Scientists have crowdsourced a network of volunteers taking water samples at beaches along the West Coast in hopes of capturing a detailed look at low levels of radiation drifting across the ocean since the 2011 tsunami that devastated a nuclear power plant in Japan.
With the risk to public health extremely low, the effort is more about perfecting computer models that will better predict the behavior of chemical and radiation spills in the future than bracing for a threat, researchers say.
Federal agencies are not sampling at the beach. Washington also doesn’t test ocean water for radiation, Washington Department of Health spokesman Donn Moyer said. The state of Oregon is sampling but looking for higher radiation levels closer to federal health standards, state health physicist Daryl Leon said.
The March 2011 tsunami off Japan flooded the Fukushima Dai-ichi nuclear plant, causing radiation-contaminated water to spill into the Pacific. Airborne radiation was detected in milk and rainwater in the U.S. soon afterward. But things move much more slowly in the ocean.
“We know there’s contaminated water coming out of there, even today,” Ken Buesseler, a senior scientist at the Woods Hole Oceanographic Institution in Massachusetts, said in a video appealing for volunteers and contributions.
“What we don’t really know is how fast and how much is being transported across the Pacific,” he added. “Yes, the models tell us it will be safe. Yes, the levels we expect off the coast of the U.S. and Canada are expected to be low. But we need measurements, especially now as the plume begins to arrive along the West Coast.”
Buesseler said he hopes the sampling will go on every two or three months for the next two to three years.
Two different models have been published in peer-reviewed scientific journals predicting the spread of radioactive isotopes of cesium and iodine from Fukushima. One, known as Rossi et al., shows the leading edge of the plume hitting the West Coast from southeast Alaska to Southern California by April. The other, known as Behrens et al., shows the plume hitting Southeast Alaska, British Columbia and Washington by March 2016.
The isotopes have been detected at very low levels at a Canadian sampling point far out to sea earlier than the models predicted, but not yet reported at the beach, said Kathryn Higley, head of the Department of Nuclear Engineering and Radiation Health Physics at Oregon State University. The Rossi model predicts levels a little higher than the fallout from nuclear weapons testing in the 1960s. The Behrens model predicts lower levels like those seen in the ocean in the 1990s, after the radiation had decayed and dissipated.