Iodine and Radiation

Mar 28, 2011

By Trevor Shewfelt, Pharmacist at the Dauphin Clinic Pharmacy

The potassium iodide tablets are in the basement of the curling rink. Everybody knows that. In the event of a nuclear incident every one will congregate there and the potassium iodide will be distributed as required. What? Didnt everyone grow up next to a nuclear reactor? When I was a child in Pinawa, MB the officials didnt consult me on all their emergency plans, but I do remember being told the potassium iodide was in the basement of the curling rink. Thankfully we never had to use them. The people of Japan werent so lucky. The recent natural disasters in Japan were horrible. An earthquake, and then a tsunami killed thousands. Whole towns were wiped off the map. Thousands of people are still missing. Then, too top it all off, there are half a dozen reactors which sustained damage from the earthquake and tsunami. The radiation leaks from these reactors are a serious concern for people in Japan. However, the radiation is not a problem here in Manitoba. You dont need to go the pharmacy and buy potassium iodide.

Why are the people on the news talking about potassium iodide in Japan? Why are people in BC wrongly buying up all the potassium iodide in that province? Lets start by talking about what iodine does in the body. Iodine is essential for life. It is important in brain development, hormone production and in the thyroid. Iodine occurs naturally in sea water, but as you get farther from the ocean, there is less and less of it. Historically, much of Canada was considered to be in a Goiter Belt. Historically people in a Goiter Belt had more thyroid problems that usual and more goiters or swollen thyroid glands in their throats. This is because in the past there wasnt much iodine in the food or air in the middle of the continent. Iodine is necessary for the thyroid to function properly. Since Manitoba is so far from the ocean it is tough for iodine to get here. People who live on the coast usually have lots of iodine in them. A lot of iodine comes from sea water spray that ends up in shore plants and soils. Iodine is also high in seaweed and seafood so when these are eaten, the person gets their much needed iodine.

So what does iodine have to do with a nuclear accident? After the reactor accidents in Japan, some radioactive material was released. There would have been many different types of radioactive materials released. Radioactive iodine, also known as Iodine-131 is of particular concern. Chemically Iodine-131 is identical to iodine. So the body will absorb it from food and water, because the body needs iodine. If the body absorbs it, it could be transported to the thyroid gland. If radioactive iodine stays in the thyroid, it could lead to thyroid cancer. This is where potassium iodide comes in. When potassium iodide is administered at the correct dose it prevents radioactive iodine that people might inhale or ingest from getting into their thyroids and causing damage. The potassium iodide floods the thyroid with non-radioactive iodine. This prevents the radioactive iodine from staying in the already full thyroid and the radioactive iodine leaves the body in the urine. In a contaminated area, the people at the greatest risk are infants and children. Unless the contamination is very severe, it is often recommended that those over 40 dont get treated with potassium iodide at all.

Now here is the important part. Japan is literally on the other side of the world from here. The radioactive iodine from the damaged reactors is being produced in minute amounts. By the time it could migrate all the way here in the air it would be so dilute as to be non-existent. Remember all iodine is naturally scarce here in the middle of the continent. What if a molecule or two of radioactive iodine does get here and you do absorb it, what then? You still dont need to worry. If against astronomical odds, odds far greater than winning the lottery, you absorb a molecule of radioactive iodine it wont hurt you. In fact a small amount of naturally occurring iodine is Iodine-131 or radioactive anyway. Your body always had a chance of running into a few molecules of radioactive iodine.

What is wrong with stocking up on potassium iodide tablets? I hear the people in BC and California are buying so much of it the pharmacies cant keep it in stock. Why shouldnt I go buy some? First you are buying something that is of no use to you. Potassium Iodide tablets are only useful to those who are going to be exposed to radioactive iodine in the very near future. Second is that like all other medications, potassium iodide has potential side effects. It can cause iodine toxicity. This can range from mild metallic taste in your mouth to sore teeth and gums and all the way up to thyroid damage. It is even scarier to think that well intentioned people may poison their kids with iodine mistakenly thinking they were protecting them.

So dont spend your money on potassium iodide tablets to protect from radioactive iodine that isnt coming. You are not going to help yourself and you might cause some harm. Instead go the Red Cross website and put that money towards Japan relief.

Canadian Red Cross

As always if you have any questions or concerns about these or other products, ask your pharmacist.

The information in this article is intended as a helpful guide only. It is not intended to be used as a substitute for professional advice. If you have any questions about your medications and what is right for you see your doctor, pharmacist or other health care professional.

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