Tests of water samples off the U.S. West Coast have found no indications of radiation from Japan's 2011 Fukushima nuclear disaster, even though low levels of radiation are expected to reach the shoreline sometime in the future, scientists said earlier this week.
The results were processed from water gathered by the Oregon conservation group, which were transferred to East Coast scientists to be tested afterwards. The results were as expected -- no indications of radiation from Fukushima. Five more tests are planned in six month intervals to see if any radiation will be detected in the future.
"We've seen radiation halfway across the Pacific, north of Hawaii, but in U.S. waters there has been none, yet," Woods Hole Oceanographic Institution senior scientist Ken Buesseler said.
Tests of some fish species, which can race across the ocean more quickly than slow-moving currents, have shown higher levels of radiation, although radiation levels in sea life off the U.S. shore are still safe, Buesseler said.
York Johnson, water quality coordinator with Oregon conservation group Tillamook Estuaries Partnership, which collected the water samples, said scientific models of ocean currents suggest that cesium 134 isotopes from Fukushima could reach Oregon's shores later this year in low levels.
Johnson's group headlines a set of crowd funded study organizations for the study of ocean radiation over the next several months after the federal government decided it was not a big enough threat factor to track the spread of the radiation across the Pacific Ocean.
"We wanted to be able to talk to the community about what we are seeing – and to have evidence," Johnson said, adding that the coast should still be safe for recreation even if radiation levels climb over the next several years as expected.
Tests off the coast of Japan shortly after the 2011 earthquake and nuclear plant disaster measured radiation at 50 million becquerel per cubic meter, Buesseler said. A "becquerel" is a unit of radioactivity.
"When it is at 50 million, you have direct effects on mortality, reproductive effects. That is a seriously high number," Buesseler said. "The U.S. Environmental Protection Agency allows us to drink water up to about 7,400."
Researchers say the radioactive plume from Japan has dispersed over the last three years and when it does reach North American shores, it will most likely be so diluted that it won't pose a threat to humans.