Experts point to the dramatically different rates of thyroid cancer and thyroid disease in areas downwind of the 1986 Chernobyl disaster. Areas where potassium iodide was rapidly distributed had a minimal thyroid impact, while areas like Russia and the Ukraine, where there was no potassium iodide distribution, saw dramatic increases in thyroid cancer and thyroid disease.
Children -- including unborn children -- are at the greatest risk of thyroid damage from unintended exposure to radioactive iodine, which if often found in releases of radioactive materials from nuclear reactors.
Now, in the aftermath of the earthquake and tsunamis in Japan, several Japanese reactors were severely damaged, and may be at risk of partial or complete meltdown.
Experts on nuclear energy who were consulted by ABC News have suggested that if one of the reactors has a full meltdown with explosion - such as happened at Chernobyl -- the fallout would typically travel 20 to 50 miles downwind, but could pose a radiation risk to many cities and regions of Japan. There is a small risk that in a meltdown, along with fire or explosions, could send radiation into the upper atmosphere, where it could reach the United States at levels that would not be lethal, but could increase longer-term exposure risk, including to the thyroid.
New reports suggest that Japanese authorities have instituted distribution of potassium iodide to some affected areas.
Meanwhile, those who live in Alaska, and the west coast of Canada and the western U.S. may want to familiarize themselves with use of potassium iodide for thyroid protection, not only in light of the Japanese situation, but also given the prevalence of nuclear reactors in earthquake zones. (Take a look at these maps that show U.S. nuclear reactors, along with earthquake zones.
- 10 Things to Prevent A Thyroid Condition: Keep Potassium Iodide On Hand
- Chernobyl Exposure in Children and Teens Increases Thyroid Disease Risk
- FDA Issues Instructions on Potassium Iodide: Pill Can Cut Risk of Thyroid Cancer
- Protecting Yourself From Nuclear Accident: Should You Stockpile Potassium Iodide?
- FDA Guidance: Potassium Iodide as a Thyroid Blocking Agent
- Disaster Docs Urge Stockpiling Potassium Iodide to Protect Thyroid