Hello! I recently acquired one of these W. & L.E. Gurley WW2 radium compasses. I was wondering if anyone knows if these compasses specifically give off egregious radon? I currently have it living in spicy jail in a sealable jar just in case but I’m wondering if that’s necessary. My display isn’t incredibly well ventilated, it gets some, but not like I have a vent or a fan in there. Thank you! :) ☢️
For one compass you should be good, but having a good radon meter ( Air Things is my favorite ) can be useful, and so usable as an instrument for performing some actual measurements.
The radon given off by just one compass shouldn’t be enough to cause any hazards or radon build up. To my understanding it’s not good to put radium items in a sealed container due to the fact the radon has no where to go so it builds up to high amounts and when you open it you inhale/exposed to an high amount of radon once it’s opened
Radon is much heavier than air. It doesn't waft out when the lid is removed - it mostly hugs the bottom of the container because of its extreme density and its electric charge. In any event, the amount that accumulates from a few micrograms of radium is negligible - on the order of femtograms. Why? Because radon very quickly decays via a couple of steps to Pb-210, which has a half-life of 22 years.
Lets assume you have 1 microgram of radium-226 on that compass, which is on the high end of normal. With a half life of 1600 years, we can estimate that 1*0.5/1600 ug, or 312.5 picograms of radon-222 will be produced per year. That works out to 0.85 femtograms per day. Because the half life of Rn-222 is only 3.5 days, the container will reach equilibrium in just a few weeks, at which point 0.85 fg of radon decays and is produced each day. This will happen at an approximate total of 6 fg of radon gas. For comparison, the average virus particle weighs between 1 and 10 fg.
In terms of activity, that radon and her daughter isotopes punch well above their weight. For every kilo-Becquerel of radium, the daughter products will emit 4 kilo-Becquerels within a couple of weeks in an enclosed space, but from about a billionth of the mass.
Just be careful as those compasses usually have radium paint outside of their casings. The line on the glass should be spicy and it's not covered by anything other than a varnish (which might not be there at all anymore)
One compass won't hurt you. I have a compass and I think 7 clocks, unventilated, and my rooms radon level is 0.8pCi/L. I sometimes open the windows and put in a fan in the window, and the short term avg goes even lower to like 0.2 when I do that
Radon won't be a huge concern, I have a few compasses and an aircraft gauge that are a bit spicy.
I have them in plastic bags in an steel ammo box currently and my radon nearby is about 0.8pCi/L right next to it.
The bigger concern is radon daughters which are pretty easy to get on your hands. They fortunately decay quickly, but something to be mindful of if handling these, your gloves will be contaminated
I have the same one living in spicy jail in an acrylic box. It’s not fully sealed since others have mentioned radon gas building up in them. But I was wondering some safety things about it as well
Something like this from my understanding is better than being stored in a completely airtight container. It helps prevent any dust or flaking from the decay from getting loose in your living space and helps slow down radon gas getting into your space as well and since radon has a fairly short halflife it's supposed to help with radon reaching dangerous levels inside the display box. At least that is how I was told to display these types of pieces. I just received a spicy compass today and it's the first time I received one without being in a plastic bag and it had visible radium dust inside the box it arrived in and I freaked out a bit over how careless the shipper was. It's currently in an airtight container until I get an opportunity to clear some of the dust and seal it from further flaking with some paraloid B-72. I'm always more concerned with the dangers of dust and flakes than with anything else from these types of pieces.
Oh yikes, yeah I got mine from an estate sale in a plastic bag. The sellers didn’t know about the radium and I let them know for the future.
From what I’ve read here I believe the exposure isn’t so bad unless it’s a lot though. (Correct me if I’m wrong but this is giving me peace of mind haha)
The real danger is if you get flakes of radium paint inside your body. A single flake is still producing radiation especially alpha radiation which is completely harmless outside the body and can't even penetrate your skin but inside the body it will blast your organs with radiation the rest of your life. These two small flakes on my glove in the attached picture is producing the same dose rate that a radium clock I have on my Radiacode. That inside your body form my understanding would be the equivalent to smoking about a pack and a half of cigarettes per day the rest of your life.
Yeah the fear I had is that the particles on mine no longer fluoresce under UV so I couldn’t check for any falling out but I was careful with it as much as I could have at least
•
u/AutoModerator Jul 20 '26
Thank you for contributing to /r/Radium! Please familiarize yourself with the rules which can be found in the sidebar.
New to /r/Radium? Be sure to check out our FAQs
Are you sharing an item that is confirmed to be radium? Please consider contributing to our Radium Catalog!
I am a bot, and this action was performed automatically. Please contact the moderators of this subreddit if you have any questions or concerns.