Our local health food store sold out of potassium iodide within two days of the start of the Fukushima problems. There has been a run on potassium iodide tablets all over the world.
Potassium iodide, like other drugs, should only be taken when it is needed. Yet people in Vermont seem to feel they need it to protect them from radiation, when reports say that only very low levels of radiation from Fukushima will reach our coasts.
On the other hand, people may feel it is better to be safe than sorry. What is wrong with taking some pills as a prophylactic?
A lot, it turns out.
The Endocrinologist's Letter
A group of medical societies specializing in endocrinology recently issued a letter explaining why people should not take these pills unless they are actually exposed to significant quantities of radioactive iodine. On March 18, the following medical societies and association issued a statement on Radiation Risks to Health. The associations are:
- the American Association of Clinical Endocrinologists
- the American Thyroid Association
- The Endocrine Society,
- the Society of Nuclear Medicine
Here is a key quote from that letter:
However, KI should not be taken in the absence of a clear risk of exposure to a potentially dangerous level of radioactive iodine because potassium iodide can cause allergic reactions, skin rashes, salivary gland inflammation, hyperthyroidism or hypothyroidism in a small percentage of people. Since radioactive iodine decays rapidly, current estimates indicate there will not be a hazardous level of radiation reaching the United States from this accident. When an exposure does warrant KI to be taken, it should be taken as directed by physicians or public health authorities until the risk for significant exposure to radioactive iodine dissipates, but probably for no more than 1-2 weeks.
That is a pretty impressive list of side effects. Plus, you should only take the pills for a week or two at a time.
Other doctors are also concerned with prophylactic use of KI. As JoNel Aleccia, MSN health writer notes in a recent blog post, doctors are already seeing people with side effects from potassium iodide, and poison control centers are getting calls. The pills are particularly dangerous for people over forty, who run a comparatively low risk of thyroid cancer (if radionuclides were actually present) and a high risk of allergic reactions to KI.
Dr. Edward Maher, president of the Health Physics Society and on the board of the Ethan Allen Institute Energy Education Project, also forward this recently updated KI fact sheet, written in February of this year.
The conclusions are all the same. Don't take KI unless you need it.
And if that isn't enough, remember that K (potassium) is a beta-emitter, like tritium. It is the basis for the radioactivity in bananas. By taking a KI pill, you are deliberately increasing your exposure to internal beta radiation. As noted in my posts about bananas, you are not increasing your exposure by any significant amount. However, avoiding radiation may be another reason to not take the pills. Better to be safe than to be sorry?
Last week, I gave a talk about Vermont and Japan to a local meeting of the American Nuclear Society. The discussion was serious and interesting, and we were lucky enough to have David Ropeik in attendance at the meeting. He is an expert in how people perceive risk. He pointed out that people like to feel they have some control over events. If keeping KI pills in the medicine cabinet makes a person feel prepared, what is the harm in it?
In all honesty, I had never looked at it this way. I presumed if you had the pills, you would take the pills. But maybe not. Maybe having the pills is an insurance policy. In my opinion, the person buying the KI pills is insuring against something that is extraordinarily unlikely to happen. Something it is not worth insuring against. For me, buying KI pills would be the equivalent of buying a special policy that insured me only against the possibility that a plane might fall into my house.
Still, that is my opinion, and obviously other people don't share this view of radiation risk in Vermont.
So my current advice would be: if you are worried about radioactive iodine from Japan affecting you in Vermont, buy KI pills. But for Pete's sake, don't take them!