Assertion: thorium | /r/CapableOf | remain intact
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Source sentences:
text: A study in 1981 estimated that the dose from using a thorium mantle every weekend for a year would be 3–6 microsieverts (0.3–0.6 mrem), tiny in comparison to the normal annual background radiation dose of around 2.4 mSv (240 mrem), although this assumes the thorium remains intact rather than airborne.