NEW YORK -- Three weeks ago, it was a chemical compound familiar mostly to pharmacists and radiation experts. Now, in light of the ongoing nuclear crisis at the Fukushima Daiichi plant, potassium iodide has become a highly desired commodity in both Japan and the United States for its protection against radiation-induced thyroid cancer, especially in young children.
But in the years leading up to the calamity at Fukushima, the U.S. Nuclear Regulatory Commission and top officials in the Bush and Obama administrations have resisted efforts to expand distribution of potassium iodide to a wider array of people living near nuclear power plants in the United States.
Their principal argument has been that limiting access to food, water and milk potentially tainted by radioactive elements is more effective than supplying more radiation pills to the public.
Congress in 2002 passed a counterterrorism bill that required state and local governments to stock supplies of potassium iodide for people living within a 20-mile radius of nuclear power plants, an expansion of an optional 10-mile zone for the radiation pills that was previously in place. The law included a provision, however, that allowed the president to waive the new rules if alternative, more effective measures were identified.
In a January 2008 memo, a science adviser to President George W. Bush wrote that it would be more effective to tell people outside of the 10-mile zone to evacuate or avoid eating contaminated food from the area if there were a radiological release. The memo from John M. Marburger, the director of Bush's Office of Science and Technology Policy, wrote that the new 20-mile mandate "places an unnecessary burden on state and local emergency preparedness coordinators already struggling with the establishment and maintenance of programs within the 10-mile (emergency zone)."
He added, "A nuclear power plant accident that creates public health risks beyond the 10-mile range would be a highly unusual catastrophic event."
But as concerns widen over elevated radiation levels found in food and water supplies 50 to 100 miles away from the stricken Fukushima plant in Japan, there is a growing scrutiny of U.S. emergency response standards in the event of a nuclear disaster at home.
"When radiation comes out of a plant like this, you have no idea how far it's going to go, how heavily it's going impact one area versus another," said Jeffrey Patterson, a radiation exposure expert at the University of Wisconsin School of Medicine and Public Health who serves on the board of the advocacy group Physicians for Social Responsibility. "It has to do with wind patterns, it has to do with rainstorms. All of those things affect where the iodine goes."
The 10-mile emergency zone in the United States applies both to distribution of radiation pills and mandatory evacuation around a nuclear power plant, which is significantly less than the Obama administration's call last week for evacuation of U.S. citizens within 50 miles of the Fukushima Daiichi facility.
The disaster in Japan has prompted renewed calls to expand distribution of potassium iodide to a wider area, particularly from Rep. Edward Markey (D-Mass.), who authored the potassium iodide provision in the 2002 counterterrorism bill.
Markey wrote a letter to the Obama administration in the week after the tsunami urging that the 20-mile zone be adopted.
"We should not wait for a catastrophic accident at or a terrorist attack on a nuclear reactor in this country to occur to implement this common-sense emergency preparedness measure," Markey wrote. The letter followed a similar December 2009 letter to Obama. The administration rejected Markey's argument last summer, claiming that the previous limits were adequate.
Potassium iodide is in no way a cure for radiation emitted from a nuclear disaster, but if taken before or immediately after exposure it can be effective in reducing the risk of thyroid cancer. Taking the pills effectively fills the thyroid gland with enough iodine to prevent the gland from absorbing radioactive iodine, a harmful isotope emitted from a nuclear reactor. Infants and young children are particularly susceptible to thyroid injury.
The pills can also be harmful to young children, however, if taken in greater quantities than prescribed. Adults over 40 have the least risk of developing thyroid cancer from radiation, according to the Centers for Disease Control and Prevention, and also are more prone to an allergic reaction. The pills do not shield the body from other complications due to radioactive exposure, or from any other radioactive elements aside from iodine.
People who are allergic to iodine or have a preexisting thyroid disease are advised to consult doctors before taking potassium iodide, according to the CDC.
In recent weeks there has been a run on potassium iodide at drug stores in the United States, as some have panicked that radiation from the reactor in Japan would reach the West Coast. Local and state public health agencies in California have warned against taking potassium iodide in response to the Japanese reactor crisis, because of the minuscule chance of radiation traveling thousands of miles across the Pacific Ocean.
The debate in the United States involves those living in the immediate vicinity of a reactor.
The Nuclear Regulatory Commission and the Department of Health and Human Services have provided potassium iodide to state and local government agencies that request the pills within the 10-mile zones around nuclear plants. Local government agencies then either choose to distribute the potassium iodide or stockpile it in the event of an emergency.
At the time the 20-mile rules were proposed, the Nuclear Regulatory Commission wrote in formal comments that expanding potassium iodide distribution was "unnecessary."
"We have concluded that other, more effective, protective measures are in place to protect the thyroid gland in the event of a release of radioactive iodine," the commission wrote in a letter to the Department of Health and Human Services, which was tasked with enforcing the rule. The alternatives included preventing people in the area from eating or drinking contaminated food, milk and water, and protecting livestock.
Other state and local government bodies expressed concerns about requirements to expand stockpiles of potassium iodide. Although the NRC pays for the potassium iodide supplies, state and local governments must pay to administer the pills to the public.
A spokeswoman for the Nuclear Regulatory Commission wrote in an email, "As part of the NRC's 30-, 60- and 90-day report on 'lessons learned' from the Japanese nuclear emergency, all aspects of nuclear power plant safety and security regulations will be reviewed." A spokesman for Obama's Office of Science and Technology Policy offered a similar response, saying that distribution of potassium iodide will be among many policies under review.