I was listening to the news this morning and there was mention of distributing potassium iodide to defend against thyroid cancer when exposed to radiation. (They also mentioned this would be effective only for people relatively close to the source of exposure.) The theory behind this is that your thyroid gland uptakes iodine, and if you provide it with enough clean iodine it will not take up the radioactive iodine. I do not remember the context in which this item appears so I can’t describe the source of radiation, but I believe it was something accidentally leaching into the environment, vs. occupational or weapons exposure.
So here’s my question.
Of all the things you would worry about when exposed to radiation, why is everyone so worked up about thyroid cancer? Isn’t this radiation going to cause worse problems than that?
I think that this is seen as a relatively simple way to prevent radioactive strontium 90 (and maybe some other products of bombs) from concentrating in the thyroid and causing problems later on, should you survive the attack. The key word is “easy” – these pills won’t stop radiation or shield you from blast effects (I suspect some people think they will), but if it’s a simple way to cut down on the mean aftereffects of a nuclear accident or attack, why not use it?
It Beats trying to arrange a thyroidectomy in a post-apocalyptic world.
Harmonix: The purpose of iodised table salt is simply to counter iodine deficiency (google: goiter), rather than any radiation hazard. CalMeacham’s answer is correct as far as I know.
I’ve heard that it’s a radioactive isotope of Iodine that it protects you from instead of Strontium, probably the same one my cat got to slow down his hyperactive thyroid. I-131 maybe? The problem is that excess Iodine accumulates in your thyroid, so if you’re taking in lots of it, your thyroid is going to get the brunt of it. And radioactive isotopes of Iodine are a major component of nuclear fallout.
Taking Potassium Iodide tablets is one of the only things one can do to defend from ionizing radiation hazards. It works very well for one particular threat (radioactive iodine release), and then only to protect one organ.
There is little, if anything, one can do for most radiation hazards – limiting exposure in the first place is the best defense – so the fact that you can actually do something is so novel that these pills get a disproportionate amount of attention.
You are right, thyroid cancer is of little immediate concern in case of an exposure. It is also (relatively) easily diagnosed and treated. However, since it is possible to easily avoid this particular threat, it makes sense to do so.