>
>There is also the point that U-238/U-235 before it is mined is mostly
>sitting underground, presumably somewhere relatively geologically
>stable (or it wouldn't still be there) decaying away where it's not
>really affecting anyone - it's not in our immediate environment.

Also, not all radiation is equal.
Plutonium 239 is an alpha emitter, like AM241 in your smoke detector.
The radiation itself is a helium nucleus, at high speed.
So, it is stopped by a sheet of paper, or a few inches of air.

But, if you ingest it, the alpha particle is like a bowling ball against the molecules near it.  But, the isotopes all behave differently, and have different decay chains.

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