|What the readings mean|
|Re: Uranium Glass Beads - some info and data -- Rosanna||Post Reply||Edit||Forum||Where am I?|
The average reading was 0.041 mrem/hr. If a necklace had 30 beads of 2.5g, the dose would be 0.041 x 30 = 1.23 mrem/hr from the necklace. If you use more or less beads you can calculate a new value accordingly.
To make sense of this number, first note that radiation safety is generally described in terms of total rems exposure per year. Natural exposure from inhaling air, drinking water, eating food, and radiation from cosmic rays and from the earth amounts to 300 mrem in a year. Additional radiation comes from things like a mammogram (40 -42 mrem), a chest xray (6-10 mrem) or airplane flights (cross-country gets you 3.5 mrem). CT and CT/PET scans run pretty high - 1000 mrem and 2500 mrem respectively. For another data point, a worker in a radiation business has a limit of 5000 mrem per year, with a total of 10,000 mrem over 5 years. Note that these figures don't depend on what type of radiation it is - alpha, beta, gamma, xray, are all treated as radiation exposure.
So to get a dose equal to a mammogram, you would have to wear your beads for 40/1.23 = 32.5 hours.
Here's what I did for my own beads that I found had UG - I put a note under the 5 necklaces with a reminder to limit wearing to 40 hours per year, since I don't have a lot of larger beads on these strands.
The 40 hours is super conservative. Unless you happen to have a year where you get a number of CT scans and dozens of airplane flights, I wouldn't worry about wearing the beads for several hundred hours or more. Or if you have skin cancer or some other skin condition on your chest and neck, I'd be extra cautious.
So in summary, check your beads for UG with a black light. Then use some common sense with regards to number of hours wearing them, and don't eat or grind them.
Note - there are reports of UG glassware with very high uranium content - up to 25% instead of a more typical 2%. I have no idea if there are beads made with the higher content. But you can see from the calculations, that even if your beads have ten times the uranium content, limiting your wear to a sensible duration every year will still put you below something like a CT scan in exposure. And the exposure is only to your skin, not internally like the CT scan.
Hope this helps!