# Are all radioisotopes equally dangerous? [closed]

I'm currently writing an issues investigation on the radioisotope plutonium-239. It's difficult to talk about the dangers of the radioisotope itself, since information on the internet is mixed. Apparently a very small intake of plutonium-239 is lethal, but practically it is unlikely that you will take in that much?

(Just to clarify, I have been considering potential danger to human health and the environment.)

It's confusing, and perhaps best that I bypass that argument. There are many alternative points I could write about, e.g. radiological weaponry, terrorism, unsustainability as a source of energy, nuclear warfare, etc.

## closed as off-topic by John Rennie, CuriousOne, user36790, ACuriousMind♦, Wolphram jonnyJun 13 '16 at 1:21

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• I'm voting to close this question as off-topic because it's about the toxicity of plutonium not physics – John Rennie Jun 12 '16 at 4:28
• @JohnRennie Well, however toxic plutonium is, the reason for that is physical. Anyone answering would have to take that into consideration. – Mad Banners Jun 12 '16 at 4:29
• @JohnRennie See physics.stackexchange.com/q/72496 – Mad Banners Jun 12 '16 at 4:32
• Water is lethal, if you take too much of it... so is air. The question you ask is meaningless. One can work with the most toxic substances and not be in danger if one takes the necessary precautions and one can be killed by a poorly placed brick on a shelf. Just to be frank, the internet does not owe you and, even more so, people who have rather sinister motives any information about how dangerous substances have to be handled. If that is what you want to do for a living, earn the necessary credentials and join the people who have this knowledge. – CuriousOne Jun 12 '16 at 4:50
• @CuriousOne So, just to be clear, you don't know the answer? – Mad Banners Jun 12 '16 at 5:04

Pu 239 can be put in highly toxic radioactive isotopes.

As you know radio isotopes are mostly generated from the radioactive decay reactions and the heaviest material naturally occurring is U238.

Pu239 is mostly created in artificial nuclear reactions. The danger of the radio isotopes is measured by their half lives. Radio isotopes having longer half lives are treated as highly toxic and in this case half life is ~24000 years.

Short lived radio isotopes can be stored in a container and after sometime they are gone and that container pose no radioactive hazard. However long lived radio isotopes pose radiation hazard in case of leak from container. They can contaminate soil, water and air and results in radio toxicity.

Hence you may put radio-isotopes in low toxic (half life few days), mid toxic (half life few years) high toxic (half life much longer than human life) ranges.

Just imagine you put Pu239 in a Stainless Steel container, do you think that the container can hold that isotope for ~50000-100000 years and that's why it is highly toxic.

I hope it will help

EDIT:

you may find these video lectures very useful [1] [2]. If you are interested you can search more by keyword nuclear physics H. C. Verma NPTEL.

Regards

EDIT

@dmckee you are technically right. The toxicity also depends on the type of the radiation they emit (gamma, neutron, alpha or beta), among them neutron is most hazardous.

Any inert molecule is like radioactive particle with infinite decay time (which simply pose no health hazard). But I am talking about the really radioactive compounds, for example mildly radioactive $U^{238}$has ~$10^6$ disintegration per seconds per mole.

The toxicity I am talking about is not per person but for society. If one person dies with short lived isotope only he dies but if long lived isotope is released you may imagine what havoc may happen. It goes inside you and keep on emitting the high energy particles which will result in increased cancer or other deceases in whole area and this will last for thousands of years.

Yes it also depends on actual decay rates, for example thorium, which is even milder radioactive material, is a naturally occurring radio isotope in several places in the world, resulting in natural radioactivity far greater than the acceptable levels worldwide and people are still living there. Over thousands of years they apparently gain higher resistance to the radioactivity than others (I am not sure about it).

I hope I have clarified your objections (at least partially)

• Just curious - what information on the internet is "mixed" about the toxicity of plutonium? Have you found a site which encourages people to sprinkle a little Pu-239 on their corn flakes for breakfast? – user16622 Jun 12 '16 at 11:48
• @user16622 I think you are referring to someones comment over here. I was not in that discussion. – hsinghal Jun 12 '16 at 12:01
• Although the half life of an isotope affects how you need to safely store or contain them, the radiation (strength and type) determines toxicity. You might have a very short half life isotope that is very lethal and another isotope (native uranium ore, for example) with a long half life that you could live on top of for years. How you define danger must include: dangerous to what? The environment or someone handling it? – Mark Ripley Jun 12 '16 at 12:51
• @MarkRipley you are correct, two things are inversely proportional to each other. However when we talk of toxicity we usually talk about environmental toxicity. Ones who handle it are fairly trained and under monitoring. Suppose if a short lived isotope is leaked into a river then it can kill at the most few fish but it will have no effect on the ones who ate those fish, but a long lived isotope will contaminate whole river like slow poison and a huge number of living bodies may have increased risk of cancer. I hope it will help. – hsinghal Jun 12 '16 at 12:59
• This "Radio isotopes having longer half lives are treated as highly toxic and in this case half life is ~24000 years." is simply wrong. The health risk of an isotope is related to it's specific activity (which is generally higher for short half-life materials) and the kind(s) and energy of the decays involved (radiation weighting factors). Very long halflife materials are a particular problem for containment and storage, but if you have the option of being locked in a room with a mole (or gram) of Pu-239 or a mole of Cs-137, you should pick the plutonium. – dmckee Jun 12 '16 at 15:46