EGAC,
With regard to your second paragraph of questions;
Yes, yes and....er well, yes!
Sorry but you have fallen for the spoof part of my answer.
Actually, at least if my schooling and military NBC training were correct, alpha and beta emissions have a very short range and will be stopped by human skin, paper or very definitely by any metal case including a tip cap or blade skin. The problem comes when emitting material is ingested, resulting in the emissions coming into immediate contact with the insides of the body organs. Gamma radiation is difficult to stop (requiring the lead underpants or a few metres of concrete), but it is less harmful than alpha and beta.
Hope this clears up any misunderstanding.
SC