Had seeds put in a few years back, About two years after, the wife and I were crossing back into the US from New Brunswick into Maine at an obscure crossing up north. The agents, out of boredom probably, had us unpack our bikes, camping load and all for inspection. As we were repacking in the customs parking lot, one of the agents came over and asked if either of us had radiation treatment because they had picked up a reading from us. Amazing since the seeds are pretty much done by well before then. I feel better about anyone trying to smuggle radioactive stuff in after that.