicago.edu
In article <5vburj$ipr$1...@news.fsu.edu>, j...@ibms48.scri.fsu.edu (Jim Carr) writes:
>Frank Crary (fcr...@rintintin.Colorado.EDU) wrote:
>:
>: This claim is absurd. The half life of plutonium 238 (the isotope in
>: question) is 86 years. Assuming a generation is 20 years, then, ahh...
>: I can't say exactly how little will be left after 12,000 generations.
>: Xcalc gives me zero, which means it's less than 16 bit floating point
>: precision can calculate. Put another way, all but one part in a million
>: would be gone after 1188 years or 60 generations.
>
>
> You are a college professor, do the arithmetic. As a chemist,
> you must be able to calculate the number of atoms of Pu-238
> in that RTG under two assumptions (that they gave the mass of
> Pu or they gave the mass of the oxide). I will help you out
> by telling you that 12,000*20/87.74 = 2735.4 and that the fraction
> surviving is (0.5)^{2735.4} = 3.77 x 10^{-824}, so you now only
> need to multiply 10^{-824} times the number of atoms you get.
>
> Hint: add exponents.
>
> Advanced math hint: use logs like I did to get my answer.
>
an Earth mass worth of Pu. Heck, make it a Universe mass (some 10^80
atoms).
Uncle Al
Uncle Al
Charles Wm. Dimmick wrote:
>
> Ken Tough wrote:
>
> > The problem comes when it is inhaled as dust and gets trapped
> > inside your lungs. (As is the problem with asbestos).
>
> You need to define your terms. A search of dejanews will show my
> extensive previous postings on the non-hazard of chrysotile
> asbestos. Chrysotile comprises about 95% of the asbestos used in
> the United States, and is essentially harmless. It got a bad
> reputation because Crocidolite and Amosite asbestos will kill you.
> Crocidolite. They are not found together in nature and they are
> not used together in industry.
>
It gets much better than that. People who smoke filter cigarettes have
lungs filled with cellulose triacetate microfibrils shed from the
filters. They are an excellent modality to transport and trap cigarette
tar deep within the lungs. Uncle Al calls it "protected to death."
Scandal, anyone?
Was it the Kent "Micronite" filter that was originally fabricated with
asbestos?
Uncle Al
Jim Carr wrote:
>
Do NOT crosspost to sci.chem this mindless crap flame thread.
When you wrestle with a pig you both get covered with pigshit,
but the pig LIKES it.
--
George Herbert
Note followups.
Lloyd R. Parker <lpa...@larry.cc.emory.edu> wrote:
>Gee, you don't think there's a chance the spacecraft could blow up (e.g.,
>Challenger)? Or that an explosion and fire from a crash could vaporize
>the material?
Yes, about 1 in 20 based on prior history of the Titan launcher.
No, there is no launch accident scenario which can generate the
magnitude of localized pressures and temperatures needed to breach
the RTG fuel pellet containment. The only credible release scenario
is absolute worst case accident during flyby. Even most flyby accidents
that lead to atmospheric entry won't release anything, though.
-george william herbert
Retro Aerospace
gher...@crl.com
Jim Carr
eb...@gate.nospam.net writes:
>
>>Post a cite Lloyd. Saying something's so doesn't make it so.
>
> How about the CRC Handbook of Chemistry and Physics, 70th Ed.
>(1989-1990), ISBN 0-8493-0470-9 (?), p. B-29:
If Lloyd sees this, that is not my idea of a good reference for
the chemical toxicity since it does not give an LD50 rate and,
more importantly, it does not mention *chemical* toxicity at all.
><begin quote>
> Because of the high rate of emission of alpha particles and the
> element being specifically absorbed by bone marrow, plutonium, as well
> as all of the other transuranium elements except neptunium, are
> radiological poisons and must be handled with very special equipment
^^^^^^^^^^^^^^^^^^^^
> and precautions. Plutonium is a very dangerous radiological hazard.
><end quote> ^^^^^^^^^^^^^^^^^^^
That danger being manifest on a time scale of decades.
> Doesn't give any hard data regarding toxicity.
Precisely.
Followups to sci.groups only.
Jim Carr
lpa...@curly.cc.emory.edu (Lloyd R. Parker) writes:
>
>The chemical toxicity of plutonium alone is enough to label anybody who
>says he would ingest it as a bona fide nut case.
The exposure limits on Plutonium are set entirely on its
radiological properties and uptake mechanisms, so perhaps
you (as a chemist) will enlighten us by providing the mass
of Pu in its different forms (metal, oxides) that constitutes
an LD50 (death in, say, a year as was the case with the
unfortunate chemist who got a drop of an Hg compound on her
latex gloves) exposure.
Please cite your source.
James Nicoll
In article <341890...@stanford.edu>,
Brooks Moses <bmo...@stanford.edu> wrote:
>Timothy P. Corbett wrote:
>>
>> In article <T80j0GAv...@dial.pipex.com>,
>> Ken Tough <k...@objectech.co.uk> wrote:
>>
>> >Its hazard depends on how it gets into you, though. If ingested,
>> >as you say, it will likely pass through without too much harm.
>> >The problem comes when it is inhaled as dust and gets trapped
>> >inside your lungs.
>>
>> heavy metal. And if it were dust, what manner of conveyence
>> would transport it into the lungs of large numbers of people?
>
>If Ken were to take a small quantity of plutonium, and make it into
>powder by some excessively easy way, and then sprinkle it over your
>house, it _would_ be dust and you would probably inhale some of it.
>Admittedly it would take a good bit of plutonium to sprinkle a large
>city, but it could be done fairly easily in a crowded market area --
>fill a nuke-capable bomber with a few just sub-critical piles of
>powderized plutonium, fly in low over downtown X-ville's city market,
>and let loose. The piles of powder descend as dust into the crowds, and
>the rest is history.
>
Wouldn't it be both cheaper and faster to use nerve gas or
some other chemical weapon? Pu is expensive whereas Raid(TM) is not.
ObUL: A UWaterloo bio prof was once poisoned by a grad student who
would empty a can of raid per day into the trailer they were
living in while studying blackflies in Northern Ontario.
--
About this time, I started getting depressed. Probably the late hour and
the silence. I decided some music would cheer me up.
Boy, that Billie Holliday can sing.
_Why I Hate Saturn_, Kyle Baker
me...@cars3.uchicago.edu
me...@cars3.uchicago.edu
In article <3419A8...@no.spam.com>, DW <M...@no.spam.com> writes:
>me...@cars3.uchicago.edu wrote:
>>
>>
>> Vaporize plutonium oxide? You must be kidding. There is a reason why
>> Richard mentioned acetylene torch. Even at the torch temperatures
>> it'll take minutes or more to get the stuff to vaporize. The heat of
>> an explosion, for few miliseconds (or even seconds) just won't do it.
>>
>> me...@cars.uchicago.edu | chances are he is doing just the same"
>
>
>without actually melting the material. This is a big problem in the
>production of nuclear devices.
>
It is not easy, at all, to create an aerosol of something using an
explosion. You've to optimize for this. Specifically you need an
explosive with denotation speed exceeding the speed of sound in the
material (TNT will do, RDX will be better) and place the explosive in
direct contact with the meterial you want to pulverize, without
intervening gaps which slow down the detonation wave. In short, you
would need to pack lots of high speed explosive in the container the
Pu is in. That's not the situation here.
Charles Wm. Dimmick
Ken Tough wrote:
> The problem comes when it is inhaled as dust and gets trapped
Larks
Lloyd R. Parker wrote:
>
> Larks ("La...@worldnet.att.net"@worldnet.att.net) wrote:
> : Again, a first estimate only, but a far cry from the
> : permissible body burden of Po. I cannot find the
> : permissible body burden of Pu-238 in literature
> : anywhere.
> :
> : It's interesting that The Gunniess Book of World
> : Records for many years listed (and perhaps still lists)
> : Pu as the "most poisonous element".
>
> Merck says, max. permissable level of Pu239 in air, 6 X 10(-13) uCi/cc.
> For Po210, 7 X 10(-11) uCi/cc. This would say Pu239 is 100 times more
> toxic when in air.
I disagree.
You are looking at the activities, not the quantity of material.
Activity of Pu-239 = 0.067 uCi/mg
Activity of Po-210 = 4,400,000 uCi/mg
So,
6E-13 uCi of Pu-239 is a particle weighing 9E-12 mg
7E-11 uCi of Po-210 is a particle weighing 1.6E-17 mg
Thus, by the numbers you've provided, the maximum amount
of Pu-239 permissible in air is about 567,000 times the
amount of Po-210.
Mountain Man
Uncle Al wrote:
>
> Jim Carr wrote:
> >
>
> Do NOT crosspost to sci.chem this mindless crap flame thread.
>
> When you wrestle with a pig you both get covered with pigshit,
Nonsense ... you shoot it first, then drag it out with rope.
Al - your trying to monopolise toxicity threads ...
When is the Uncle going to become diluted with fatherhood?
Pete Brown
--------------------------------------------------------------------
BoomerangOutPost: Mountain Man Graphics, Newport Beach, {OZ}
Thematic Threading: Publications of Peace and Of Great Souls
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QuoteForTheDay:
"I dont know half of you half as well as I should like;
and I like less that half of you half as well as you deserve."
This was unexpected and rather difficult.
There was some scattered clapping, but most of them were
trying to work it out and see if it came to a compliment.'
- JRR Tolkien (from 'The Fellowship of the Ring')
--------------------------------------------------------------------
DW
me...@cars3.uchicago.edu wrote:
>
>
> Vaporize plutonium oxide? You must be kidding. There is a reason why
> Richard mentioned acetylene torch. Even at the torch temperatures
> it'll take minutes or more to get the stuff to vaporize. The heat of
> an explosion, for few miliseconds (or even seconds) just won't do it.
>
> Mati Meron | "When you argue with a fool,
> me...@cars.uchicago.edu | chances are he is doing just the same"
Careful here. An explosion could, in theory, create an aerosol of PuO2
without actually melting the material. This is a big problem in the
production of nuclear devices.
Donald
.
Jim Carr
me...@cars3.uchicago.edu wrote:
: With respect to both these risks plutonium is way less dangerous than,
: say, radium, and way less than many other radioactive substances.
lpa...@larry.cc.emory.edu (Lloyd R. Parker) writes:
>
>Totally, utterly false.
There are two ways to classify the risk. One is by body burden.
There it is the specific activity that matters, and since that
is higher for Ra226, the allowed burdern for Ra226 is lower than
for Pu239. The excellent data on the effects of Ra exposure in
watch-dial painters was the basis for the epidemiology that set
this standard for many isotopes that end up in the bones.
The other way is by the different means the material can enter
the body. It is in the latter case, concerning the concentration
of Pu in the air _that_is_allowed_under_present_regulations_, that
plutonium is classified as exceptionally dangerous.
If the criteria were the risk if you accidentally had a drop
of it hit a latex-gloved hand while doing some wet chemistry,
it would not be classified as exceptionally dangerous.
: The
: claims of "most toxic substance known to mankind" are, to put it
: mildly, plain bulshit (I can't prove it ...
>So it's just your opinion.
You might find the article published as UCRL-JC-118825 and available
at
http://www.llnl.gov/csts/publications/sutcliffe/118825.html
as well as the citations therein interesting, since it presents
what scientists call a quantitative analysis of risk.
Note followups are to sci.groups only.
Michael Pelletier
In article <B03F27899...@ehrice.his.com>,
Edward Rice <ehr...@his.com> wrote:
>We've been shooting up small nuclear payloads for decades. The "SNAP"
>program, which stood for Satellite Nuclear Auxiliary Power, has been around
>for more than thirty years. It's the scale of the new shots that are
>upsetting people, I think, plus the fact that we're sending up plutonium
>rather than shorter-lived isotopes that would become harmless fairly
>quickly even if they were distributed on a population center.
I don't think it's the scale that's upsetting people, it's Caldicott,
Sternglass, and Gould's blatent misrepresentations and outright lies
(made in an effort to promote their respective books I suspect) being
swallowed whole by a scientifically illterate general public, which
is upsetting people.
The type of plutonium used in the RTG is Pu-238, which has a half-life
of 88 years, and emits only alpha radiation which can be stopped by a
sheet of paper. The shorter the half-life, the more radioactive
something is.
>I wonder what's behind the push to use plutonium. Surely nobody thinks
>that those probes need to be sending messages back in 120,000 years. Why
>aren't we using radioisotopes with far shorter half-lives?
The Voyager probes have ceased transmitting due to a combination of
low power and distance 20 years after their launch. The lifetime of
a plutonium battery is most certainly not as long as you say here,
though certainly far longer than the lifetime of a chemical battery
(which is the point after all).
I'd strongly suggest that you check out the following web page:
<http://ans.neep.wisc.edu/~ans/point_source/AEI/AEI_index.html#Batteries>
The articles listed there will give you a better understanding of how
RTGs work and what is involved in their operation. The key factor is
that Pu-238 is self-heating -- a lump of it can reach 500 C, while
emitting easily-shielded alpha radiation. This heat is then used with
a series of thermocouples to create electric current. Plutonium-238 is
unique in its combination of self-heating to high-enough temperature
to provide a significant temperature gradiant for thermocouples, its
easily-shielded alpha emissions, its high (4300F) melting-point and
insoluability in its ceramic form, and adequately long half-life to
provide a long battery lifetime.
-Mike Pelletier.
Joseph D. Warner
Grinch wrote:
> I've heard the line about "the most toxic substance known to man"
> countless times, but when I tried to look into it on the Web I found
> the research of Dr. Bernard Cohen, a physics professor at the
> University of Pittsburgh and former president of the Health Physics
> Society, who has calculated that ingesting a gram of plutonium
> increases radiation-related health risks only about as much as
> spending six months at 5,000 feet instead of sea level; say, in Denver
> instead of New York.
> Apparently Dr. Cohen has publicly offered to eat as much plutonium
> as Ralph Nader would eat pure caffeine, saying the health risk is
> comparable, but so far Mr. Nader has declined.
> I'm no expert in this field but Dr. Cohen's work seems to be peer
> reviewed. A sample is at http://www.syd.suburbia.net/~rlong/ff/p22.htm
>
I have heard Dr. Cohen lecture in the past on nuclear hazards. If you
ever have a chance to listen to him, please take the opportunity, even
if you disagree with his position. His analysis of the risks and the
risk mechanisms are thoughtful. He does not try to be overly
flambouyant but does a nice effort in comparing risks between nuclear
effects and other events that we are exposed too. He is open on the
assumations he is making and usually is very willing to discuss those. I
belief he is more aware of the underlying assumptions in his reasoning
than most people are; and he has analyzed most of them in respect to his
conclusions.
Richard A. Schumacher
>> >Its hazard depends on how it gets into you, though. If ingested,
>> >as you say, it will likely pass through without too much harm.
>> >The problem comes when it is inhaled as dust and gets trapped
>> >inside your lungs.
>>
>> But that's precisely the point. Pu is *not* dust, it's a
>> heavy metal. And if it were dust, what manner of conveyence
>> would transport it into the lungs of large numbers of people?
>If Ken were to take a small quantity of plutonium, and make it into
>powder by some excessively easy way, and then sprinkle it over your
>house, it _would_ be dust and you would probably inhale some of it.
>Admittedly it would take a good bit of plutonium to sprinkle a large
>city, but it could be done fairly easily in a crowded market area --
>fill a nuke-capable bomber with a few just sub-critical piles of
>powderized plutonium, fly in low over downtown X-ville's city market,
>and let loose. The piles of powder descend as dust into the crowds, and
>the rest is history.
If you want paranoid fantasies, worry about botulism toxin instead.
It's much easier to get and distribute than plutonium metal or oxide.
The only way that any quantity of finely divided plutonium has ever
been dispersed is through fission and fusion bomb tests, which together
have dispersed at least 10 tons of plutonium.
RTG safety has been demonstrated by previous accidents (one of them
the re-entry of Apollo 13).
--
FCC: Chairman Reed Hundt: rhu...@fcc.gov Commissioner James Quello:
jqu...@fcc.gov Commissioner Susan Ness: sn...@fcc.gov Commissioner
Rachelle Chong: rch...@fcc.gov
Richard A. Schumacher
>: Which is why no one should be concerned about Cassini crashing.
>: All the plutonium is in oxide form, so it won't burn. As long
>: as one does not (a) use an acetylene torch to vaporize the RTG
>: and inhale the vapor, or (b) eat the RTG, there is no risk. There's
>: no other way to get any of that moderately dangerous plutonium into
>: one's body.
>Gee, you don't think there's a chance the spacecraft could blow up (e.g.,
>Challenger)? Or that an explosion and fire from a crash could vaporize
>the material?
The point of the acetylene torch remark is that you have to hold the
fuel pellets at a high temperature for a while to get any fraction of
the plutonium oxide to vaporize. The rapid fire and flames of a
launcher accident looks impressive but they don't last long enough
to vaporize an RTG. Re-entry is worse but the heat would be absorbed
by burning up part of the RTG outer packaging.
There have been at least two accidents involving RTGs, one the explosion
of a Titan after launch, the other the re-entry of the Moon lander of
Apollo 13. Neither one caused the release of any plutonium into the
air. (If I recall correctly the Titan launch RTG was recovered and
re-used!)
Worry about something more probable, like getting shot in a minimart
holdup.
John Schilling
lpa...@larry.cc.emory.edu (Lloyd R. Parker) writes:
>Richard A. Schumacher (schu...@convex.com) wrote:
>: Which is why no one should be concerned about Cassini crashing.
>: All the plutonium is in oxide form, so it won't burn. As long
>: as one does not (a) use an acetylene torch to vaporize the RTG
>: and inhale the vapor, or (b) eat the RTG, there is no risk. There's
>: no other way to get any of that moderately dangerous plutonium into
>: one's body.
>Gee, you don't think there's a chance the spacecraft could blow up (e.g.,
>Challenger)? Or that an explosion and fire from a crash could vaporize
>the material?
Given that the boiling point of plutonium oxide is higher than the
flame temperature of the rocket fuel used by the Titan IV, no, there
is no chance that the explosion and fire from a crash would vaporize
the material. It would simply produce some very hot chunks of PuO2
wrapped in iridum, to be picked up by a hazmat team once they cooled
down. Actually, your local garbage collector could handle the job,
but in the interest of public relations a hazmat team would be used.
You might as well ask if turning a gas stove up to "high" will vaporize
your cooking untensils. There are things that can vaporize plutonium
oxide and/or iridium, but rocket explosions aren't on the list.
--
*John Schilling * "You can have Peace, *
*Member:AIAA,NRA,ACLU,SAS,LP * or you can have Freedom. *
*University of Southern California * Don't ever count on having both *
*Aerospace Engineering Department * at the same time." *
*schi...@spock.usc.edu * - Robert A. Heinlein *
*(213)-740-5311 or 747-2527 * Finger for PGP public key *
Ed Kaulakis
Steinn Sigurdsson wrote:
> Question is why they think the risk of Cassini to them
> (which is negligibly small IMAO) should be objected to
IMAO, a great deal of current Americana traces back to the grade-school
duck-and-cover drills of the late 50's and 60's, when the Rooskies were
gonna nuke our collective ass for sure any day now, yeah!
Considered purely as statecraft, this backfired big-time. It turns out
that scaring the crap out of generations of children does _not_ produce
docile and biddable perfect citizens of the National Security State. To
say the least. The wildly disproportionate[1] fear of, anger at, and
political intolerance of "radiation", particularly in the context of
"risk imposed willy-nilly by Them" is its lasting legacy.
Ed "My kids say they _like_ giant fireworks. We should all be very
proud and very very thankful. And careful with politicians." Kaulakis
[1] As compared for example to a ski vacation in Colorado.