Part of my job duties as a emergency planner involve training first responders in radiation safety. So after the Fukushima Nuclear plant emergency I was acutely aware of all the bad advice and rumors floating around about Potassium Iodide (KI).
Now that a lot of that fear has subsided, and we can talk about it objectively and without our eyes bulging out in fear, I want to take a second and talk about what KI actually does.
In the spirit of openness I want to say that I have some KI at my house, and since my in-laws live within 10 miles of a nuclear plant I gave them some also. But I have it out of an abundance of caution than fear. I doubt (and statistics bear it out) neither I nor my in-laws will ever have to use it.
Radioactivity, or the process of an element giving off radioactivity, is a chemical property of a material. Since it is a chemical property, it behaves in predicable manners and we can take precautions against its effects.
In order to survive your body needs certain things. Oxygen and water are the two basic things, but your body also needs chemical building blocks to perform a variety of biological processes. We get these through food. Just like we drink OJ when we are sick to get the vitamin C, or Milk for strong teeth and bones. We need iodide for proper production of thyroid hormones. These thyroid hormones are most closely linked with growth and mental development. Unfortunately not all people receive enough iodide to provide for their bodies’ needs. As a matter of fact, the land around the Great Lakes was known as the “goiter belt” because the soil is particular iodine-deficient, this resulted in higher incidence of goiter among residents. Luckily, iodized salt has almost entirely wiped out iodine deficiency in the U.S.
Since one of the isotopes of “fission products” created by nuclear fission (either in a reactor or in an explosion) is the radioactive form of iodine, it is possible that one of the radioactive products released in either a nuclear power plant disaster or in an attack using a nuclear weapon.
If a person is exposed to radioactive iodine, and their thyroid needs iodine, the body will absorb the radioactive iodine and deposit it in the thyroid. The body cannot distinguish between the radioactive and non-radioactive isotopes.
What KI does is fill the thyroid up with iodine. So if you take it BEFORE exposure to the radioactive iodine, it makes sure there is no room for your body to store the radioactive isotope. That way the bad stuff flows right out of your system as waste.
The problem is that KI is often sold as a “radiation pill”, so that people don’t know its specific use. It only protects against one chemical in a very specific way. It does nothing to prevent damage by radiological exposure, or contamination by materials other than radioactive iodine.
Some people are also allergic to KI, and while some people that are allergic to shellfish are also allergic to KI, it is possible to be allergic to one without the other, and since I am not a doctor, I am not capable of telling you what you are or aren’t allergic to. I would suggest that if you think exposure to radioactive iodine is something you would like to prepare for, you might ask your doctor to test to see if you are allergic to iodine.
You don’t have to be scared of radiation, but you do have to have a little knowledge and respect for what it can and cannot do.