As we witness a nuclear tragedy unfold in Japan and people there receiving potassium iodide (KI), some ask about KI’s role in the United States.

What is KI? It is a salt, sometimes used as a table salt substitute. In some nuclear events, it can also protect thyroid glands, especially in children.

In certain nuclear disasters involving power plant reactors or bombs, radioactive iodine (radioiodine) can be released, then inhaled or ingested by people, and then absorbed in their thyroid glands. This can cause thyroid cancer, especially when fetuses and young children are exposed.

The 1986 Chernobyl nuclear power plant explosion in Ukraine caused thyroid cancer in an estimated 3,000 people within 10 years. Most were exposed to the radioiodine as children living within 200 miles of Chernobyl.

If KI is given by mouth just before or within a few hours of exposure, it is absorbed by the thyroid and prevents radioiodine from being absorbed.

There is no evidence that anyone in the United States will need KI for the current situation in Japan.

The Nuclear Regulatory Commission provides states with KI for those living within 10 miles of a nuclear power plant. KI is also available upon states’ requests in an emergency to the federal Strategic National Stockpile. Since Maine does not have a nuclear reactor, the only publicly available stockpiled KI is through a request to the SNS. It would then arrive several hours later by truck or air, perhaps too late.

Some advocate for a portion of the KI in the SNS to be pre-distributed to each state and major cities, while others say that is unnecessary.

Opponents point out that evacuation of people and interdiction of contaminated food supply are the most critical strategies. This is true. Evacuations (and very limited KI distribution) did not start in the Chernobyl area for 36 hours after the explosion, after exposure to radioiodine. Children were not protected against eating contaminated foods.

Opponents point out that U.S. nuclear power plants are built with better engineering, such as with secondary containment structures, making a Chernobyl explosion and wide dispersion of fallout less likely. This is true.

However, there are strong reasons for a more decentralized stockpile of KI.

• First, KI is inexpensive, long-lasting and safe. Only one or two doses are needed, and are available for a few pennies. Labels on KI note a seven-year shelf life, and with proper storage, can last many more. KI was administered safely to more than 17 million people in Poland after the Chernobyl explosion, and reported as effective at reducing thyroid cancer there.

• Second, evacuation and protection from the food supply are not always feasible. As in Japan, disasters are often coupled together, preventing ideal measures from being implemented.

• Third, while an earthquake and tsunami of the magnitude seen in Japan are unlikely here in New England, we are not completely immune. The largest recorded New England earthquake was estimated to be 6.3 (Richter Scale) and occurred in Cape Ann, Mass., in 1755, only miles from the current locations of two nuclear power plants (Seabrook and Pilgrim). There are three other nuclear power reactors in New England as well as one in nearby Point LePreau, New Brunswick. Five of these six are along the coast.

• Fourth, some European countries and states such as California take a multipronged approach to KI. The public is informed about steps to take during a nuclear event, including the possible use of KI. They offer pre-distribution of KI to families. They pre-position KI in evacuation centers and in locations within several miles of nuclear power plants in case evacuation is impossible.

Such decentralized distribution is needed for many antidotes with a narrow window for effectiveness. Maine’s own stockpile against arsenic helped save lives after a 2003 poisoning incident in northern Maine.

It is critical that people evacuate away from a nuclear disaster site and not consume contaminated foodstuff, but KI can be an important adjunct to ensure a nuclear disaster’s effects are as short-lived as possible, especially among our children.

The National Academy of Sciences and the American Thyroid Association recommend wider pre-distribution of KI to ensure its timely availability to all who may need it in a possible nuclear event.

As we approach the 25th anniversary of the Chernobyl tragedy and we witness another one unfolding in Japan, let us learn lessons from these disasters, and at the very least, incorporate KI into existing government emergency plans to especially protect our children.

– Special to The Press Herald