Q&A: Radiation risks and potassium iodide
Californians concerned that radiation from damaged Japanese nuclear power plants could reach the U.S. have rushed to protect themselves by stockpiling potassium iodide. Times reporter Molly Hennessy-Fiske talked to Dr. Glenn Braunstein, director of Cedars-Sinai Medical Center’s thyroid cancer center and chair of the department of medicine, about the potential risks and benefits of the drug.
Question: How does potassium iodide work?
A: The thyroid gland requires iodine to make thyroid hormone. If one is exposed to radiation, to radioactive iodine, it is taken up by the thyroid and can cause cancer. This is especially a problem in children and adolescents that are exposed, because their thyroids are still growing. The iodine in potassium iodide is what we call “cold,” because it’s not radioactive. The thyroid gland gets saturated with “cold” iodine and can’t absorb the radioactive iodine.
Q: Has potassium iodide proved effective in protecting people from radiation during past disasters?
A: After Chernobyl, with the winds carrying a lot of radioactive iodine downwind, Belarus and Ukraine got a big dose of it and they didn’t have any protection. They saw a hundred-fold increase in thyroid cancer. Poland also got exposed to the cloud but handed out potassium iodide, and there wasn’t an increase in thyroid cancer. So it is effective, but one has to have a substantial danger, which there isn’t here.
Q: Should people in California take potassium iodide now to protect against nuclear radiation from Japan?
A: Absolutely not. The likelihood of having a problem from the Japanese nuclear power plant is very low.
Q: What are the risks associated with taking potassium iodide?
A: If you take it too early, it’s less likely to be effective. You really want to take it 12 hours before the exposure and you want to take a tablet a few days in a row. It does have potential side effects. About 8% of the population have auto-immune thyroid disease — these individuals are very susceptible to getting large iodine loads. It could lead to an imbalance in their thyroid. About 1% of people get rashes; a number of people get nausea and vomiting, primarily from the taste — it’s got very bitter taste. Rarely, there will be allergic reactions. It’s not innocuous. The risk far outweighs the benefit.
Q. What about keeping potassium iodide on hand as a precaution?
A: If they have it on hand and an air raid siren goes off, then they can take it and they don’t have to go to a distribution center. Last year the residents around San Onofre [nuclear power plant] were offered two free pills of potassium iodide, and then there are big stores of potassium iodide around San Onofre in case there’s a problem. There’s nothing wrong with having it — it’s just that there’s no reason they have to panic and run out to get it now. It really galls me to see the profiteers on the Internet taking advantage of people’s fears.
Follow Molly Hennessy-Fiske on Twitter @mollyhf
Photo: Potassium iodide pills. Credit: Justin Sullivan /Getty Images