atmosphere and that can be taken into the body. that s the concern about a nuclear accident. one big concern is the thyroid gland in particular can take up this radioactive iodine. so this is sort of a simple yet important concept, is that if you get a stable iodine potassium iodine, you flood the thyroid gland with a stable component. even if there is exposure to this radioactive element, it doesn t get taken up by the thyroid because the thiyroid is all full of stable iodine. that s the theory here. it seems to work pretty well. it is just simple potassium iodine tap bletblets. that s not going to work after someone s been exposed or protect people against other effects of radiation poisons or obviously won t protect them against the acute effects, nausea, vomiting, skin changes, effects on bone marrow but it seems to be pretty effective against one of the most disastrous potential complications due to radiation.