Toxicity of plutonium

[howardsims]

I have heard that plutonium is highly toxic. Is this stricly due to radiation? Or is plutonium also chemically toxic in the way that arsenic is?

[Dr. Lao]

The issue is somewhat confused. It seems that nearly all the toxic effects of plutonium come from its radioactive nature. From an internet search, I found this at http://www.centurychina.com/wiihist/japarms/pu239.html :
6.2.2.2 Plutonium Toxicity
Although plutonium presumably exhibits chemical toxicity like other heavy metals, this effect is insignificant (in fact, unobservable) compared to its radiotoxicity.
The web site doesn't say its source for this, but it more or less agrees with what I understood and was able to find out from other sites.

The actual toxicity of plutonium compared to other substances is another matter. Ralph Nader calls plutonium the most toxic substance known to man. He also says a pound of plutonium could cause 8 billion cancer deaths. These claims seem to be overblown. According to this site http://www.powerup.com.au/~dominion/ff/p22.htm plutonium is nasty stuff, but not that bad. Doing a few calculations using his data, if a pound of plutonium were inhaled (the deadliest form of entry for plutonium into the body) by a large number of people, 2,267,960 cancer deaths would result. I'm not sure how this compares with other substances but it is clearly not something to mess around with.

[AWB]

Hazards
Because of the high rate of emission of alpha particles and the element being specifically absorbed on bone the surface and collected in the liver, 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. Precautions must also be taken to prevent the unintentional formulation of a critical mass. Plutonium in liquid solution is more likely to become critical than solid plutonium. The shape of the mass must also be considered where criticality is concerned.

[edwino]

According to Richard Rhodes, plutonium is warm to the touch, as it is an alpha emitter. I'd assume he was wearing gloves when he touched it -- in that case the alpha particles would be deflected by the gloves, presumably causing warmth.

Also, it is supposed to have some bizarre physical properties as a metal. I can't remember these exactly, but it was something like it shrinks when heated, etc.

We use uranyl acetate all the time here, and that stuff is pretty poisonous. We use it for electron microscopy, though.

[kanicbird]

[d in the liver, plutonium, as well as all of the other transuranium elements except neptunium, are ]
whats the deal with neptuniun, not having a peridoic table on hand, I think that is between Plutoniun and Uranium - why is it not toxic?

[Hat Doggie]

From what I've heard the radiation in plutonium can't penetrate your skin. If you injest some, however, get your affairs in order.

[ignatiusjreilly]

I'm too lazy to look it up and it wasn't mentioned in Lao's post, but I think that Plutonium has some kind of similarity to iron, or that hemoglobin has some sort of preference for plutonium over iron, and that itself is why it is so toxic. It binds readily with the blood and is distributed quickly throughout the body where radiation can go wild from the inside out.

[Dr. Lao]

ignatiusjreilly, you are right Pu is chemically similar to Fe. From the same place (http://www.centurychina.com/wiihist/japarms/pu239.html) I got my first quote in my first post:Plutonium normally exists in biological systems in the +4 oxidation state which chemically resembles Fe 3+. If it is absorbed into the circulatory system it thus a high probability of being concentrated in tissues that contain iron: bone marrow (which is highly sensitive to radiation), liver, and spleen. Plutonium has a biological half-life of 80-100 years when deposited in bone tissue, essentially permanent. Its biological half-life in the liver is 40 years. Chelating agents may help accelerate plutonium removal. If 1.4 micrograms (0.1 microCi) is deposited in an adult's bones, immune system impairment will result, and bone cancer is likely to develop within several years.So due to the similarity to iron the body will shuttle it to parts of the body that contain iron. It can't replace iron in hemeglobin so it just stays there in the marrow and in the liver until the body can remove it. The half-life in the body is long enough that a significant amount of plutonium stays in the body for a person's entire life after exposure.

[Derleth]

This is a detailed report on toxicity from Lawrence Livermore:
http://www.llnl.gov/csts/publications/sutcliffe/

On that page they say this:

Ingestion of about 0.5 grams of plutonium would be necessary to deliver an acutely lethal dose. (For comparison, ingestion of less than 0.1 gram of cyanide can cause sudden death.)

Which is to say, PuO2, the metal we are referring to here, is toxic but you could do a lot worse.

They also say this:

As we explain below, it is hard to imagine scenarios in which a person would ingest or inhale such quantities of plutonium.

One would hope so.

[Crafter_Man]

Regarding Plutonium: I used to work at a Department of Energy facility here in SW Ohio. I designed precision calorimeters that measured the heat output from radioactive elements (or any exothermic material). We calibrated our calorimeters using Plutonium. How? By picking it up and sticking it in the calorimeter! Of course, the Plutonium was triple-encapsulated in steel.

Side note: Plutonium is a much more convenient heat standard than an electric heater, since there are no wires. Sometimes we would use an electric heater to calibrate a calorimeter, but it was a pain in the ass since you had to take into account heat that was loss via thermal conduction along the four heater wires.

We had more than 10, but less than 100 Plutonium heat standards (I can't tell you the exact number; it's classified). Individual standards ranged anywhere from 0.000001 watts to 120 watts. Once you corrected for the exponential reduction in heat over time, a plutonium heat standard is VERY accurate.

You could usually hold the standards in the palm of your hand with no problem if they were below 1 watt. Above that, they were usually too hot to touch. You really had to be careful with the 60 watt and 120 watt standards, as they were quite warm (they were about the size of a beer can). You had to use tongs and asbestos gloves to handle them.

Again, this was plutonium that was triple-encapsulated in steel. You would NEVER want to handle pure plutonium for obvious reasons.

[manhattan]

During one of the contretemps about plutonium fuel on deep space missions, didn't someone offer to eat as much of the plutonium salt (or whatever the fuel was) as an opponent would eat pure caffein?

Or am I remembering wrong?

[Dr. Lao]

manhattan, the author of the paper at the second link in my first post on this thread (here it is again (http://www.powerup.com.au/~dominion/ff/p22.htm)) offered to do exactly this. Bernard L. Cohen of the physics department at the University of Pittsburgh said he made the challenge to Ralph Nader. He claims to offer several such challenges to Nader and others:I offered to eat as much plutonium as he [Nader] would eat of caffeine, which my paper shows is comparably dangerous, or given reasonable TV coverage, to personally inhale 1000 times as much plutonium as he says would be fatal, or in response to former Senator Ribicoff's statement to inhale 1000 particles of plutonium of any size that can be suspended in air. My offer was made to all major TV networks but there has never been a reply beyond a request for a copy of my paper. This was in response to Nader's claim that Cohen was trying to detoxify plutonium with a pen. Cohen decided to offer himself as evidence of the overblown claims about plutonium's toxicity. The paper I quoted is dated from 1985, I haven't heard anything about the challenge since.

[Crafter_Man]

I wrote to Dr. Cohen. Here's his response:




I haven't looked at that article for many years and I haven't done any more work in the field. But I know no reason why my position should be changed. If you have some such reason in mind, please let me know.

Bernard L. Cohen
Physics Dept.
University of Pittsburgh
Pittsburgh, PA 15260


> Dear Dr. Cohen:
>
> About 11 years ago you wrote a paper titled "The Myth
> Of Plutonium Toxicity." It can be found here:
>
> http://www.powerup.com.au/~dominion/ff/p22.htm
>
>
> Do you still stand by the statements & conclusions you
> made in this paper, i.e. that Plutonium is not nearly as
> harmful as most people (especially the media) would lead
> us to believe?
>
> Just curious.
>
> Thank you,