Talk:Polonium

Article changed over to new Wikipedia:WikiProject Elements format by maveric149. Elementbox converted 12:28, 10 July 2005 by Femto (previous revision was that of 06:33, 9 July 2005).

Information Sources

Some of the text in this entry was rewritten from Los Alamos National Laboratory - Polonium. Additional text was taken directly from the Elements database 20001107 (via dict.org), Webster's Revised Unabridged Dictionary (1913) (via dict.org) and WordNet (r) 1.7 (via dict.org). Data for the table was obtained from the sources listed on the main page and Wikipedia:WikiProject Elements but was reformatted and converted into SI units.

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Talk

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I added a bit about the naming of Polonium in the history section. Both her biography of Pierre and her dauther's biography of her specifically mention the naming of Polonium to cause attention to the plight of Poland, which was dominated by Russia and not recognized as a country. I bring it up because of some political controverys in the naming of new elements have come up, and I want to make it clear this is not new. It also links back to French attitudes towards her when a scandal broke out. [69.0.127.128]

I editied out erronius data that was entered stating that PO is not dangerous to humans. I assume this was vandalization after the news of the death of Alexander Litvinenko, who was found with PO 210 in his body. 00:12, 25 November 2006 (KST)

Citation from main page: Of the 18 passed on to the HPA, three will now be checked for contamination by Polonium 210, the highly radioactive element believed to have killed the former agent who died at University College Hospital last week. end cit. Will we have to edit that every week, from now? Install a week counter? w.

Current event?

I removed the current event tag once, and it got re-added, and I can't find who did it to ask the user why. I don't think it should be there, since Polonium is NOT a current event. The poisoning is the event. Information on Polonium isn't going to 'change rapidly'. Maybe if the year was in the late 1800s that would make sense. Dancraggs 01:19, 28 November 2006 (UTC)

Disputed

The article states, "The great radioactivity of polonium and its immediate neighbors to the right on the periodic table, and its stark contrast with lead and bismuth, is due to the great instability of nuclei containing 84 or more protons, especially when they also contain 128 neutrons, which causes them to be extremely unstable and rapidly emit alpha particles." However, lead 210 is an isotope with 128 neutrons, and it is primarily a beta emmiter (with some alpha emmition) with a half life of 22.3 years (source). This contradicts the statement that nuclei with a neutron number of 128 are all very unstable alpha emmiters. Polonium 12:26, 2 April 2006 (UTC)

-- below: perhaps "proton rich isotopes" should be "neutron rich isotopes" since isotopes differ by number of Neutrons not Protons. -eb.

Synthesis by (p,n) and (p,2n) reactions It has been found that by proton bombardment of bismuth using a cyclotron that the longer lived isotopes of polonium can be formed. Other more proton rich isotopes can be formed by the irradation of platinium with carbon nuclei.[8]

Irksome

Po is very nasty, it has an ability to go through glovebox gloves and get into the air. As I understand it, it is worse even than Pu-238. For those who do not know it, if you put a lump of Pu-239 as the sintered dioxide in a glove box or even on your desk (then leave it for a week) then the alpha contamination near will be next to nothing. Do the same thing with Pu-238 and the whole of the inside of the box will be all be active. Po can do the same thing, but it has an even worse reputation than Pu-238.Cadmium

• I was not disputing that it is nasty stuff, simply that 'irksome' is a subjective word, and as such should be replaced with something else in an encyclopedia article which should be objective. StealthFox 23:04, 14 May 2006 (UTC)

Contradiction

The fatuous comment is made that "what is remarkable is that it poses no risk whatsoever to anyone", whereas a bit later the statement is made that it is highly toxic. Would someone please correct these statements with a proper reference?

Alexander Litvinenko

It has been announced that Alexander Litvinenko was killed by a "major dose" of Polonium 210. [1] --jmb 15:40, 24 November 2006 (UTC)

The Metropolitan Police and Health Protection Agency appear to being careful not to say that he was poisoned, they say that they are looking for the source of the Polonium 210. [[2]] [[3]]--jmb 17:02, 24 November 2006 (UTC)

The article states the FSB poisoned Litvinenko. Either the author of that portion of the article broke a major conspiracy, forgot/failed to cite sources, or it does not belong in Wikipedia whatsoever. (Edit: now says Litvinenko blamed the FSB, which is proper, as a note dictated by Litvinenko directly implied that).

To even things out, shouldn't it be stated that both Putin and FSB had officially denied any involvement?

Why is it even necessary to mention in this article, "Traces of polonium were found in several locations he had visited shortly before becoming ill. [2] Litvinenko on his deathbed blamed his death on deliberate poisoning by the FSB (the successor organization of the KGB) and ultimately Russian President Vladimir Putin. [3]" This paragraph is not about Polonium, but about the who poisoned Alexander Litvinenko and should be moved.Bladeofgrass 11:23, 25 November 2006 (UTC)

The added comment "Putin loves it." Cute comment. Good to have a little humour now and then, even though the link is only suspected to my understanding. Given the purpose of Wikipedia, in time it should go. In the longer term, my thought is a link re a famous suspected or confirmed case of poisoning by Po of Alexander Litvinenkoto be added to this article. I mean this with no disrespect to Alexander's death. Historically significant speculations and established facts can be recorded there.

Returning to humour. There is a role for humour in any serious endeavour! The right dash in my view helps quality outcomes. CofE001 00:14, 26 November 2006 (UTC)

I am making the following change: The article says Litvinenko was "allegedly poisoned" by 210PO. This isn't factual. He was most certainly poisoned by 210PO, that is a fact. He was allegedly murdered by poisoning. 24.219.97.39 22:47, 27 November 2006 (UTC)

It was also found on more than one plane. Doubtful that more than one KBG guy was sent to nuke him. Likely a smuggling ring playing with some nasty stuff, anyone from Russia who met with Litvinenko is probably staring at some bright lights in a basement right now.

I really cant figure how traces of this substance might be left on a 'plane which has been used to carry it, unless the substance was in a very insecure comtainer, or someone was deliberately leaving traces. Laurel Bush 17:12, 30 November 2006 (UTC).

Polonium in Cigarettes

Polonium is studied in a few nuclear research laboratories where its high radioactivity as an alpha-emitter requires special handling techniques and precautions.

Polonium -210 is the only component of cigarette smoke that has produced cancers by itself in laboratory animals by inhalation - tumors appear at a level five times lower than the dose to a heavy smoker.

Lung cancer rates among men kept climbing from a rarity in 1930 (4/100,000 per year) to the No. 1 cancer killer in 1980 (72/100,000) in spite of an almost 20 percent reduction in smoking. But during the same period, the level of polonium -210 in American tobacco had tripled. This coincided with the increase in the use of phosphate fertilizers by tobacco growers - calcium phosphate ore accumulates uranium and slowly releases radon gas.

As radon decays, its electrically charged daughter products attach themselves to dust particles, which adhere to the sticky hairs on the underside of tobacco leaves. This leaves a deposit of radioactive polonium and lead on the leaves. Then, the intense localized heat in the burning tip of a cigarette volatilizes the radioactive metals. While cigarette filters can trap chemical carcinogens, they are ineffective against radioactive vapors.

The lungs of a chronic smoker end up with a radioactive lining in a concentration much higher than from residential radon. These particles emit radiation. Smoking two packs of cigarettes a day imparts a radiation dose by alpha particles of about 1,300 millirem per year. For comparison, the annual radiation dose to the average American from inhaled radon is 200 mrem. However, the radiation dose at the radon "action level" of 4 pCi/L is roughly equivalent to smoking 10 cigarettes a day.

In addition, polunium-210 is soluble and is circulated through the body to every tissue and cell in levels much higher than from residential radon. The proof is that it can be found in the blood and urine of smokers. The circulating polonium -210 causes genetic damage and early death from diseases reminiscent of early radiological pioneers: liver and bladder cancer, stomach ulcer, leukemia, cirrhosis of liver, and cardiovascular diseases.

The Surgeon General C. Everett Koop stated that radioactivity, rather than tar, accounts for at least 90% of all smoking-related lung cancers. The Center for Disease Control concluded "Americans are exposed to far more radiation from tobacco smoke than from any other source."

Cigarette smoking accounts for 30% of all cancer deaths. Only poor diet rivals tobacco smoke as a cause of cancer in the U.S., causing a comparable number of fatalities each year. However, the National Cancer Institute, with an annual budget of $500 million, has no active funding for research of radiation from smoking or residential radon as a cause of lung cancer, presumably, to protect the public from undue fears of radiation.

If the average American knew how many pCi's of polonium he/she/baby had in their system they would faint - nonsmokers have less but still a surprising amount. ( Carrots,etc are grown with the same fertilizer components as tobacco. ) Greatgranddady smoked and didn't get cancer, greatgrandma didn't smoke and didn't get cancer - now all bets are off ( only arguing whether you are less or more likely and which type would you rather get ). I hope someone is making good money off this - and I hope he smokes 4 packs a day.

Availability of Polonium

You can't just buy a milligram of Polonium on e-bay or repeat the Curies' experiment in your basement. Is Polonium availability restricted to governments, or is it also available in University research labs or hospitals? It seems like such a dangerous element should be strictly controlled. Also, is it possible to trace a particular sample of Polonium to its source based on trace amounts of contaminants?

You can buy it right here (if you are in the US). --startaq 23:33, 24 November 2006 (UTC)

That website seems a little questionable...so anyone can buy radioactive substances without any license? Jumping cheese ^Cont@ct 11:49, 26 November 2006 (UTC)

That outfit, United Nuclear Scientific Supplies, is a real reagent supplier for backyard experimenters. They are occasionally in a bit of hot water, but mainly about the pyrotechnics, not the radioactivity. Note that their polonium-210 product is 0.1 microcuries, less than 1/5000 of the 525 microcurie lethal dose discussed in the article. Even United Nuclear (or their "NRC licenced isotope manufacturer") would probably ask some questions if someone told them they'd like 10,000 of those, please... --mglg_(talk) 23:00, 26 November 2006 (UTC)

Staticmaster brushes have hundreds of microcuries of Po [4]. Thanks for the info re Po decay. 67.117.130.181 01:39, 27 November 2006 (UTC)

Looks like General Electric is the original source of the Po-210 "Static Eliminators". The picture shows it to be similar to the "Staticmaster" device. This part is available by mail order. See details below:

GE Static Eliminator for PCTE (99080)

• Polonium 210 encased in stainless steel housings
• 500 microcuries
• Part # 1215174
• Model # STATIC0001
• Price: US $71.00 [5]

Who ever got ahold of the isotope would probably get it from a nuclear reactor or a nuclear accelerator.

Forget about industrial use of Polonium in antistatic agents. Judging from my reading of some Internet open sources it looks like, that Polonium is particularly interesting for the military. http://en.wikipedia.org/wiki/Nuclear_waste mentions Po in connection of dismantling nuclear weapons - either as a trigger substance or as a source of energy for nuclear rockets (to generate heat and electricity - the same way as it was used by Russian Lunochod). I am not an expert chemist or nuclear chemist, but can anyone write more about it?

Plagiarism in section Precautions

The following two paragraphs under the section Polonium#Precautions are lifted from a listed external link almost word for word:

Polonium is a highly radioactive and toxic element and is dangerous to handle. Even in milligram or microgram amounts, handling polonium-210 is very dangerous and requires special equipment used with strict procedures. Direct damage occurs from energy absorption into tissues from alpha particles.

The maximum allowable body burden for ingested polonium is only 1100 becquerels (0.03 microcurie), which is equivalent to a particle weighing only 6.8 × 10-12 gram. Weight for weight polonium is approximately 2.5 × 1011 times as toxic as hydrogen cyanide. The maximum permissible concentration for airborne soluble polonium compounds is about 7,500 Bq/m3 (2 × 10-11 µCi/cm3).

• Los Alamos National Laboratory – Polonium

--Liulk 03:50, 25 November 2006 (UTC)

Might be a bit of a problem given that this doesn't appear to be in the public domain [6]. Nil Einne 16:31, 25 November 2006 (UTC)

BTW, today's NY Times article gives the figure for toxicity as 250 million times more toxic than cyanide. I assume the LANL figure is correct, and the NYT reporter just made a mistake in converting.--24.52.254.62 16:49, 25 November 2006 (UTC)

Dose due to internal Po

The commited dose due to intermal Po, is that a dose commitment over many years or over a shorter time. I think that the editor who made that addition should make it more clear.Cadmium

Typo

the successor oranization of the KGB -> organization

Solid State Form

The current page states:

The alpha form of the Po solid is cubic (Po-Po distance is 3.352 Å), it is a simple cubic solid which is not interpenetrated. A myth has grown up from a single sentence in one of the original papers on the crystal structure as determined by X-ray powder diffraction. Below is a diagram of a triple interpenetrated cubic solid, while for Po this is not the structure a reasonable number of real examples of such an interlocking network have been found.

This is very confusing. First, what is the myth? It sounds as if the myth were that Polonium's crystal structure is interpenetrated, but that's not at all clear. Second, the third sentence's structure is very convoluted.

Assuming I understand the myth, I'd suggest changing this to the following:

The alpha form of Po is a simple cubic solid (Po-Po distance is 3.352 Å). There is a myth that Polonium's crystal structure is interpenetrated, arising from a single sentence in one of the original papers on the crystal structure as determined by X-ray powder diffraction. Below is a diagram of a triple interpenetrated cubic solid; while this is not the crystal structure of Po, real examples of such an interlocking network have been found.

If I'm right, would someone who can confirm this make this change? Dtgriscom

Yes you have got it right.Cadmium

Power output of Polonium 210

Until a few days ago the article stated that the power output of 1g of Po 210 was 140W. This was changed to 150W by 84.190.155.226 with no explanation (AFAIK). Other references (excluding news sites which may well have taken their figure from wikipedia) state 140W nuenergy.org, jlab.org, while globalsecurity.org states that the power output is 120W/g.

My rough and ready calculation came to 138W, so I am wondering why it was changed and what data is being referenced to support this change? Gloop 15:12, 25 November 2006 (UTC)

Probably either a mistake or sneaky vandalism. I suggest you change it back given the evidence to the contrary Nil Einne 16:33, 25 November 2006 (UTC)

Done Gloop 18:25, 25 November 2006 (UTC)

I get 144 watts, so maybe there was just some rounding issue based on slightly different approximations. My calculation (please check it) went: the half-life H is 138.376 days or 138.376*86400 seconds. The amount remaining in a sample after T seconds is 2**-(T/H) so the amount that's decayed after 1 second is 1-2**(1/H) = 5.797e-8 of the starting sample. For 1 gram, since the atomic weight is 210, the number of atoms is 6.022e23/210 = 2.8676e21. So the number of decays per second is 5.797e-8*2.8676e21 = 1.6625e14. The energy per decay is 5.407 MeV or 8.663e-13 joules. Multiply by the number of decays per second and you get power in watts, 144.025 watts.

Wrong year of discovery

The article states that Polonium was discovered in 1897, while Encyclopædia Britannica and numerous other sources state it was discovered in 1898. Please fix this. 85.157.76.171 18:01, 25 November 2006 (UTC)

Is there a cite other than EB?

Pfützner M. (1999). "Borders of the Nuclear World --- 100 Years After Discovery of Polonium". Acta Physica Polonica B. 30: 1197. {{cite journal}}: Text "issue 5" ignored (help) schould state the date for the discovery --Stone 10:16, 28 November 2006 (UTC)

• Kabzinska K. (1998). "Chemical and Polish aspects of polonium and radium discovery". Przemysl Chemiczy. 77: 104–107. {{cite journal}}: Text "issue 3" ignored (help)

• Adloff J. P. (681–688). "The centennial of the 1903 Nobel Prize for physics". Radichimica Acta. 91: 2003. {{cite journal}}: Text "issue 12" ignored (help)CS1 maint: date format (link) or even better here.

--Stone 10:26, 28 November 2006 (UTC)

One of the articles above states: P. and M. Curie announced the discovery of polonium in July 1898. Curie P., Curie M. (1898). Comptes Rendus. 126: 1101. {{cite journal}}: Missing or empty |title= (help)

http://nobelprize.org/nobel_prizes/physics/articles/curie/ also states 1898.--Stone 10:36, 28 November 2006 (UTC)

Polonium in Fiction

Is this really wikipedia-worthy?

A precedence for such entries has been established under the wiki entry "Radiation Poisoning".

Then maybe it should be moved to that article. Bladeofgrass 19:07, 25 November 2006 (UTC)

Moved to fictional applications of real materials. Femto 19:16, 25 November 2006 (UTC)

As the originator of the "Polonium in Fiction" modification, I think the above change is an improvement. Thanks.

Why the protect?

Why has this article been semi-protected? It wouldn't seem like a high-risk article for vandalism. Alethiophile¹2₃ 23:16, 25 November 2006 (UTC)

Almost certainly because of the Litinvenko incident, which is current. Bryson430 19:16, 26 November 2006 (UTC)

lethal dose calculation

The lethal dose calculation has gotten messed up since last night. The errors in the current version should be pretty obvious to anyone up to the task of fixing them. 67.117.130.181 22:15, 26 November 2006 (UTC)

-- I've now attempted a fix, could someone please check it. 67.117.130.181 02:10, 27 November 2006 (UTC)

--Is it valid to use committed effective dose equivalent (CEDE) to calculate the dose required for death from acute radiation syndrome? I thought the CEDE was used to estimate long-term cancer risk with relatively low doses, not acute effects from high doses. Acute radiation syndrome typically requires a whole-body dose (or close to whole body). It is presumably harder to achieve a whole-body dose with an alpha emitter like polonium-210 because the alpha particles don't penetrate far.

radiation question

Can someone explain how this radiation thing works in terms of where the particles go? I.e. suppose you have a 1 foot diameter Po-210 sphere. The polonium in the interior of the sphere decays into helium nuclei and some other decay products (lead?). I gather that through some kind of nuclear process, the lead left over after a Po atom has ejected two protons in the alpha particle, somehow creates two new electrons to stay electrically neutral. But where do the helium nuclei go? They don't penetrate to the outside of the sphere. Do they stay inside, like a dissolved gas or something? Does the sphere take on a net positive charge? Also, where does polonium-210 come from in nature (i.e. in uranium ore)? Some kind of decay product from the uranium? That should be mentioned in the article. The po-210 half-life is far too short for any to be left from when the uranium itself was first made in some zillion year old supernova. 67.117.130.181 22:38, 26 November 2006 (UTC)

Questions like that should really be directed to the Science Reference Desk, but here goes: Yes, the decay product from alpha-decay of polonium is lead. No, the post-decay nucleaus doesn't create two new electrons, to the contrary it ejects two of those it had (it lost positive charge in the alphaparticle, so it needs to lose negative charge to compensate). Yes, the alpha-particles (helium nuclei) emitted in the interior of the sphere would get trapped there, or at most be able to diffuse around slowly. Since solid polonium is electrically conducting, the ejected electrons would be able to travel freely through the sphere, and would be attracted to the positively charged helium nuclei and combine with them into neutral helium atoms. (Alpha-decay, by the way, is the process by which all the helium we use in balloons and MRI magnets was formed, deep in the Earth - a very slow process, which is why we won't get any more helium once we've wasted what we have.) The sphere would thus not take on any net charge of either sign. As you point out, polonium (all isotopes of it) has far too short half life for any significant amount to be still around from the formation of the Earth. That polonium is still present on Earth, in minute amounts, is only because it is continally being produced by radioactive decay of more long-lived radioisotopes. In particular, polonium-210 is the second-to-last step in a 14-step decay series by which uranium-238 turns into lead-206. U-238 itself has a half-life of 4.5 billion years, and is therefore still around from that "zillion year old supernova" of yours. --mglg_(talk) 00:36, 27 November 2006 (UTC)

I would agree with mglg, if you were to consider a uranium dioxide nuclear fuel the you should be aware of the fact that some of the fission products are gases. It is normal in used fuel to find that some of the xenon has moved around and has then formed microscopic bubbles which remain in the fuel. Even while the fuel is very hot the gas remains in the solid, on heating up to a temperture far in excess of the operating temperture the gas is released. So I would assume that the helium in a small lump of Po might form some small bubbles if it migrates to where a defect in the solid is, the helium in the bubbles would remain there for a long time unless the solid was crushed and heated. You should be aware that a large lump of Po is likely to heat up a lot so the helium would be lost more quickly, I think that a 30 cm diamater Po-210 sphere would melt due to the self heating. The longer lived Po isotopes would heat up less however.Cadmium

Sources

Most of the article references in the body of the text should be moved to footnotes. Furthermore, many of the facts presented lack any sort of credible reference. --209.189.245.112 13:55, 27 November 2006 (UTC)

References

• Radford Jr. E. P., Hunt V. R. (1964). "Polonium-210: A Volatile Radioelement in Cigarettes". Science. 143 (3603): 247–249. doi:10.1126/science.143.3603.247.
• Bangnall K. W. (1962). "The Chemistry of Polonium". Advances in Inorganic Chemistry. 4: 197–229.--Stone 09:55, 28 November 2006 (UTC)
• Rencováa J., Svoboda V., Holuša R., Volf V., Jones M. M., Singh P. K. (1997). "Reduction of subacute lethal radiotoxicity of polonium-210 in rats by chelating agents". International Journal of Radiation Biology. 72 (3): 247–249. doi:10.1080/095530097143338.{{cite journal}}: CS1 maint: multiple names: authors list (link)
• Rencová J., Vlková A., Čuřík R., Holuša R., Veselá G. (2004). "Influence of heavy metals upon the retention and mobilization of polonium-210 in rats". International Journal of Radiation Biology. 80 (10): 769–776. doi:10.1080/09553000400017911.{{cite journal}}: CS1 maint: multiple names: authors list (link)

superscripts

Can we retain the proper superscripts for isotope references? The entire reason why ²¹⁰Po exists is to prevent the tedious re-re-re-use of things like "Polonium-210" in (for example) encyclopedia articles on the subject. mdf 14:16, 28 November 2006 (UTC)

I have flipped a few isotope references back to the ²³⁸U (etc) forms to be consistent with the rest of the article. mdf 23:33, 29 November 2006 (UTC)

Nevermind. Life is simpler when you just stop caring... mdf 00:06, 30 November 2006 (UTC)

Litvinenko

Do we really need to reference this subject here? Why not directly reference polonium at the article on Litvinenko, leaving this article to describe the physical substance? At best, an entry in "See also" is all that is needed here. mdf 14:19, 28 November 2006 (UTC)

Done. MWS 17:28, 28 November 2006 (UTC)

page protection

Is the page protection really needed? There was repeated vandalism from just one IP, which is now blocked. The person came back under another IP and made just one edit. I think it's better to block that IP if the person comes back, than protect the page. There are several IP's trying to edit the article legitimately and the protection is in the way. 67.117.130.181 08:32, 29 November 2006 (UTC)

Whilst this is connected to a current news item, it may be best to keep that semi-protection. -- Beardo 06:45, 30 November 2006 (UTC)

I don't think that's sufficient reason for semi-protection, which is supposed to be reserved for situations where reverting and blocking vandals is too big a pain, or for certain obscure biographies (not applicable to this article). See WP:SEMI. This page shouldn't really be protected, there seems to have been just one recent vandal, who has been blocked. 67.117.130.181 11:44, 30 November 2006 (UTC)

fatal rat dose

I calculate that the fatal rat dose is 8.72e-9 grams per kg of body weight, based on the 1.45e6 Bq/gm figure in the article. Can someone check the figure and then add it to the article? I can't add through the current article protection. Could also note that for a 100 kg human that would be 145e6 Bq or 0.039 curies, about 8e-7 grams of po210.

"See also Poisons" useful ?

Since 1) Polonium has a section on "Toxicity", 2) the WP article on Poisons does not mention polonium, and 3) the specific poisoning of Alexander Litvinenko has its own WP entry, I am wondering if the section "See also Poisons" is useful for polonium. Lklundin 12:27, 29 November 2006 (UTC)

Arguably not, which is why I just removed it. mdf 12:44, 29 November 2006 (UTC)

Minor Edit

In section ²¹⁰Polonium, "measureing" (sic) corrected to read "measuring". Joegee 18:41, 29 November 2006 (UTC)

Tests

Wouldn't that material be better in the gamma/alpha spectroscopy articles? mdf 23:37, 29 November 2006 (UTC)

Minor Edit

Someone, please fix the misspelled word "platinium" in the middle of the article. I'd do it but the article is in NaziMode(tm) right now and won't let me do my community part. Please delete this afterwards. Thanks ^_^

Could someone please add a few simple lines to the Polonium "Toxic" area, "repacking" the scientific data into a form that everyone else can understand ? Does it take a teaspoon of Polonium to kill a person ? A grain-of-sand sized piece ?

What if terrorists dumped a gallon of it into a City Water resevoir ? The science is nice and all, but it has a purpose other than itself and those that understand it. This stuff is scary and what people really want to know is can we be killed by small amounts of stuff that can be manufactured by any 3rd-world country with a nuclear reactor and a pack of kooks for a government.

Thanks, 64.148.244.230 05:02, 30 November 2006 (UTC)Johnny Faster

Figures are inconsistent

"The maximum allowable body burden for ingested polonium is only 1,100 becquerels (0.03 microcurie), which is equivalent to a particle weighing only $6.8*10^{-12}$ gram"

$^{210}Po$ half-life: 138.376 days

$1100Bq/(1atom/(138.376days*24hours/day*3600s/hour)*6.0221415E23atom/mol/(210mol/g))=4.59*10^{12}g$

The 4.59 attogram contradicts the 6.8 attogram figure from the article. I'm not sure what figure is wrong, so I haven't corrected this. A1kmm 06:34, 30 November 2006 (UTC)

Spectra

I think if we're going to have THREE plots illustrating the attenuated alpha particle spectra from some radioisotopes we should at least make them accurate. The alpha emission energy of an isotope is narrow, as correctly shown by the one graph with sharp peaks, but the broadening of the peaks due to the passage of some of the alphas through a material is not a perfect gaussian around the original peak (like doppler broadening for instance)! The passage of the alphas through a material can not INCREASE their energy, only decrease. So what we SHOULD see is an exponentially decreasing curve toward the lower range of the spectrum with a sharp cutoff at the original emission energy. a cutoff peak. just like beta decays. --Deglr6328 07:44, 30 November 2006 (UTC)

Having three plots seems to be excessive – I've been bold and removed the two broader ones. The text explains that the sharp peaks (as shown) will be broadened (in some fashion) in real lab conditions. Also rearranged the graphics, hopefully, to avoid splitting up the titles too much. -- MightyWarrior 10:54, 30 November 2006 (UTC)

Dear Deglr6328, you are right about the passage of alphas through solid films. I have added the text to explain the broadening that can be seen in liquid sintillation where random events cause a variation in the number of photons detected per decay. Do you know some maths which would give a better approxiation to the shape of the spectra than the gaussian function ?Cadmium

I'm afraid I do not know the function that would describe the shape of the spectrum we are looking for.--Deglr6328 09:03, 1 December 2006 (UTC)

Weighted words?

Under applications of polonium it says, "Killling (former) spies." This seems a bit emotionally charged. If that is to be listed as an application of polonium (which seems reasonable enough) I think it would be better listed under the more neutral wording "assassination."

minor edit 210Po

"A few curies (1 curie equals 37 gigabecquerels) of 210Po emit a blue glow which is caused by excitation of surrounding air." Not necessary to specify an amount. "excitation of electrons of surrounding air" may sound better than what is written. "A single gram of 210Po generates 140 watts of power." I would specify "thermic power" otherwise someone dumb will think it is electricity. Make wiki brackets around "microcuries" "The majority of the time 210Po decays only by emission of an alpha particle, not by emission of an alpha particle and a gamma ray." which means that the nucleus that results from the decay is not excited. I don't know, if that should be mentioned. 80.109.194.224 18:11, 30 November 2006 (UTC)

(It should be noted, that there no such word as "sintillation" in English - the proper term is "Scintillation". Dr. M. Kharatishcili.)

LD50

The toxicity information seems inconsistent to me. LD50 doses are normally in mg per kg body weight, as is the Sv unit (equivalent absorbed energy per kg of tissue). But the article currently reads:

The fatal dose (LD50...) for acute radiation exposure is generally about 4 Sv [21]. One Bq of 210Po ... causes a radiation dose of 0.51 µSv if ingested, and 2.5 µSv if inhaled [22]. ...a fatal 4-Sv dose can be caused by ingesting 8 MBq (200 microcurie), about 50 nanograms (ng), or inhaling 1.6 MBq (40 microcurie), about 10 ng.

I can't make sense of this. An absolute amount of radiation in Bq is translated into a dose per unit of body weight (Sv), which is then translated into an absolute toxic amount (50 ng). I'm not changing the article since I might be misunderstanding something here and I suppose there are plenty of knowledgeable people reading this article these days. Han-Kwang 23:01, 1 December 2006 (UTC)