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Potassium Iodide, Radiation and Thyroid Risks

  • Synopsis: Published: 2014-01-08 (Rev. 2017-06-28) - Information regarding Potassium Iodide (KI) a substance that floods the thyroid with iodine preventing radioactive iodine from becoming absorbed. For further information pertaining to this article contact: Thomas C. Weiss at Disabled World.

Main Document

"Potassium iodide protects only a person's thyroid, yet it is the organ at highest risk from radioactive iodine."

A person's thyroid gland needs iodine to produce hormones that regulate their body's metabolism and energy. The thyroid absorbs available iodine from a person's bloodstream. The thyroid gland is unable to distinguish between stable, or regular, iodine and radioactive iodine and will absorb whatever it can. In babies and children, the thyroid gland is one of the most radiation-sensitive parts of the body.

The thyroid gland is a butterfly-shaped endocrine gland, usually located in the lower front of a person's neck. The thyroid's job is to make thyroid hormones, which are secreted into a person's blood and then carried to every tissue in the person's body. Thyroid hormone helps a person's body to use energy, stay warm, as well as to keep the person's heart, brain, muscles, and other organs working as they should be.

The majority of nuclear accidents release radioactive iodine into the atmosphere and may be absorbed into a person's body. When thyroid cells absorb too much radioactive iodine, it may cause thyroid cancer to develop a number of years after a person is exposed. Babies and young children are at highest risk, which is much lower for people who are over the age of 40. Thyroid cancer seems to be the only form of cancer whose incidence increases after a radioactive iodine release. Potassium iodide protects only a person's thyroid, yet it is the organ at highest risk from radioactive iodine.

Potassium Iodide or, 'KI'

Potassium iodide (KI) is the same form of iodine used to iodize regular table salt. KI floods a person's thyroid with iodine, preventing radioactive iodine from becoming absorbed. If it is taken at the proper time, KI protects a person's thyroid from radioactive iodine from all sources; food, air, water and milk. KI is a non-prescription drug that people have the ability to purchase over the Internet and at some pharmacies. KI is made in both liquid and pill forms. KI products approved by the Food and Drug Administration (FDA) include:

  • Iosat Tablets
  • ThyroSafe Tablets
  • ThyroShield Solution

Appropriately packed, KI's shelf life is at least 5 years and possibly as long as 11 years. If you take a very old KI pill it might not work as it should, although it will not harm you.

Following the 1986 Chernobyl nuclear accident, shifting winds blew a radioactive cloud over Europe. As many as 3,000 people who were exposed to the radiation developed thyroid cancer over the next decade. The majority of the people affected were babies or young children living in Belarus, Ukraine, or Russia. The region of excess risk extended up to a 200 mile radius from Chernobyl. Poland distributed KI to greater than 95% of children within 3 days of the accident and does not seem to have had an increase in thyroid cancer.

Since children are at the greatest risk to exposure to radioactive iodine, KI should be available to every child. Due to the risks posed to a developing fetus, women who are pregnant should also take KI in the event of a nuclear accident. Adults experience a lower risk, yet may still benefit from taking KI. Along with KI, priority should be given to evacuation, sheltering, and avoiding contaminated food, water, and milk. KI should not take the place of other protective measures.

When to Take KI

KI fills a person's thyroid cells and prevents the gland from absorbing radioactive iodine for around 24 hours. People should take one dose per day while they are being exposed to radioactive iodine until the risk is no longer present. KI should only be used under instruction from local health authorities.

Not every radioactive release includes the radioactive iodine that might cause thyroid cancer. A, 'dirty bomb,' for example, is not likely to contain radioactive iodine because it has a short half-life. A dirty bomb is a conventional bomb mixed with radioactive material and is designed to explode, spreading radioactive isotopes and contaminating a large area. Health authorities can determine which radioactive isotopes are released during a nuclear event. If radioactive iodine is released, health authorities will advise on when and for how long a person should take KI.

Who Should not Take KI

Millions of people have taken KI, yet few serious side-effects have been reported. The only people who should not take KI are people who have experienced a serious allergic reaction to iodine. During a nuclear emergency, the benefits of KI far outweigh any potential risks. Adults over the age of 40 do not need KI at all unless they are exposed to very high levels of radioactive iodine.

People with thyroid disease can safely take KI pills in the dosage recommended. If a person takes KI long enough, it might cause temporary hypothyroidism. The amount of time is different for each individual. Prolonged treatment may become a serious issue for children who are very young. Such children need to be seen afterward by a health care professional. People with Graves' hyperthyroidism, or with autonomous functioning thyroid nodules, should also be seen by a health care professional.

Most People Survive Thyroid Cancer

Generally, 90% of people survive thyroid cancer. The post-Chernobyl cancers have been aggressive and have been unusual in affecting children under the age of 10. Thyroid cancer survivors always remain at risk for recurrence and need lifelong medical care. People who were exposed to radioactive iodine from the Chernobyl accident, but have not developed thyroid cancer, remain at risk for the remainder of their lives and have to continue being tested. The demands of regular testing and care for this sizable population are placing a heavy burden on both those affected and the health care systems that treat them.

Additional Information

KI is an adjunct to evacuation, sheltering, and avoiding contaminated food, water, and milk. KI is not intended to take the place of any other protective measures. KI is unlikely to somehow, 'lull,' people into a false sense of security. Local authorities recommend that people leave the vicinity of a nuclear emergency as rapidly as they possibly can. People are being taught that KI is simply a supplement to evacuation.

Unfortunately, nuclear releases are unpredictable and traffic jams are very likely to delay speedy evacuations. People should take their KI before they evacuate and follow the instructions provided by local health officials. The Department of Health and Human Services has recommended distribution of KI to people living within 10 miles of a nuclear plant.

The American Thyroid Association recommends that KI distribution not be limited to 10 or 20 miles in radius. No one has the ability to predict how far a radioactive iodine cloud may spread. After Chernobyl, higher than expected rates of thyroid cancer were discovered more than 200 miles away from the accident itself. Therefore, no one can predict just how far from a nuclear plant the United States should distribute KI if it is to protect every person who may be exposed to radioactive iodine. Since there is no correct answer, the American Thyroid Association recommends 3 levels of coverage, determined by distance from a nuclear plant.

The World Health Organization endorses distribution of KI. Ireland, Sweden, France, and Switzerland not only stockpile KI, they pre-distribute it to the people of their nations.



Related:

  1. Disabled World (Jan 03, 2009). Iodine to be added to Bread in Australia
    https://www.disabled-world.com/news/research/iodine-bread.php
  2. University of Washington (Mar 30, 2011). Radioactivity from Japan Detected in Seattle
    https://www.disabled-world.com/disability/emergency/advisories/seattle-japan.php
  3. Thomas C. Weiss (Mar 24, 2009). Radiation Therapy for Treatment of Cancer Tumors
    https://www.disabled-world.com/health/cancer/treatment/radiation-therapy.php



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