A team of scientists released new data Wednesday indicating that evidence of radiation from the 2011 Fukushima nuclear disaster has not yet reached the U.S. west coast shoreline.
Kelp Watch 2014, a collaborative effort, has been using kelp to detect and measure the radioactivity in seawater from the Fukushima Daiichi disaster, in which dangerous levels of radiation were leaked from a Japanese nuclear facility. The team is led by Steven Manley, a professor of marine biology at Cal State Long Beach, and Kai Vetter, a professor of nuclear physics and engineering at UC Berkeley.
After the disaster, radioactive materials began leaking into the surrounding waters, and many were concerned about the radiation reaching the west coast of the United States.
“We wanted to contribute to the discussion and address public concerns by providing data and facts,” Vetter said.
After analyzing kelp samples collected between February and March in 26 locations along the Pacific coast, including samples taken in Hawaii and Guam, the team concluded that there were no signs that radiation from the nuclear power plant disaster has spread to the west coast shoreline.
According to Vetter, kelp, which absorbs nutrients from the sea water and is highly sensitive to small concentrations of radiation, is also a very cost-efficient way to test for radioactivity, as it can be commonly found on the ocean surface.
Manley and more than 40 other marine scientists and educators were responsible for collecting and harvesting the kelp. The team collected about 14 pounds of kelp from each sampling location, which were then shipped to three processing centers on the West Coast, one of which was Manley’s lab. There, he says, the kelp blades were dried in an oven and ground into particles. The kelp powder was then sent to Lawrence Berkeley National Laboratory, where Vetter serves as director of applied nuclear physics, for analysis of radioactive isotopes in the composition.
Vetter said the team looked for traces of the radioactive isotope cesium 134, a main contaminant released from the disaster, but did not detect it in the kelp samples. Although the team observed small traces of other radioactive isotopes in the kelp, Vetter said he attributes this to naturally occurring radiation and prior events — not Fukushima.
“The models that predicted the arrival of radioactive seawater stated that the seawater could come anytime from late March or early April to the end of year, so we didn’t really expect to see it around this time,” Manley said. “The data we gathered will help provide a good baseline to compare future samples to.”
Manley said the team plans to collect and release two other sets of data samples of kelp in 2014, with the next one scheduled for around July.
“According to predictions based on our scientific models, we should see at some point the arrival of small concentrations of cesium,” Vetter said. “But the concentration we are expecting is extremely small and most likely won’t be a danger to the public.”