I actually don't think it's possible. If I remember my OPWACHEM course correctly, if the media you're thinking of did wash onto the yard worker he'd have been s

I actually don't think it's possible. If I remember my OPWACHEM course correctly, if the media you're thinking of did wash onto the yard worker he'd have been severely injured by radiation exposure, and not just quickly bumped up to his maximum lifetime allowable exposure. It is indeed extremely nasty stuff.