Potassium Iodide

Potassium Iodide is a chemical substance having formula KI, containing a positively charged Potassium ion and a negatively charged Iodine ion. Potassium Iodide is the ingredient added to edible salt to make it iodized salt. It is also used as protection against exposure to the radiation from nuclear power plant.
In the event of a nuclear power plant meltdown (or other radioactive event), two radioactive forms of Iodine are released: I-129 and I-131. While I-131 is radioactive, it has a very short half-life of 8 days. This means that I-131 will be completely cleared from the environment in a matter of months. Whereas I-129 is highly radioactive and has a half-life of 15.7 million years after a nuclear power plant meltdown, it will stay in the environment for a very long time.
The human thyroid will absorb Iodine indiscriminately. If radioactive isotopes of Iodine are inhaled or consumed, the thyroid will take up the isotopes. This radiation is likely to cause cancer, particularly for infants and children. People over the age of 60 are at a lower risk from developing thyroid cancer from radioactive Iodine isotopes
Many scientists believes that the human thyroid will only take up a certain amount of Iodine & by giving people Potassium Iodide (a safe version of Iodine), the thyroid fills its receptor sites with the safe version of the element. When the individual is exposed to the radioactive Iodine isotopes, the thyroid cannot take it up, as its Iodine receptors are filled with Potassium Iodide. In this way, the radioactive material passes safely through the body without being taken up by the thyroid. Potassium Iodide pills work best when used within 3-4 hours of exposure. Taking Potassium Iodide pills when there is no need can cause serious health problems, particularly for pregnant and lactating women