Radiation-tainted spinach from Japan's damaged nuclear reactors may sound scary, but here's a reality check: Even if any made it to stores there, you'd have to be Popeye to eat enough to worry.
With some fallout found in an increasing number of foods, Japan's government is taking steps to stop contaminated products from reaching consumers -- and the United States and other countries are double-checking imports.
The Food and Drug Administration said last week it will halt imports of dairy products and produce from the area of Japan where a nuclear reactor is leaking radiation. The FDA said those foods will be detained at entry and will not be sold to the public.
The Chernobyl disaster made clear that radiation from food can be a real risk: Thousands of cases of thyroid cancer after the 1986 reactor explosion there are blamed on the Soviet Union's failure to stop children in the region from drinking milk contaminated with radioactive iodine -- children who also weren't given a thyroid-protecting drug, potassium iodide.
Japan's earthquake-damaged reactors haven't leaked nearly as much radiation as Chernobyl, and aren't expected to -- and this time around, people are being warned, food is being tested and there's potassium iodide in the high-risk zone.
Japan has banned sale of milk, spinach and a few other products in regions from the leaking power plant toward Tokyo after discovery of higher-than-allowed levels of radiation in a range of foods. Last week, the World Health Organization said Japan should act quickly to ensure that no contaminated foods are sold -- as a precaution against long-term risk to nearby residents who otherwise might repeatedly consume large amounts of those products.
Still, international scientists say risk from food in Japan so far is low, especially outside the disaster zone -- and in the United States in particular because it imports very little food from Japan.
Here are questions and answers about the situation:
>Q: What's the danger?
A: Radioactive iodine, from food or the air, can build up in the thyroid, leading to thyroid cancer years later. Young children and pregnant women are at greatest risk. Thyroid cancer is one of the least fatal cancers if treated promptly.
Radioactive cesium can build up throughout the body, is harder to eliminate and high levels are thought to be a risk for various other cancers.
But it takes quite high exposure to harm, says Mettler: In contaminated villages around Chernobyl, thyroid cancer was documented. But if there was an increase in any other cancer, it was too small to detect, he says.
>Q: In what foods in Japan have these radioactive elements been found?
A: Iodine has been found mostly in milk and spinach, but also in chrysanthemum greens, leeks and a few other foods. Cesium also has been found in some vegetables. Levels found so far range from trace amounts to milk with iodine levels five times the acceptable limit, and in spinach, iodine levels 27 times the ceiling. Officials soon will test seafood.
>Q: If you ate that, what would it mean?
A: You'd have to eat 2 pounds of the most contaminated spinach to absorb about as much radiation as you'd get from a CT scan of the head, says Dr. Clifford Chao, radiologist-in-chief at New York-Presbyterian Hospital.
People who drank milk with the highest measured levels of iodine for two weeks would absorb less than a year's worth of natural background radiation, according to a report from British environmental radiation group, Mike Thorne and Associates Ltd. But infants would absorb more than adults.
>Q: What's being done to make sure contaminated foods don't reach consumers outside of Japan?
A: China, South Korea and a number of neighboring Asian countries have ordered radiation monitoring of food imports from Japan. Foods from Japan make up less than 4 percent of all U.S. imported foods.
>Q: How does radiation get into food anyway?
A: Fallout can land on crops in fields and wash into the soil to be soaked through the roots. Livestock can eat contaminated animal feed. It's possible seafood could be affected from contaminated water, although in the ocean "dilution would be huge," Mettler says.
Lauran Neergaard covers health and medical issues for the Associated Press. AP Medical Writer Margie Mason contributed to this report.