Yes, I would say so. It would take something like an atomic bomb to spread the radiation wide enough to be troublesome to current residents.

If the plutonium sample has become misplaced, it's probably not going to cause any trouble. A sample that small is unlikely to cause any widely-harmful effects to anything not directly in contact with it. So as long as it isn't inside the local well or underneath someone's pillow... [Was that a joke? It sounded a bit like a joke.]

I apologize for the rambling explanation. It's something I have more experience with than most.