Definitely interesting to see your sievert readings. I found this article that outlines similar concerns about radium. Since you have real-world data to back up your concerns, just move the watch on. No style should be worth the concern or real risk of cancer.
If you are concerned about radon, you should buy a radon detector, they are inexpensive. And depending on where you live, you may have a high risk of naturally occurring radon in your living space, so testing is a good idea even in the absence of vintage watches. I have a radon detector, and have used it to test radon levels in various parts of my house, as well as in the drawers and boxes where I store my watches. I've published the results elsewhere.
But again, let’s not forget about the possible benefits:
Seriously, I am mindful of the dangers associated with the buildup of radon gas from a collection of radium dialed watches stored in a confined space. The same goes for the inhalation of airborne particles of disintegrated radium lume. Hint: leave the servicing of these watches to a professional. Both of these risks are something that can be anticipated and planned for. I am much less concerned with radioactive exposure associated with the judicious wearing of radium dialed watches in rotation with other watches.
The dosimeter I have (I called it a Geiger counter) covers that off I think.
Thank you. This is interesting, and it’s absolutely the radon issue that I was more concerned about. Lots of people tend to focus only on the alpha particles and how you would need to breath in or ingest the radium dust itself to cause an issue, when it’s actually much more complicated than that. As I mentioned I literally tested this on a shelf with a Geiger counter a while ago, and I’ve just rerun some tests. Now I remember why I was concerned…
I attach the photos, but as you can see, immediately in front of the dial (where you are unlikely to be, unless you fall asleep with your watch on?), it goes off the scale and records something over 9.99 micro Sieverts per hour. Measured from behind the watch case (ie your wrist), the dose is 2.18 micro Sieverts per hour. Finally, six inches in front of the face, it’s 1.55 micro Sieverts per hour.
As can be seen from the final image “How much is dangerous” which came with the Geiger counter, it states that 1.25 micro Sieverts per hour gives you a real risk of cancer if exposed for a year. That’s much below what your wrist would experience, and who knows how long you’d have to be near the face for it to be a concern.
Anyway, hopefully someone will find this helpful, and from real-world data.
And just to provide an interesting comparison, exposure while flying at commercial altitude (35k) is approximately 3 micro Sieverts per hour). So it’s reasonable to think about wearing that watch for a few hours as equivalent to time on an airplane based on your readings. Obv not accounting for radon exposure, but that should be minimal if you don't keep it in an enclosed space.
Great point. And of course depending on how much you wore the watch etc, but bearing in mind I was wearing it all day, and putting it on my bedside table at night, ignoring the radon and night exposure, that’s a solid 15 hours a day easily. So some quick maths means that it’s on my wrist for 105 hours per week, and so 5,460 hours per year. Pilots (in the UK) are allowed a maximum of 1000 hours flying time in any 12 consecutive months( https://www.caa.co.uk/newsroom/blogs/regulating-pilot-hours-and-combatting-fatigue/)). The risk of radiation exposure to pilots and crew is well documented, and so that’s another real world example of why I am right to be concerned about wearing my watch full time again any time soon!
There are differences between flying (where the radiation is exposed to your whole body) and an equivalent dose being focused (on a wrist).
Can anyone explain why the readings were so high? Unless there are holes in the case, alpha particles should not be causing those numbers.
Well, keep in mind that when radium emits an α particle, it stops being radium and becomes radon. It's quite possible that radon gas could be escaping from the case, even if it was fairly well closed. If so, you would be able to measure alpha particles (and radioactivity in general) outside of the case with some consistency because radon has such a short half life.
Just a possibility. I had a bit more time to think this through since my last response here and this would make sense to me, but of course I can't guarantee it is what has happened/is happening.
I thought that sensor was not effective for radon gas?
It all comes to personal preference and if it is to make you sick from worrying over the sickness from the radium, sell it off to someone that appreciates it for what it is without this fear and buy one without lume.!
