After the March 11 earthquake and tsunami that devastated parts of Japan and caused the largest nuclear accident since Chernobyl, concerns about radiation exposure emerged in North America.
From airborne radiation to contaminated seafood, fears persisted that the Japanese nuclear accident would have lasting consequences for Americans.
Many of these fears were unfounded though. Radiation from Japan was reportedly only detected at "trace" levels in the U.S. An EPA official reminded Americans that "it's important to understand how these low levels compare to the radiation we experience from natural sources every day," reported the Denver Post.
Within Japan, however, radiation is a much greater concern. A year after the disaster, a 12 mile exclusion zone still remains around the Fukushima plant, according to Discovery News. One of the radioactive isotopes emitted by the nuclear plant, cesium-137, has a half-life of 30 years, meaning it "is likely still in the environment."
To learn more about radiation exposure, click here for a visualization of radiation levels absorbed from common products and activities.
Look back in history and read about some of the most common, and ultimately probably overstated, radiation fears that hit North America in the year after the Fukushima disaster below:
In the weeks after the Fukushima disaster, some feared that radiation emitted from the stricken nuclear plant could reach the United States. At the end of March 2011, Nevada "joined several western states" that detected "extremely small amounts" of radioactive isotopes from Japan, according to the Associated Press. In April, "trace amounts" of radiation from Fukushima were detected in Denver drinking water, reported the Denver Post. Officials concluded that radiation levels were "harmless," however. An EPA spokesman said in a statement, "To put this drinking water sample into context, an infant would have to drink nearly 7,000 liters of this water to receive a radiation dose equal to just one day's worth of natural background exposure." Officials in Colorado also tested snowpack for traces of radiation.
Following the disaster, seafood vendors in California became concerned that radiation from Fukushima could affect fish sold in North America. With radioactive water from the nuclear plant entering the ocean, there was speculation that migratory tuna that spawned near Japan could become tainted before the U.S. West Coast. Timothy Mousseau, a professor of biological sciences at the University of South Carolina, told KABC, "There is a potential for genetic damage to these tunas for instance, as well as impacts on their reproductive abilities." Officials with the U.S. Food and Drug Administration were less concerned, however. AP reported that the FDA "played down the risks of seafood contamination," because of "dilution in the ocean." By December 2011, the FDA had not detected any "radionuclides" in fish imported from Japan, according to The Daily Beast. Officials in British Columbia also tested fish for elevated radiation levels. Flickr image courtesy of flickr4jazz.
HuffPost's Chris Kirkham reported that frantic sales of potassium iodide pills in the U.S. created "widespread paranoia" about radiation exposure. Although levels of radiation from Japan remained low in North America, potassium iodide distribution would not be uniform In the event of a disaster in the U.S. Stockpiling and distribution of the substance -- which can reduce the risk of thyroid cancer if taken "shortly before or after exposure to radiation" -- is left up to individual states. It was reported that only "Twenty-three of the 33 states that have people living within 10 miles of nuclear power plants have chosen to participate" in a federal emergency preparedness program that includes potassium iodide stockpiles.
In addition to seafood, concerns arose that other Japanese products could be contaminated. The FDA announced that imports of "all milk, fruit and vegetables from four Japanese prefectures" would be banned, reported HuffPost's William Alden.
Another concern involves the massive debris field that was washed out sea after the Japanese tsunami and is now making its way eastward across the Pacific. Although debris may reach the Hawaiian islands within the next month and the continental U.S. by early 2013, according to The Daily Beast, it is not expected to bring radiation problems with it. The American Nuclear Society concluded "that all off-site health consequences of the Fukushima Daiichi accident may ultimately be negligible." The EPA and FEMA both found that it would be "very highly unlikely" for debris to be radioactive, reported PBS.