Most food is irradiated, yes. Prevents potatoes from sprouting, sterilizes tons of food, etc. I am very familiar with that, but didn't realize that radionuclides were ever-present in fertilizers.

I grow my own tea, and use fertilizer. Am I at risk for the same issues after processing the leaves? Additionally, would this then extend to cannabis as well? While they aren't leaves, I'm assuming that radium would end up there as well if in the fertilizer.

I guess what I'm trying to say is what is it specifically about tobacco - is it the mechanism of intake of the tobacco plant specifically, is it a property of all plants and fertilizer, or is it only a property of specific parts of all plants?