RSC warns against scaremongering over the Japan crisis and global supplies of iodine

16 March 2011

Scientists at the Royal Society of Chemistry have warned against panic buying of potassium iodide tablets as the crisis in Japan continues.

Experts have also cautioned against scaremongering over the effects of the explosions at the Fukushima nuclear plant, saying that any comparisons with the 1986 Chernobyl disaster are unfounded.

Drug stores in the United States have reported a sudden surge in potassium iodide sales with many customers "panic-buying" due to developments in north-east Japan. One drug supplier says it has sold 250,000 anti-radiation pills to Americans concerned about possible exposure from Japanese nuclear reactors.

Dr Brian Carter, environmental sciences programme manager at the RSC, said there was no need for anyone in the United States to stock up on potassium iodide tablets: "It is highly unlikely that the situation in Japan will lead to a scenario where sufficient quantities of radioactive iodine, produced in a power station as a 3% fission product, are released into the atmosphere to cause a problem in the United States or anywhere else. For that to happen, huge quantities of iodine would need to be released into the atmosphere. The current situation is not of the same scale as the Chernobyl disaster.

"For the US to be affected, an explosion would have to occur that was powerful enough for radioactive iodine to reach the upper atmosphere, get picked up by the jet stream then carried to the United States - a similar situation that occurred with the ash from the volcanic eruption in Iceland last year. It is possible that some radioactive iodine could make it to the US via this route, but it is unlikely that it would be at the level requiring extensive dosing using potassium iodide tablets."

Dr Carter said that there was a plentiful global supply of iodine and that the people who do need the tablets are those in and around the exclusion zone in Japan. "Supply is incredibly unlikely to be an issue, provided that people are not driven into buying and using the pills by scaremongering."

Notes for editors

. Iodine (I) is an essential component of thyroid hormones. Iodine is absorbed by the human body into the bloodstream where it is taken up by the thyroid and incorporated into thyroid hormones. Exposure to a radioactive isotope of iodine, and subsequent concentration in the thyroid, can therefore result in damage to the thyroid. By ingesting potassium iodide (KI) tablets, a high dose of non-radioactive iodine saturates uptake mechanisms and counters the uptake of radioactive iodine into the thyroid. This competitive binding protects the thyroid from radiation damage by ensuring there is more non-radioactive iodine available for absorption than the radioactive form. It is important that potassium iodide is ingested before exposure to radioactive iodine for this protective effect to occur although ingestion afterwards will still have a mitigating effect.

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