Something to be aware of: The fact that a radioactive material "is around forever" also implies that it is not very radioactive. You can't make a material that is both intensely radioactive and stays around forever, because it's the radioactivity itself that makes it go away.
Plutonium is indeed not "intensely radioactive." The problem with Pu is that if you ingest it, it stays in your body so you can get enough radiation over time to cause cancer. So you're not going to get radiation sickness from Pu, it's just a very potent carcinogen.
Several populations of people who have been exposed to plutonium dust (e.g. people living down-wind of Nevada test sites, Hiroshima survivors, nuclear facility workers, and "terminally ill" patients injected with Pu in 1945–46 to study Pu metabolism) have been carefully followed and analyzed.
These studies generally do not show especially high plutonium toxicity or plutonium-induced cancer results.[89] "There were about 25 workers from Los Alamos National Laboratory who inhaled a considerable amount of plutonium dust during the 1940's; according to the hot-particle theory, each of them has a 99.5% chance of being dead from lung cancer by now, but there has not been a single lung cancer among them."[95][96] (etc, it's not something you'd want to ingest mind you).
I went to a reactor at INL and their rods were just chilling outside of the reactor, about 50 feet from the controls. Of course, they were highly enriched uranium, so average half life was over a billion years (some was U-238)
With a 24,000 year half life, Pu-239 is sort of on the border of being fairly dangerous, and it decays with an alpha particle, which is good from the standpoint of ionizing radiation but not so good if you are drinking it.
Strontium is worse, btw. Tends to behave like calcium in the body, and you pretty much get radioactive bones. I've heard a lot of talk about it in medical circles over the years (I'm from Romania... not near but not very far from Chernobyl).
That seems more like an oversight of Wikipedia. If Plutonium isn't chemically toxic, that would make it pretty much the only heavy metal (besides gold) that isn't.
Recent research with one of the least radioactive isotopes
of plutonium (plutonium-242, which has a half-life of
376,000 years) indicates that plutonium in the body may
contribute to the development of tumors. In general,
however, plutonium isotopic mixtures that are commonly
encountered in the nuclear fuel cycle, nuclear weapons
programs, or thermoelectric generator applications exhibit
much higher radiological toxicity than chemical toxicity.
(albeit a bit hard to read if you don't parse TeX) seems to say that of 144 beagle dogs who inhaled plutonium oxide, 93 died of bone tumors, 46 of lung tumors and 2 of liver tumors. Although I can't figure out from the abstract what the dose was.
They say it's 0.6-60 Gy. If my calculation is correct, to get a 10Gy dose over ~2.5 years due to the 5.15Mev alphas from Pu239, that would mean they contained 6.7e-8 kg Pu239 / kg body mass, i.e. .06mg/kg body mass. So it's fair to say that it's pretty bad. Unless I dropped a factor N_A or something... ;-)
.06mg/kg is a pretty small lethal dose. That's probably entirely due to the radioactivity. Tetraethyl lead has a lethal dose of something like 1.2mg/kg http://www.inchem.org/documents/pims/chemical/organlea.htm which is 20 times higher. But that's organic lead, which is rapidly absorbed; lead oxide is something like 600 mg/kg, ten thousand times higher than the dose you calculated for plutonium. But, in that case we're comparing the ingested dose to the dose absorbed; you'd have to ingest about 150mg/kg of PuO₂ to absorb 0.06mg/kg of it.
Also, though, the fatal dose of another heavy metal like lead might be lower than the LD₅₀ reported, because LD₅₀ tests normally don't give the experimental animals several years to die.
So, in conclusion, it seems like accurately comparing plutonium poisoning to poisoning by other heavy metals requires more knowledge than I have. Good thing the NRC's on the job.
