Seaborne radiation from the Fukushima nuclear disaster in Japan has for the first time been detected by researchers on the U.S. West Coast.

Fingerprint Of Fukushima

Researchers from the Woods Hole Oceanographic Institution reported that cesium-134, which has been labeled as the fingerprint of Fukushima, was detected and measured in samples of seawater taken from Tillamook Bay and Gold Beach in Oregon.

The Fukushima InFORM, a collaboration of scientific and non-profit organizations that include Woods Hole, has been monitoring the course of the radiation plume across the Pacific. The group has also detected for the first time cesium-134 in a Canadian salmon.

Danger Posed To Humans And The Environment

Although the detection of cesium-134 on U.S. shores may sound troubling, researchers said that the detected levels do not actually pose danger to humans and the environment.

Woods Hole Oceanographic Institution senior scientist Ken Buesseler said that the detected levels are very low and should not harm people who swim in the ocean or eat fish from the West Coast.

"To put it in context, if you were to swim every day for six hours a day in those waters for a year, that additional radiation from the addressed cesium from Japan ... is 1,000 times smaller than one dental X-ray," Buesseler said.

The seawater samples that were taken from Oregon, which were taken in January and February earlier this year, each had 0.3 becquerels per cubic meter of cesium-134.

Cesium-134 Also Detected In Fish From Canada

Last month, researchers involved in the InFORM project also reported that one sockeye salmon taken from Okanagan Lake in Canada tested positive for cesium-134.

Chemical oceanographer Jay Cullen, from the University of Victoria who leads InFORM efforts, said that this level was more than 1,000 times lower compared with the action level that was set by Health Canada and that this level poses no significant risk to consumers.

Fukushima Nuclear Disaster

The Fukushima Dai-ichi nuclear plant incident is the biggest nuclear disaster that occurred since the 1986 Chernobyl disaster. Following the 9.0 magnitude earthquake and tsunami that struck Japan in March 2011, three reactors melted down and contaminated water was released from the damaged nuclear plant.

Although there was no report of a fatality linked to the radiation, the eventual cancer deaths caused by the accident is estimated to be between 130 and 640. In 2015, 137 children who lived near the affected area were found to have thyroid cancer.