FMF - Friends of Minerals Forum, discussion and message board

[Tracy]

We've pretty much beaten this topic to death, but I must make a clarification to something which Alfredo wrote: "the human body's natural repair mechanisms would be healing some of the damage as time went by." The body's natural repair systems would not be effective against cancers induced by radiation. Which is not to say that I don't agree with teh majority (and have stated all this previously) that the precautions taken to handle radioactive specimens are overblown. I certainly do. I also said previously that it depends on what type of radiation is being emitted - alpha, beta, or gamma. The nature, amount, exposure route and duration are all important in determining whether to be concerned about one's well-being. All that being said, I have trouble predicting a major health risk from radioactive mineral specimens and water used to soak them.

- Tracy

[nurbo]

Hello,
re Alfredo's posting : I wasnt sure if the LD(50) of 4 - 500000 m/Rem was an instantaneous dosage or over a year, I guess from what Alfredo says its in a single sitting, so to get 400000 m/Rem in one minute from Torbernite you would need 19.67 tonnes of it.

So im not worried about my couple of grams

[alfredo]

Tracy is of course right that once cancer gets started it's too late to count on the body's repair mechanisms.

Theoretically, cancer could get started from any tiny amount of radioactivity, even a single cosmic ray or a single decomposing potassium nucleus in a banana, but in practice the probability is negligible. Likewise for radioactive minerals - If you live in a well-ventilated house, don't breathe in dust, and wash your hands before eating, then the "danger" from radioactive minerals is negligible. In fact worrying is probably more detrimental to the health than the very small amount of radioactivity.

Everyone has a different tolerance level for worry. In my own case, in spite of the "brave" words I wrote above, I do worry about friable dusty radioactive minerals, so I've gotten rid of my carnotite and my tyuyamunite. But I have no worries at all about hard compact primary minerals like uraninite, thorianite, euxenite, samarskite...

[chris]

To complete Alfredo's examples, don't forget that you are radioactive too, some of the C12 carbon constituting the very inner chemistry of human's body being partly replaced by C14 carbon which is radioactive...

Christophe

[Cesar M. Salvan]

I think that people use a mixture between different concepts.

Alfredo refers to STOCHASTIC dose of radiation. At higher dose, higher probability of biological effect (not necessarily cancer). The annual maximum for public is under the limit of the DETERMINISTIC dose: the dose that generate biological effect (this effect could be from dermatitis to cancer and could appear 1 day or 30 years after exposition, depending on total dose, dose rate, radiation type and targets)

Nurbo use the limit of 4000 mSv of dose. This dose is effective dose, on whole body. Is impossible that a mineral could generate those effective dose. In case of TONS of minerals and even small samples, we must take into account the SHIELD effect of the matrix and the uranium. Uranium oxides and uranium metal are effective shields, and even are used in the shielding of plutonium isotopes. As a reference, you could take the limit of 1000 mSv/24 hours: this dose is deterministic and cause sickness (not necesarily the dead!).

The target of our terrific torbernites are the hands, where the limit is higher. All the calculations are referred to the equivalent dose for hands and skin.

Anyway, you could take the limits, buy a dosimeter (usually calibrated to measure effective dose and dose rate) and make your own calculations, taking the limit of 50mSv/y for skin in the public and the limit of 500 mSv per year of equivalent dose in skin or hands for the professionals or the limit of 100 mSv/ 5 years of effective dose in professionals as a reference. These limits are well below the deterministics dose. Also, using the dose rate, we should receive dose rates below 2,5 microsievert/hour. This limit could guarantee that you will not exceed the annual limits even if you work with your minerals every day.
Again, use de dosimeter properly and make your own measures.

The minerals are weak gamma emitters. The radiation emitted by minerals is considered safe. Not only consider the radiation type, also the energy spectrum and the matrix effects.
To receive significative effective doses, you need to purify the isotopes contained in the minerals.

"In fact worrying is probably more detrimental to the health than the very small amount of radioactivity.". This is the best conclusion.
When you see the radiation emitted by isotopes as C60, I 125 or Cs 137, the glowing of pure radium salts or the Cherenkov halo, you feel that the energy, penetration power and range of this radiation is actually terrifying.
After, you realize that to compare this with uranium minerals is like to compare a 1000 W halogen lightbulb with a red LED.

Intelligent protection and common sense, yes. Worrying is not the best option. And, even the weak isotopes, follow the ALARA criterion.

Chris, C14 is a very weak beta emitter and in very low proportion. K40 is one of the main contributors for the radioactivity dose we received every day. K40 is in our body, our food, water and rocks...

[Maxilos]

Hi,

I'm read on the internet something about a connection with radon gas and minerals containing uranium and thorium. Can you confirm this, (mayby) explain it a bit better and how I can avoid it?

Thanks in advance,

Mark

[Jordi Fabre]

Mark,

In an excellent topic "The amount of radioactivity handling specimens is negligible?" the risks of the radioactivity were already discussed. Both topics are close so I added your post to this topic in order to continue that discussion.

Jordi

[alfredo]

Radon is one of the daughter products left by decay of radioactive atoms. Good ventilation in your mineral room is the solution to the problem. Radon collects in badly ventilated homes, and bad ventilation increases other health risks too, not just from radon.

[Maxilos]

So if I put a fan in my room with a hose that runs out my window, it should be fine.

Thanks,
Mark

[Tracy]

...Unless you have a huge collection of uranium minerals all in the same place, you might not even need a fan. Just make sure that the airflow through the room is good. Many of us are exposed regularly to very low levels of radon from uranium deposits in the ground. A few specimens are unlikely to increase your overall exposure in any significant/serious way.

- Tracy

[James Catmur]

Radon tends to occur when radioactive elements decay. So if you live in an area where there is granite or granite derived clays there will be higher levels of radon, naturally. For example:

https://www.ukradon.org/map.php?map=englandwales

These may far exceed what you might get from a few specimens - and if you live is a house in such an area you would need to fit a system to remove the natural radon.

James

[arturo shaw]

In case you have not seen the link Jolyon left in Facebook last Sunday it is this one:
https://xkcd.com/radiation/
(link normalized by FMF)

Cheers!

Arturo

[Matt_Zukowski]

What a great chart arturo. It is good to see Fukushima in context.

[John Medici]

I enjoyed the radioactive specimen discussion. My only background is a grad school course on industrial handling of radioisotopes, and many years of Canadian collecting (mainly betafite, thorite and uraninite)(since 1964). In general, I have had very little worry about handling such material as long as it is treated with respect, for instance avoiding long term exposure and remembering that radon is heavier than air, can accumulate in mineral cabinet drawers and can be carried around long term in the lungs as an alpha emitter. In only a couple of instances, where around 65 pounds of crystals were transported, we decided to average out our exposure by not collecting radioactives for a while. Gilbert G., mentioned by John W., and a long term friend of mine too, probably also had lady luck on his side. The human body has quite good resilience regarding various types of cell damage. One should probably be more worried about the dangers of such activities a driving a car than handling radioactive minerals.

[shep G]

Um...sorry to interupt this party but how about just not touching the stuff that slowly whiddles away your life??? I dont know just a thought. Dont get me wrong this stuff is great and intresting but still....