I inherited my grandfather’s WWII compass, and had it sitting around for a long time on a shelf. I recently got a Geiger counter, and find that it’s radioactive. Around 10 microsieverts/hr. Apparently they used radium paint to make them glow in the dark. I can’t just throw it away, but I don’t want it potentially causing a danger to others in the room. Is there some sort of lead lined box I can put it in, or some kind of prevention I can do? Is there anyone experienced with this sort of thing that can offer some advice?
Assuming the majority of the material on it is still Radium, the good news is it’s mostly undergoing Alpha decay - which can be stopped by something as simple as your skin. Depending on the decay chain, there’s also probably a bit of Beta decay in there, for which a strong metal box will probably suffice.
But the real point here is that 10 uSv is the radiation equivalent of being alive for an average day, so brief exposure is unlikely to cause real injury. But here are some things you can do if you’re still concerned:
Limit time exposed to it. It’s okay to take it out to show to friends and family, but otherwise keep it somewhere people aren’t likely to be nearby.
The aforementioned metal box.
Wash your hands thoroughly after handling, and/or wear gloves. It’s unlikely, especially if the radium-painted parts are under glass, but possible that radioactive materials could end up on your skin. Washing hands should prevent this.
If you’ve heard of the “Radium girls”, the thing that really made them sick is that they were licking radium-coated paintbrushes, causing radioactive material to end up inside their bodies. Since (I presume) you’re not licking the compass, you’re much less at risk.
Knowing the dosage is a day’s exposure, and only if you expose yourself to if for an hour, makes me feel much safer about taking it camping once in the be 90s. In general, no one touched it for fear of breaking it.
We’re keeping it in the garage on a shelf, next to a window from now on. With a label.
Thank you!