> The key question is how the radioactive I-131 gets into your body in the first place. I think its fallout, but I'm not sure. I mean, how could significant amo

> The key question is how the radioactive I-131 gets into your body in the first place. I think its fallout, but I'm not sure. I mean, how could significant amounts of iodine enter your body? You'd have to breath a lot of radioactive dust, and at that point is your thyroid really your primary concern? I-131 is a primary product of fission. With an 8 day half life it's intensely radioactive. And it bioaccumulates in the thyroid. Thyroid hormones triiodothyronine and thyroxine contain iodine. So iodine is a trace nutrient, at 150ug/day.