Why poeple should take iodine when in cointact with radiation?

The thyroid absorbs iodine as part of its natural functioning. However, radioactive debris often contains radioactive isotopes of iodine. If the thyroid absorbs these, the radiation can cause damage. The reason people take iodine to protect from the radiation is by saturating the thyroid with nonradioactive iodine, it will not be able to absorb the radioactive isotopes.