There are more than 400 nuclear power plants supplying energy worldwide. But along with the benefits of this carbon-friendly energy source, nuclear power also creates radioactive iodine byproducts that can be detrimental to human health if released into the atmosphere. Although there haven’t been many nuclear incidents, Ukraine’s Chernobyl and Japan’s Fukushima accidents show that nuclear accidents can happen.
Recent events have many concerned about potential radiation, and news reports have raised public awareness of how supplemental potassium iodide can protect the thyroid gland after exposure to radioactive iodine. While the supply of potassium iodide is currently limited, the public has time to learn about who would benefit from this supplement and what are considered appropriate dosages.
Question: What are health risks associated with a nuclear emergency?
Answer: The thyroid gland is a critical part of the body that influences almost all vital functions, such as metabolic rate, heart function, brain development and bone maintenance. Radiation exposure to the thyroid might lead to an increased risk of thyroid cancer and benign nodules, which could lead to low thyroid hormone levels (hypothyroidism).
Q: What can be done to minimize health risks?
A: The thyroid gland incorporates the essential nutrient iodine into thyroid hormones; however, this gland can also absorb radioactive iodine. By taking a medicinal dose of iodine in the form of potassium iodide, or KI, the uptake of radioactive iodine by the thyroid gland is greatly reduced.
Q: Who should take KI — and who shouldn’t?
A: Those who are most vulnerable to radioactive iodine are newborns to 18-year-olds and pregnant or breastfeeding women. Older adults are at a lower risk of developing radiation-induced thyroid cancer and may be at a higher risk of experiencing adverse effects from KI ingestion. The risk of side effects from taking a single dose of KI is extremely low. However, those with thyroid disorders have an increased risk of side effects and should get advice from a health professional.
Q: What are the best KI sources?
A: KI comes in many doses. Most common nutritional supplements on the market contain doses too low to protect the thyroid from a radioactive insult. The recommended medicinal dose for those 18 years and older is 130 mg of KI; this includes pregnant and breastfeeding women. The dose for ages 3 to 18 is 65 mg KI; one month to 3 years, 32 mg KI; and newborns, 16 mg KI.
Q: What foods are a good source of iodine?
A: Foods rich in iodine, such as some seaweeds, seafood and iodized salt, contain nutritionally significant levels of iodine, but these amounts are about 1,000 times lower than the medicinal dose needed for protection from radioactive insult.
Remember to always keep up with local public health guidance regarding the dose and timing of KI use.
Alan Titchenal, Ph.D., C.N.S., and Joannie Dobbs, Ph.D., C.N.S., are nutritionists in the Department of Human Nutrition, Food and Animal Sciences, College of Tropical Agriculture and Human Resources, University of Hawaii at Manoa. Dobbs also works with University Health Services.
