We recently did experiments in school using sources of Radium-226, Americium-241 and Strontium-90. They all had a strength of around 185 kBq. In some of the containers there was only a very thin piece of foil keeping the material inside, or so I was told. Since the experiments I've kind of been freaking out about a possible leak. If anything had leaked, would it have been possible for all the material to come out in a single grain? Because if you accidentaly ingested that grain somehow, I think it would give you a pretty large radiation dose. And if I was working at the table where a leak occured, it might have gotten onto my clothes and I could've brought it into my home perhaps. I know it probably sounds stupid, especially since there is no indication that anything did leak (although they haven't tested them again yet), but I can't help obsessing over it. I'm not worrying about radiation poisoning or anything like that, but it's the possible long term effects like cancer that worry me.