Experts in the U.S. say there is nothing to fear. They are monitoring the air quality here, but that isn't stopping people who want to buy emergency compounds, and some are inquiring about them.
It's hard for Kramers Health Foods store in Chicago's Loop to keep potassium-iodide on the shelves. Store employees say at least 30-40 people a day are either calling or coming in fearing nuclear radiation from Japan. The pills and liquid can be used to block the thyroid gland from absorbing radioactive iodide. No prescription is needed. Ordering more from suppliers hasn't been easy.
"We tried to get as much as we can, but some companies have it in stock, others don't have it in stock," said GD Jenkins, Kramers. "Right now, it's kind of hard to get."
Walgreen's doesn't carry the compound. But pharmacies across the country are reporting an increase in inquiries and sales of potassium iodide.
Jameela Maddox said she is worried about the risk of radiation from Japan and from local nuclear plants if anything ever happened here.
"Yes I am afraid, and I'm thinking about purchasing some potassium-iodide for just, precaution," Maddox said.
Others think the idea is preposterous.
"They should spend more time with their family, being nice to other people and less time panicking," said Christian Cole.
Northwestern University Professor Dr. William Small says people have a better chance of winning the lottery than needing the compound. Experts are assuring people that nuclear radiation from Japan won't reach the shores of America.
"Radiation is natural, so there's a natural background radiation everywhere. What we worry about is radiation going to a higher lever that has potential to cause harm. I think that risk is, if not zero, pretty darn close to zero," Small said.
"The real thing is how much radiation exposure would the people in the U.S. get, and that, I'm completely confident that it would be totally insignificant," said Dr. Elmer Lewis, Northwestern University nuclear engineer.
Lewis says people in the United States have nothing to fear from any significant radiation from Japan. Even under the worst-case scenario, such as a full-scale meltdown, radiation would dissipate long before it crosses the ocean.
"If the radiation that comes through and is less than you get from the normal chest X-ray or something, I don't think it's anything to be concerned about," said Lewis. "It may be detectable, but as far as health effects, I think in the U.S. it is not a worry."
Despite those assurances, the images of the Japanese nuclear disaster have some people in the U.S. worried. The Los Angeles Health Department issued a warning telling people not to take the tablets.
Typical radiation exposure increases when we fly, have X-rays done, and can even depend upon where we live. Chicagoans experienced 50 percent lower radiation levels than people in Denver, simply because of elevation.
ABC's Dan Harris recently used a Geiger counter to measure radiation spikes at several locations, including a monument in New York's Central Park.
"Granite is radioactive but perfectly safe," Harris said.;