Local produce, such as milk and spinach, are beginning to show potentially alarming signs of radiation up to 90 miles away from the damaged Fukushima nuclear power plants, according to Japanese officials. Will this be temporary or of long range concern?
According to an article in The New York Times:
TOKYO — The government said Saturday that it had found higher than normal levels of radioactive materials in spinach and milk at farms up to 90 miles away from the ravaged nuclear power plants, the first confirmation by officials that the unfolding nuclear crisis has affected the nation’s food supply.
An important note:
The newly discovered radioactivity contained in the average amount of spinach and milk consumed in an entire year would be equal to the amount received in a single CAT scan, he said.
“These levels do not pose an immediate threat to your health,” Mr. Edano said, adding that the Health, Labor and Welfare Ministry would provide additional details. “Please stay calm.”
Food safety inspectors said the amount of iodine-131 found in the tested milk was five times higher than levels deemed safe. They said the iodine found in the spinach was more than seven times higher. The spinach also contained slightly higher amounts of cesium-137.
Iodine-131 and cesium-137 are two of the more dangerous elements that are feared to have been released from the plants in Fukushima. Iodine-131 can be dangerous to human health, especially if absorbed through milk and milk products, because it can accumulate in the thyroid and cause cancer. Cesium-137 can damage cells and lead to an increased risk of cancer.
Those levels are well beyond what the Food and Drug Administration in the United States considers a cause for concern. But experts say Japan’s reassurances about food safety were probably accurate.
Dr. Swartz said people consuming milk and produce, particularly children and pregnant women, should be taking potassium iodide, which saturates the thyroid gland with nonradioactive iodine, and prevents it from taking in the radioactive form. Children and fetuses have the highest risk of thyroid cancer from exposure to radioactive iodine.
The Japanese authorities recommended Wednesday that people in the affected area start taking iodine.
According to the EPA:
What are the properties of cesium-137?
Cesium, as well as cesium-137, is a soft, malleable, silvery white metal. Cesium is one of only three metals that is a liquid near room temperature (83 °F). The half-life of cesium-137 is 30 years. It decays by emission of a beta particle and gamma rays to barium-137m.
What are the properties of iodine-129 and iodine-131?
Radioactive iodines have the same physical properties as stable iodine. However, radioactive iodines decay with time
Iodine is a nonmetallic, purplish-black crystalline solid. It has the unusual property of ‘sublimation,’ which means that it can go directly from a solid to a gas, without first becoming liquid. It sublimes to a deep violet vapor at room temperature. This vapor is irritating to the eyes, nose and throat. Iodine dissolves in alcohol and in water. It melts at 236 °F.
Iodine reacts easily with other chemicals, and isotopes of iodine are found as compounds rather than as a pure elemental nuclide. Thus, iodine-129 and -131 found in nuclear facilities and waste treatment plants quickly form compounds with the mixture of chemicals present. However, iodine released to the environment from nuclear power plants is usually a gas.
Iodine-129 has a half-life of 15.7 million years; iodine-131 has a half-life of about 8 days. Both emit beta particles upon radioactive decay.
Let us hope that this early detection of radiation levels in local produce will minimize risk to public health, and that levels will return to safe levels very soon.