(CNN) -- A radiation monitor in California has detected a trace of radioactive material from the stricken nuclear power plant in Japan, the Comprehensive Test Ban Treaty Organization said Friday. The exact amounts were not available, but the test ban organization's executive secretary, Tibor Toth, said the measurements were below what would be considered harmful to human health. The treaty organization's chief press officer, Annika Thunborg, said its officials were "absolutely certain" that the radiation detected in California is from Fukushima because the isotypes were consistent with those emitted by the Fukushima reactors, and the timing of their detection is consistent with projections.
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NEW: California exposure represents 1 millionth the background radiation dose rate
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Organization cites isotopes and timing for the conclusion
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EPA has found no increase in radiation levels
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A trace amount of radioactive material has been detected in Sacramento, California
Even before the discovery, some drugstores in @placeholder were running out of potassium iodide, which prevents some of radioactive iodine's harm to the thyroid.