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I bought 5.6 gr of uranium ore. The measured gamma radiation is 1µSv/h, we didn't have the instruments to measure alpha/beta radiation.

EDIT: The gamma radiation was measured at 1cm distance. I also updated the unit of measurement as I had only written 1µSv instead of 1µSv/h.

Gello
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3 Answers3

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With a half-life of 4 billion years, uranium is only very weakly radioactive. In fact, since uranium is a heavy metal, its chemical toxicity is actually more of a danger than its radioactivity. If you touch it directly with your hands, you should wash your hands afterwards. You should not eat it. Apart from that, it is not dangerous.

Regarding the legality: Most countries have an exemption limit for activity below which the permit-free handling is possible. For example in the EU, Council Directive 2013/59/Euratom sets the limit for uranium to $10^4$Bq (including the activity of its daughter nuclides). The exemption limits correspond to the limit values of the International Atomic Energy Agency (IAEA).

wallyk
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Azzinoth
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Assuming the measurement is 1µSv per hour, looking at XKCD's handy radiation chart suggests that it is equivalent to eating 10 bananas or having an arm X-ray. If you were staying around the ore it would be equivalent to living in a place like the Colorado plateau with higher than normal background radiation. So that is not much of a problem.

What would worry me more is the alpha and beta radiation. Alpha is short-range, so as long as you don't eat, inject or inhale the ore things are fine. The beta radiation might be more damaging, but as this answer shows, the risk is pretty minuscule even for more active samples than yours. Finally, there is the issue of radon production. This again seems to be a microscopic factor, although sleeping in the same room as the ore might be unnecessary. See also this page for way more information than you need.

Overall, the ore is as safe as any other heavy metal ore.

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I think different types and samples of uranium ore has different radiation strengths due to the difference in concentration and isotopic composition. However, 1µSv/hour is not considered as strong radiation. I have brought a nuclear radiation dosimeter onto an aircraft several times. At about 10km above the ground, the background radiation is about 0.8-1.5µSv/h as compared to 0.1-0.3µSv/h on the ground. Thus, radioactive heavy metal toxicity is a bigger concern because once it gets into your body, it will not be easily metabolized and removed. As it accumulates inside your body, it will not only chemically toxify but also continuously release radiation directly into your body, causing more harm than most other non-radioactive heavy metals.

Moreover, for long-term storage, I also recommend you to put it in a sealed container due to the volatility nature of all substances.