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Tracy
Joined: 15 Sep 2006
Posts: 551
Location: Toronto
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Posted: Sep 15, 2009 15:01 Post subject: Re: The amount of radioactivity handling specimens is negligible? |
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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 _________________ "Wisdom begins in wonder" - Socrates |
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nurbo
Joined: 23 Sep 2008
Posts: 457
Location: Lancashire
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Posted: Sep 16, 2009 10:02 Post subject: Re: The amount of radioactivity handling specimens is negligible? |
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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 |
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alfredo
Site Admin
Joined: 30 Jan 2008
Posts: 981
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Posted: Sep 16, 2009 11:15 Post subject: Re: The amount of radioactivity handling specimens is negligible? |
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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... |
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chris
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Joined: 12 Jul 2007
Posts: 538
Location: Grenoble
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Posted: Sep 16, 2009 11:59 Post subject: Re: The amount of radioactivity handling specimens is negligible? |
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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 |
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Cesar M. Salvan
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Joined: 09 Jun 2008
Posts: 126
Location: Alcalá de Henares
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Posted: Sep 16, 2009 12:01 Post subject: Re: The amount of radioactivity handling specimens is negligible? |
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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... |
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Maxilos
Joined: 02 Nov 2010
Posts: 191
Location: Boskoop, The Netherlands
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Posted: Mar 22, 2011 10:30 Post subject: Gas |
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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 _________________ "Still looking for the philosopher's stone" => Dutch proverb |
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Jordi Fabre
Overall coordinator of the Forum
Joined: 07 Aug 2006
Posts: 4905
Location: Barcelona
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Posted: Mar 22, 2011 10:30 Post subject: Re: GAS |
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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 |
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alfredo
Site Admin
Joined: 30 Jan 2008
Posts: 981
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Posted: Mar 22, 2011 10:43 Post subject: Re: Gas |
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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. |
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Maxilos
Joined: 02 Nov 2010
Posts: 191
Location: Boskoop, The Netherlands
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Posted: Mar 22, 2011 10:48 Post subject: Re: Gas |
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So if I put a fan in my room with a hose that runs out my window, it should be fine.
Thanks,
Mark _________________ "Still looking for the philosopher's stone" => Dutch proverb |
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Tracy
Joined: 15 Sep 2006
Posts: 551
Location: Toronto
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Posted: Mar 22, 2011 11:11 Post subject: Re: The amount of radioactivity handling specimens is negligible? |
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...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 _________________ "Wisdom begins in wonder" - Socrates |
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James Catmur
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Joined: 14 Sep 2006
Posts: 1351
Location: Cambridge
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Posted: Mar 22, 2011 11:24 Post subject: Re: The amount of radioactivity handling specimens is negligible? |
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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 |
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arturo shaw
Joined: 23 Oct 2009
Posts: 89
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Posted: Mar 22, 2011 12:22 Post subject: Re: The amount of radioactivity handling specimens is negligible? |
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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 |
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Matt_Zukowski
Site Admin
Joined: 10 Apr 2009
Posts: 709
Location: Alaska
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Posted: Mar 22, 2011 20:08 Post subject: Re: The amount of radioactivity handling specimens is negligible? |
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What a great chart arturo. It is good to see Fukushima in context. |
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John Medici
Joined: 02 Mar 2011
Posts: 124
Location: Ohio
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Posted: Mar 23, 2011 00:15 Post subject: Re: The amount of radioactivity handling specimens is negligible? |
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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. _________________ field collector |
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shep G
Joined: 11 May 2011
Posts: 13
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Posted: May 11, 2011 21:37 Post subject: Re: The amount of radioactivity handling specimens is negligible? |
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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.... _________________ ~Shep |
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alfredo
Site Admin
Joined: 30 Jan 2008
Posts: 981
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Posted: May 12, 2011 07:25 Post subject: Re: The amount of radioactivity handling specimens is negligible? |
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I agree with John Medici that driving your car is more likely to bring disaster than handling your uraninites. "Whiddling away your life", as Shep says, is more likely to happen from the grease on your hamburger. Let's not forget that the radiation from even the "hottest" natural rocks is pitifully small compared with that from industrial or medical isotopes. I follow the same rules with ALL minerals, radioactive or not: wash hands after handling, and don't breathe the dust. And my house is well ventilated, even in winter. (I hate stuffy air, and would ventilate even if I didn't have any radioactive minerals.) End of worries. Those who are still panicky about radioactive minerals can PM me to get my address and I'll happily dispose of them for you at no charge :)) |
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Riccardo Modanesi
Joined: 07 Nov 2011
Posts: 620
Location: Milano
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Posted: Aug 09, 2012 04:49 Post subject: Re: The amount of radioactivity handling specimens is negligible? |
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Hi to everybody!
Very interesting discussion! Then we mustn't for get Maria Sklodowska / Marie Curie died true by leukemia beacuse of her continuous exposure to radioactive elements she studied every day the whole day including nights, but it's also tru she died in 1933 at 67, corresponding more or less to 97 or 107 of nowadays! In 1933 a 67 year-old lady was truly old, not like nowadays! And then, she studied radioactive elements continuously every day, not like our collecting uraniferous minerals! There are these two big big differences!
Greetings from Italy by Riccardo. _________________ Hi! I'm a collector of minerals since 1973 and a gemmologist. On Summer I always visit mines and quarries all over Europe looking for minerals! Ok, there is time to tell you much much more! Greetings from Italy by Riccardo. |
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alfredo
Site Admin
Joined: 30 Jan 2008
Posts: 981
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Posted: Aug 09, 2012 06:59 Post subject: Re: The amount of radioactivity handling specimens is negligible? |
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Another huge difference between the Curies and mineral collectors is that the Curies were working with purified elements like radium... many many thousands of times "hotter" than the hottest rock in your collection! |
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Susan Robinson
Joined: 05 Aug 2010
Posts: 163
Location: Hancock, MI
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Posted: Aug 09, 2012 10:48 Post subject: Re: The amount of radioactivity handling specimens is negligible? |
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A curator we once knew worked 3 floors underground for many years in an area with no ventilation and over 1400 lbs. of pitchblende from Port Radium in Canada was stored there. He later died of Alzheimer's, not cancer. _________________ Susan Robinson |
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Maxilos
Joined: 02 Nov 2010
Posts: 191
Location: Boskoop, The Netherlands
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Posted: Aug 12, 2012 04:44 Post subject: Re: The amount of radioactivity handling specimens is negligible? |
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Alpha emitters aren't that dangerous when you keep them inside a box made from a colourless material. Since the α-emitters are made of a big nucleus, so they bump easily into other atoms. That's why they are dangerous. But when something is shielding you from that (not especially lead) it can do almost no harm. The only issue is when you open that box and the radon flows out. You have to open the airtight box from time to time, since pressure is slowly building up from the radon. I haven't solved that problem, yet. Any help is appreciated.
One last question: my only uranocircite specimen from 1x0,8x0,3cm (L x W x H) was cracked when somebody was cleaning my UV- box. I'd like to replace it, but what should I do with my current uranocircite?
Mark _________________ "Still looking for the philosopher's stone" => Dutch proverb |
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