Talk:Plutonium
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Information Sources
Some of the text in this entry was rewritten from Los Alamos National Laboratory - Plutonium (http://periodic.lanl.gov/elements/94.html). Additional text was taken from the Elements database 20001107 (via dict.org (http://www.dict.org)). Data for the table was obtained from the sources listed on the subject page and WikiProject Elements but was reformatted and converted into SI units.
Most dangerous substance known to man
Plutonium is by no stretch of the imagination the most dangerous substance known to man. It will give you cancer if you inhale plutonium dust but that's true for all alpha emiters, and in any event that won't kill you for a few decades.
Also removed the stuff about radiological bombs, because plutonium isn't very radioactive (and because it is hard to get), it's not a particularly good material for a dirty bomb especially in comparison with radioactive iodine or cesium.
- Well, what IS the most dangerous substance known to man, then, if it's not plutonium? Graft
- Off hand, it's guess that maybe a nerve agent like sarin. Also, one could argue that refined plutonium *is* one of the most dangerous substances known to man, not because of its inherent lethality, but because you can build bombs with it and you don't want the stuff lying around where bad people can get it.
- But by that logic so is hydrogen. - Omegatron 23:39, Mar 7, 2005 (UTC)
- Just on the logic above, about plutonium being the most dangerous substance because you can build bombs with it, that would probably make steel the most "dangerous" substance of all. You can build an a-bomb without plute, but you can't build one without steel. Nor can you build rifles, tanks or warships. Let's remember we're writing an encyclopedia article here. This sort of thing does not belong. Andrewa 11:46 Mar 8, 2003 (UTC)
- Tetanus toxin is in the few tens of ng/kg, some nerve agents are IIRC in the hundreds of ug/kg, and ricin has an average lethal dose of 100 ug (so actually a tad over a/kg). One molecule of ricin can kill a cell, but it has trouble entering, and can meet the wrong structure (eg the lysosome). I don't know about botulinum toxin, but it's under an ng/kg, and lethal doses have been in the several ng. As such, Pu doesn't even come close.
Regardless of what the most dangerous substance is, it's certainly not Plutonium. Naturally-occuring Radium is about 200 times more radiotoxic. Andrewa 23:31 Mar 7, 2003 (UTC)
- I don't remember specific LD-50 data, but plutonium salts are among the most toxic of all inorganic substances. N.B. that's chemical toxicity, not radiotoxicity. Mkweise 00:01 Mar 8, 2003 (UTC)
- LD50 (http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/L/LD50.html) data can't by definition be used to separate chemical and radiological toxicity, it is a measure of the overall effect of the substance. So whatever the source of this information, I'd double-check that you understood them. The other strange thing about this claim is, why focus on inorganics? The organic compounds (which include of course organic salts) of heavy metals (eg lead) are normally the most deadly. Is there any reason for thinking plutonium won't be the same? It will be difficult to find out, as the radiotoxicity is high enough to mask these effects anyway. Plutonium is very nasty stuff. But not as nasty as some people want to make you think. Andrewa 11:46 Mar 8, 2003 (UTC)
- My source on that is a nuclear war preparedness manual, ca. 1979, which was handed out to my class back in high school - so it is possible that it's exaggerated. It clearly states that unlike uranium, plutonium kills by (chemical) poisoning long before its radioactivity gets anywhere near dangerous levels.
- Not wanting to be unkind, but this sounds like a political document. Do you remember who wrote and printed it?
- As a further health warning on the above - one of the salient facts about uranium is that it kills by chemical poisoning long before its radioactivity gets anywhere near dangerous levels
- The nasty thing about inorganic toxins is that they accumulate over a lifetime as well as up the food chain. (N.B. organic acid salts of heavy metals are considered inorganic toxins, since the toxic ions are inorganic.) Organic toxins, while dangerous in much lower doses, generally (with a few notable exceptions like dioxins) biodegrade very rapidly, often in a matter of days or even hours. Mkweise 03:08 Mar 11, 2003 (UTC)
- Four problems here. One, the claim was about "inorganic substances", and these don't include organic salts regardless of what "inorganic toxins" might mean. So can we lay that one to rest? Two, some organic salts aren't "organic acid salts", as many metals such as plutonium, uranium and aluminium are amphoteric. Three, some salts (not many but some, and it depends a bit on the definition of a salt which is a bit controversial on this exact issue) don't ionise in food or in the body since they are not soluble in water. Four, it's not obvious what all of this is supposed to prove.
- Obviously this is a complex and controversial subject, and there's a lot of misinformation and guesswork in existing literature. Beware! Andrewa 20:44 Mar 11, 2003 (UTC)
- As regards Pu being one of the worst inorganics, how does it compare to dimethylmercury (organic, granted) or HCN (not sure if it's organic). For that matter, how does it compare to Cd or Hg salts? Pakaran. 00:02, 10 Aug 2004 (UTC)
I see the bit about radiological bombs has been put back in. I'm not going to remove it, for the moment at least. I think it would be good if someone a bit closer to politically neutral on the issue had a look at it.
More serious I think is the claim about first aid on the Manhatten project. It sounds like an urban myth to me, and I think it's put there to scare people. But it may be true, funny and horrible things happen in wartime. I have no evidence either way, so again I have not touched it. But maybe someone should. Andrewa 23:51 Mar 7, 2003 (UTC)
- In the late 1940s a secret project was initiated to evaluate the toxicity of Plutonium and where it concentrated by injecting "Terminally Ill" patients with various amounts of Plutonium salts solutions. Usually the injected limb was amputated within a few weeks and analyzed for distribution of the Plutonium. As these were "Terminally Ill" patients, none were expected to survive more than a few years at most. However a small number of these patients did recover from their original illness, and with no significant obvious problems due to the Plutonium. At least one of these patients was still alive in the late 1980s!!! -- RTC 00:05 Mar 8, 2003 (UTC)
- That would give a possible source of this myth, if myth it be. But it doesn't answer the basic question of whether there is some truth in it. I doubt it belongs in the article, myself. Andrewa 11:46 Mar 8, 2003 (UTC)
- I know I'm replying to a comment made almost a year ago, but it is worth saying that the plutonium experiments undertaken by Stafford Warren were largely to assess the medical benefits of injecting plutonium (as a form of primative, direct chemotherapy), at least that was the gist of what I read about what was apparently titled Operation Sunshine (which was the not-fantastic "Plutonium Files" book which focused almost solely on the 'human story' -- important, sure, but not everything). Also, the closest thing to 'plutonium exposure' during the Manhattan Project that I've heard of is the death of a technician by radiation poisoning during experiments on the critical mass of a plutonium sphere (it was (poorly) dramatized by John Cusak in the movie Fat Man and Little Boy), after which said sad technician's body was of course put through extensive autopsy and his head, of all things, got shipped into storage or something along those lines. But I can't seem to remember offhand which book I saw that in... arggg. --Fastfission 05:48, 10 Feb 2004 (UTC)
- I agree, true or false, the part about "amputation" does not belong and the proper context of the toxicity data should be made. -- RTC 00:39 Mar 11, 2003 (UTC)
- Quoting from http://www.oism.org/cdp/V10_05.htm:
The most toxic substances known to man are made by bacteria. Contrary to allegations by PSR, et al., plutonium is ``not a world-class toxicant, writes T. Don Luckey in a June 20 letter to Chemical and Engineering News. When injected intraperitoneally into mice, the LD50 (the dose that causes 50% deaths in 30 days) is about the same as that of the vitamin pantothenic acid.
On a scale in which plutonium has a toxicity = 1, the toxicities of other materials are:
- mercury chloride 100
- strychnine 1,000
- actinomycin D 10,000
- tetrodotoxin 100,000
- perfringens A toxin 1,000,000
- pestis toxin 10,000,000
- shigella toxin 100,000,000
- botulinal E toxin 1,000,000,000
- tetanus toxin 100,000,000,000
- botulinal B toxin 1,000,000,000,000
- botulinal D toxin 10,000,000,000,000
The EPA is more concerned about carcinogens than toxins, but plutonium doesn't make the grade there either. Plutonium-contaminated workers have a lower total cancer mortality: 88% that of unexposed workers.
- End quotation -- RTC 00:40 Mar 8, 2003 (UTC)
- Is that right? That's surely the result of poor statistics... otherwise you're saying that working with plutonium can help -prevent- dying of cancer. Graft
- I suspect the reason for the reduction in mortality is that their employers monitor their health much more closely, so cancers in these workers are usually caught at much earlier and more treatable stages. However that is only a guess. -- RTC 22:32 Mar 11, 2003 (UTC)
- I read it, and it's bullshit. The argument against linear no-threshold dose-response completely misunderstands the two-hit model for cancer generation and doesn't even begin to challenge it. Graft
- Have you any reasons for thinking hormesis and the two-hit model (I assume you mean Knudson’s work here) aren't compatible? They answer quite different questions. Perhaps this discussion should go to Talk:Radiation. Andrewa 18:33 Mar 14, 2003 (UTC)
I think what is important is that we try to come to a consensus as to what the key facts are, and what they key opinions are, and try to describe all of these in a readable and approachable way that makes it clear which is which.
I've had go! I'm not completely happy with the results but I'm sure they won't last too long! And I think we are making real progress.
The key question I think is what is "danger" and what is "toxicity". "Toxicity" can be measured and is a matter of fact. "Danger" is felt and is a matter of opinion. Does this help? I have not been consistent in this usage myself I realise. Andrewa 00:24 Mar 12, 2003 (UTC)
This set off my BS meter. Moving to talk until/unless someone can list a citation for this.
- According to some accounts, the accepted first aid technique for tissue exposure to plutonium during the Manhattan Project was immediate high amputation of the exposed limb. This is unlikely, as the focus of the Manhatten Project was the wartime development of an important weapon and industrial safety was not a high priority. The dangers of other key materials, such as beryllium, were not researched and documented until many years afterwards.
- I guess "according to some accounts" sounds more reputable than "I read it in a science fiction story"...
- Plutonium taken into the body moves quickly to bone marrow. Nothing can be done; the victim is finished. Neutrons from it smash through the body, ionizing tissue, transmuting atoms into radioactive isotopes, destroying and killing. The fatal dose is unbelievably small; a mass a tenth the size of a grain of table salt is more than enough-a dose small enough to enter through the tiniest scratch. During the historic "Manhattan Project" immediate high amputation was considered the only possible first-aid measure.
- - Robert Heinlein's short (fiction) story The Long Watch (full text here (http://dragon.rulez.cz/e-buk/Robert%20A.%20Heinlein%20-%20Past%20through%20Tomorrow.pdf), this story begins around p. 163.) The same story also describes plutonium as the most poisonous, and most deadly metal in the known world. --Calair 23:25, 7 Mar 2005 (UTC)
---
Rewrote. The toxicity of plutonium really isn't a "controversial topic." I don't know of anyone knowledgeable either in the anti-nuclear movement or outside that will seriously defend a statement that plutonium is magically toxic.
- Good rewrite. I'm still concerned that we've gone back to saying the plutonium is a "particularly deadly poison" when the evidence is that nobody ever has or ever will suffer such a fate, and that we've gone back to calling plute weapons a "category" when in fact non-plute weapons have always been rare exceptions, and that we're back to suggesting that plute might be useful as a radiological weapon, when if you blew up some spent nuclear fuel for example the fission products would be a much bigger problem than the plute. But we've made great progress on what the article said just a little while ago. Andrewa 02:27 Mar 12, 2003 (UTC)
- However, you should search for HREX site:.gov on the web - there USED to be a website at Argonne/Brookhaven covering human injection experiments of Pu, and they were all primary sources. (I'm not arguing that it's magically dangerous.) Worth putting in the article? But they're gone now, you know, that whole security thing. Kind of a bummer, they were really interesting to read. Maybe someday we won't have an asshat as POTUS. Maybe someone has an archive of them. Sword 03:25, 8 Dec 2004 (UTC)
- Because of its low half-life, there are only extremely tiny trace amounts of plutonium naturally.
Someone more knowledgable than I - I've been given to understand that transuranium elements simply don't occur at all naturally. Is this just a convenient oversimplification for the layperson? Is the above statement accurate? Graft
- It does occur in uranium ores, due to occasional neutron capture by U-238 followed by decay to Np-239 and Pu-239. But as these events are VERY infrequent (they depend on spontanious fission rate of U-235 as well as neutron capture cross section of U-238) compared to the half-life of Pu-239, the levels can be practically ignored. I don't remember exact figures, but as I understand it the total amount of "naturally occuring" Plutonium in the entire earth is measureable in micro-gram quantities. The amount mankind has manufactured in reactors is many tons. -- RTC 02:30 Mar 14, 2003 (UTC)
- The explanation is that as analytical techniques improve, previously undetectable quantities become detectable. I don't think there's any proposal to change the status of plutonium to "natural" rather than "artificial", but that's only one of several reasons that this distinction has now blurred a little. Two others are the recognition that plutonium was once more common on earth than it is now, and the discovery of natural "fossil reactor (http://www.curtin.edu.au/curtin/centre/waisrc/OKLO/index.shtml)" sites in Gabon. Andrewa 17:20 Mar 14, 2003 (UTC)
- Actually, any plutonium detected by "analytical techniques" is almost certainly contamination from unfissioned plutonium in the fallout from the 1940s through 1960s bomb tests. Even in modern uranium ores (as far as I know) the "naturally occuring" levels are estimates based on spontanious fission rates, capture cross sections, and decay rates. -- RTC 19:09 Mar 17, 2003 (UTC)
- Webelements says "Plutonium is found in trace quantities in uranium ores but, in practice, normally it is synthesised by the transmutation of uranium. However, it is now found in very small quantities in some areas as a result of fallout from atomic bombs and from radiation leaks from nuclear facilities." I thought that mass spectrometers were now sensitive enough to detect the plutonium in uranium ores, but I could be wrong. This would not be contamination if so, as there hasn't yet been time for man-made plute to invade the geology to this extent. Andrewa 21:25 Mar 17, 2003 (UTC)
Uhm, where do we get botulin toxin (lethal dose in the ng/kg range) as being "billions of times more toxic than plutonium?" That would imply that one can survive several g/kg of plutonium, making it safer than caffeine? A gram of plutonium is probably a lethal dose I'd say, especially in soluble form. Pakaran. 04:29, 1 Mar 2004 (UTC)
- According to this page (http://russp.org/BLC-3.html), the author challenged Ralph Nader to consume as much caffeine as the author would plutonium. --NeuronExMachina 07:38, 6 Aug 2004 (UTC)
- I personally think it's a lot clearer now. It may need some slight NPOV tweaking, though. --NeuronExMachina 01:48, 10 Aug 2004 (UTC)
I've converted this over to the Elements WikiProject format. Unfortunately, I've been interrupted and will have to leave it for now having made the table and folded the old text into the standardised headings format (with a few minor modifications to alter the flow -- I hope they haven't upset anybody with a strong view on the toxicity issue, but you may want to check through). Still to do:
- Make the custom Plutonium image
- Expand the text with the various bits and bobs that are usually put into elements.
- Try and chase down alternate sources of data for some of the stuff that I couldn't find for the table.
Sources of data used in the table were webelements.com (http://www.webelements.com) and environmentalchemistry.com (http://www.environmentalchemistry.com). I will try and come back to this in the next few days if no one else sorts it out first. -- Bth 14:02, 6 Mar 2004 (UTC)
- OK, the image still needs doing, but it's not the only one of the elements to need that ... --Bth 16:10, 9 Mar 2004 (UTC)
Recent added paragraph: "Orally, plutonium is less toxic than several common substances, including caffeine, acetominopnen, some vitamins, (pseudo)ephedrine, all narcotic pain killers (including codeine) and any number of plants and fungi. It is perhaps somewhat more toxic than absolute alcohol, but less so than tobacco and most illegal drugs (some such as LSD and marijuana are not or barely toxic). As such, it is debatable whether plutonium should even be classified as a poison."
This seems almost ridiculously exaggerated. Supporting quantitative evidence should be provided or it should be deleted if none can be cited.
- I think the above statement is self-evident, especially with respect to aspirin, a dangerous substance that would be a precription drug if it were not grandfathered in. What is happening is that there is conflation with plutonium's use in bombs. Now radium, that is dangerous. Fred Bauder 11:59, Aug 10, 2004 (UTC)
It is great so much effort has gone into creating a fine treatment of plutonium toxicity, but does it belong on the plutonium page anymore? 5 paragraphs seems out of proportion to the rest of the article, which ought to be a mundane element page talking about melting points and isotopes.
Any reason I shouldn't say "plutonium is toxic, but no especially so." and cut and paste the rest into Plutonium Toxicity?
- I think that's an excellent idea. There's still a lot of weasel-talk in the current article. Basically, some people still don't want to admit that the plute toxicity myth was and is both deliberate propaganda and a whopping big lie. The problem here is, the facts make this painfully obvious, but some significant public figures have attached their names to the myth just the same.
- Criticality and proliferation issues aren't connected to toxicity except in a political sense. Ideally, we'd move all the politics into another article, perhaps Plutonium and politics, and battle out an NPOV presentation of these issues there. Andrewa 00:37, 5 Oct 2004 (UTC)
- I wonder if the name has any bearing on the image of Plutonium. It does sound vaguely similar to Pollution ( "Pollute-tonium"). Just a thought.
Vandalism - a suggestion
This talk page was vandalised by a couple of anons, who deleted sections out of some of my posts to render them nonsensical. I guess they didn't like what I said, and I think I can understand that. Telling lies about plutonium is something of an industry all of its own, and accurate Wikipedia articles threaten it.
Not that this article is perfect by any means! Lots of weasel-words in there still. That's why I think this talk page is important (and so do others, obviously).
I think I've got it back to rights. It wasn't a simple revert as there had been good-faith contributions in the meantime which I didn't want to lose, or even complicate their histories as at least one is unsigned. And I guess it will happen again, so I suggest anyone updating this page check for recent vandalism, and make your update to the last unvandalised version, which will painlessly revert the corruption. Andrewa 10:50, 18 Jan 2005 (UTC)
"complete"
What does "Complete" mean in the sentence: "Complete detonation of plutonium will produce an explosion of 20 kiloton per kilogram."?
It could be taken to mean total fission of the Pu into daugher nuclei. This would release a phenomenally huge amount of energy. Much more than 20kt/kg wouldn't it? I understand this is partially done with tritium boosting.--Deglr6328 00:46, 19 Jan 2005 (UTC)
- I took it to mean fissioning of all the Pu nuclei. To check its reasonableness empirically, we could try to find figures as to the efficiency, yield and pit mass of a pure plutonium detonation, such as little boy or the trinity test. Or theoretically, I guess the figure given is just the energy release per fission (there's about 220 mev of binding energy release, which doesn't count subsequent radioactive decay which is significant in a reactor but probably not here) multiplied by the number of atoms per kilogram, so we could reperform this calculation. Can you take it from there? What leads you to believe the figure given is not reasonable?
- Tritium is used for two purposes: It's a fuel for the easiest (lowest temperature and pressure) fusion reaction, and it's used as a neutron source to boost the efficiency of predominantly fission bombs. It's the second role you are describing here, and as you imply, it doesn't result in perfect efficiency by any means. Andrewa 19:56, 19 Jan 2005 (UTC)
- hm. one Kg Pu239 = 4.184 mol = 2,519,665,271,966,527,196,652,720 atoms * 220MeV= 5.543263598X10^32 eV= 88,812,864,488,134 J= 21.22 Kt TNT...........huh...whadda know...just seemed too low I guess.
- Anyway, the previous sentence "The critical mass for an unreflected sphere of plutonium is 16 kg, but through the use of a neutron reflecting tamper the pit of plutonium in a fission bomb is reduced to 10 kg, which is a sphere with a diameter of 10 cm." should specify the isotope that this is true for....I don't know it but prolly 239, yes?--Deglr6328 07:56, 20 Jan 2005 (UTC)
--- occurrence Dalrymble in book The Age of the Earth,1991, lists many isotopes as evidence of old earth. All isotopes t1/2>80 Myr are found in nature. Pu-244 is among them. Clearly originate from supernovae and stars just like other permanent elements (uranium, iron etc) on earth. Isotopes t1/2 <80 million yrs not found unless result of some continuing nuclear process (like short live Radon-222 from uranium etc). --MrKAT ,6 Feb 2005.
One of the problems faced by the Manhattan Project was constraining the fissile material for as long as possible before it blew itself apart. Unfortunately, that is still a constraint on obtaining anywhere near the theoritical maximum available energy.
And, in discussing critical mass, I've seen reports where the critical mass of Pu-239 was as low as 200 grams using an ideal Beryllium reflector. The Beryllium aids by adding large numbers of photo neutrons to the process.
Why reactor-grade plutonium is unsuitable for making a bomb
I thought appropriate to point out that small contents of 240Pu make the material proliferation-resistant, and why.
--Philipum 12:01, 24 May 2005 (UTC)