ya' know,
The suggestion about badges to show accumulated radiation is such a good, common-sense idea I can't imagine it ever being done.
But these badges would need to measure the radio-activity of substances put directly into the blood-stream... neat trick.
This is a good topic, one I've wondered about as well. Ignorance, is not bliss. looks like I have more home-work to do.
I don't think polonium 210 (the russian spy's end) is something to worry about here, animal of a different color than medicinal radiation.