A briefing for the California Coastal Commission ahead of its May 14 meeting concludes—yes, radiation from nuclear power plant meltdowns at Fukushima, Daiichi March 11, 2011, reached, and still arrives on the California coast, but no, don’t worry about it. The Japanese meltdowns that polluted air and water with radioactivity “reached the California coast within four-seven days of the accident, resulting in detectable levels of airborne radioactivity in California,” according to the staff report. It adds that an ocean plume carrying more isotopes “could possibly reach California within the next year.” The advisory tempers that information by noting that what’s reaching the coast is “expected to be only slightly above the pre-accident background” radiation levels. Background levels are not static. They constantly change based on what levels are in recent history. In some parts of the world, what’s considered background is much higher or lower than in other parts. While the Coastal Commission’s report notes that radioactivity from the nuclear meltdowns has been “massively diluted,” it adds that an ocean plume carrying more radioactivity is set to arrive at an unknown future date. And, even though the briefing minimizes exposure, it goes on to note that the U.S. Environmental Protection Agency’s RadNet program tests food products with “limited frequency” to establish any contamination.