FMF - Friends of Minerals Forum, discussion and message board

[Tracy]

My radiation science is rusty, but something seems not quite right here. I thought that radon was a hazard because upon inhalation is can decay into an alpha emitter which lodges in lung tissue and gives off radiation, along with its other decay products?

Also, for radon to build up in an enclosed space, you need to have radon gas pouring into it. I doubt that is the case for any mineral specimen that is radioactive, I don't see these as radon gas generators. If I'm wrong and they are, you're not necessarily keeping yourself safe by opening the box and letting the radon gas out...

- Tracy

[Maxilos]

Radon is indeed hazardous because of the possibility of getting inside your lungs. Inside your lungs the radon atoms are very close tissue which gives an "opportunity" for the "big" Alpha radiation to bump into other atoms. Also the decay-products are radioactive and quite toxic, as for any heavy radioactive material. Don't forget that the half-life of most natural radioactive elements is quite long. Radon is also hazardous when just in the air. Even in the air it is radioactive. Since it is heavier than air, is it not that healthy for you.
Those plastic boxes can serve as a small security measure for a-radiating minerals.

As for the second point, I believe you are correct there.

Mark

[Riccardo Modanesi]

Hi to everybody!
Half-life of a radioactive element is really important, but not always decisive. A good example is 14-C, which has a hal-life of some 5000 years but it isn't so dangerous for our organism, and the contrary example is 131-J (Jodium), which has a 30-days half-life, but it is seriously dangerous for our tyroid, frequently causing cancer.
Greetings from Italy by Riccardo

[Tracy]

Sorry, but I think this topic is getting derailed. Harm from radiation is influenced by:

- the intensity of the radiation (alpha, beta, gamma): how deeply does it penetrate tissue

AND

- the ability for tissue to be irradiated: how can the radiation come into contact with cells

All points made are correct but incomplete. I-131 (which has a decay half-life of 8 days, not 30) can cause thyroid cancers ONLY if it is taken up by the thyroid, which is often the case with iodine in the body. Radon can cause lung tumors ONLY if it's inhaled, It is a gas which has a half-life of 4 days and is a beta-emitter, but degrades into solid-particle alpha-emitters which can lodge in the lungs and will eventually decay to other alpha- and beta-emitters which can reside in tissues for years. Alpha-emitters have the highest energy, but their energy has LESS ability to penetrate tissues (causing mutations leading to cancer along the way) than beta- or gamma-emitters. The entire process with its complexities has to be considered; risk = the degree of hazard + the potential for exposure, and "the dose makes the poison."

If I had a choice between radon gas and solid I-131, I'd choose I-131 because I could put it safely out from reach (like in a jar) and make a point of not eating or otherwise absorbing it. Radon gas, on the other hand, is harder to control because it's tough to keep a gas from moving around and getting inhaled without ventilation control. Radon is also invisible, whereas I-131 is not. However, I might reconsider if it were a mountain on !-131 versus a small puff of radon gas.

It's also worth noting that I-131 in small quantities is used in diagnostic medical procedures.

This is way off track, aren't we supposed to be talking about rocks?

- Tracy

[Riccardo Modanesi]

Hi to everybody! Hi Tracy!
I apologize I gave a wrong datum about 131-I. For the rest, your discussion is very interesting. I just made a comparison between a potentially dangerous radioactive element having a half-life of some days, and a not seriously dangerous radioactive element having a half-life of some thousands years! I think you all understood what I mean.
Greetings from Italy by Riccardo.