Comments by "George Reynolds" (@karhukivi) on "" video.

Radon daughters giving off beta/gamma radiation mostly, the half-lives are about 20 minutes. After ten half-lives or about 3 hours the radiation from them will be only 0.1% of the original activity.
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@RadioactiveDrew Yes, high radioactivity = short half-life. Which is why purified uranium chemicals are not so radioactive as the ore, the short-lived daughter products have been removed.
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That is not true nowadays, perhaps in the 1940s during the Manhattan project era when miners were often native Americans who also smoked a lot! It was very difficult to determine if it was the tobacco or the radioactive dust that gave them lung cancer. Nowadays the unions are very up to date with occupational hazard awareness and uranium mines are monitored by several agencies. Miners are also very knowledgeable, (they don't have long beards and use pickaxes these days) and will wear dosimeters and are trained how to monitor their working environment. uranium mines will be highly ventilated and if the ore is really high-grade as in Cigar Lake (Can) they will use remote-controlled mining machinery with no personnel underground at all.
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Drew, the radon daughters don't just deposit on your clothes, they also are inhaled and deposit inside your lungs where the Pb210 emits beta particles for many years (half life 22y) and the Po210 emits alpha particles for about 5 years (half life 4½ months). You need to ventilate those old mines or else wear scuba gear!
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@RadioactiveDrew Inhaling a radioactive gas is a very different scenario to gamma or beta exposure from a solid source. The key is in your comment "hard to detect". The radon gas is producing the alpha emitter Po218 which lodges in the lungs and cannot be detected externally, apart from the gamma-emitting intermediate nuclides Pb214 and the Bi214 which decay rapidly in turn to Pb210. The Pb210 has a long half-life of 22 years and that begins to produce the long-lived nuclides, Bi210 and Po210 that stay there.
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