Japanese Radiation: A Risk to Your Thyroid?

 The release of radiation from Japan’s Fukushima Daiichi nuclear plant, which was damaged by the devastating earthquake and tsunami that hit earlier this month, has triggered mounting concerns around the world.

Just how dangerous is the radiation release and are those in the United States at risk?

The damaged nuclear plant has released radioactive iodine, including iodine-131, into surrounding areas. Those in the immediate vicinity could face serious health repercussions, as exposure to radioactive iodine can lead to the development of thyroid nodules and thyroid cancer, among other health problems.

As for the radiation traveling to the United States, so far this risk appears to be minimal. The radiation will be diluted by 5,000 miles of ocean, rain and sea spray when it reaches U.S. shores, hopefully making it of little consequence to human health. To date, the U.S. Environmental Protection Agency (EPA), which has been monitoring radiation levels across the country, has noted radiation levels slightly higher than normal but “still far below levels of public health concern.”

The radiation scare has also sent many scrambling for potassium iodide (KI) pills, which help protect your thyroid from radioactive material. Your thyroid is particularly vulnerable to radiation poisoning as it actively uptakes iodine from your blood to make thyroid hormones. If you’re exposed to radioactive iodine, your thyroid will not know the difference and will take in the radioactive substance.

By taking potassium iodide (a stable form of iodine), you can essentially flood your system with so much iodine that your body will have no need to uptake the radioactive form, thereby protecting your thyroid from the damaging effects.

The U.S. State Department has given KI pills to U.S. personnel residing in the Japanese danger zones, but so far there appears to be no need for U.S. citizens in the United States to take the pills as a precautionary measure. In fact, taking potassium iodide unnecessarily is not a good idea, as it can lead to serious side effects including even hyperthyroidism or hypothyroidism.

The American Association of Clinical Endocrinologists, the American Thyroid Association, The Endocrine Society and the Society of Nuclear Medicine also released a joint statement advising against the use of prophylactic KI at this time:

“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.



With radiation accidents, the greatest risk is to populations close to the radiation source. While some radiation may be detected in the United States and its territories in the Pacific as a result of this accident, current estimates indicate that radiation amounts will be little above baseline atmospheric levels and will not be harmful to the thyroid gland or general health.



We discourage individuals needlessly purchasing or hoarding of KI in the United States. Moreover, since there is not a radiation emergency in the United States or its territories, we do not support the ingestion of KI prophylaxis at this time.”

We’ll be keeping an eye on this issue as time goes on, so stay tuned to the blog for further updates.