For the first time since the nuclear power plant accident that crippled Japan's Fukushima Prefecture, trace amounts of radioactive elements leaking from the site have found their way to the waters off Vancouver, Canada.
Experts from the Woods Hole Oceanographic Institution (WHOI) discovered small amounts of radioactive materials in the seawater, believed to have originated from the Fukushima Daiichi Nuclear Power Plant meltdown in 2011. The water sample, which contained traces of cesium-134 and cesium-137 isotopes, was collected along the shores of Ucluelet, British Columbia on Feb. 19 through the help of staff from the Ucluelet Aquarium.
Since cesium-134 only has a two-year half-life, radioactive particles found in the Pacific Ocean would have been introduced only recently. This makes the Fukushima Daiichi site the most likely source.
WHOI marine chemist Ken Buesseler has been studying traces of radioactive materials found in seawater samples from the Pacific Ocean since 2011.
"Radioactivity can be dangerous, and we should be carefully monitoring the oceans after what is certainly the largest accidental release of radioactive contaminants to the oceans in history," Buesseler explained. "However, the levels we detected in Ucluelet are extremely low."
The WHOI has partnered with local volunteers to collect samples along the shores of the U.S., Hawaii, and Canadian West Coast. Over the past 15 months, the team has found minute radioactive elements that can be traced back to Fukushima. This occurrence has long been predicted by scientists through the use of computer models.
In November 2014, the WHOI collected the first water sample with traceable levels of radioactivity from Fukushima. The sample was recovered 100 miles off the shore of Northern California.
To establish more monitoring stations along the coast of British Columbia, Buesseler and his group joined forces with the Integrated Fukushima Ocean Radionuclide Monitoring (InFORM) Network, a Canadian-funded program headed by Jay Cullen from the University of Victoria.
The nuclear disaster that Japan experienced in March 2011 was caused by a massive earthquake and tsunami. The incident raised concerns over the possible dangers of the radioactive fallout from Japan spreading in the Pacific Ocean.
"The levels we are seeing are so low that we don't expect there to be impacts on the health of either the marine environment or people living along the coast," Cullen said.
The water sample found in Ucluelet had 1.4 Becquerels per cubic meter (the number of decay events per second per 260 gallons of water) of cesium-134. The team believes that this result, along with the 5.8 Becquerels per cubic meter of cesium-137 traced, is clear evidence that the radioactive materials originated from Fukushima.
Despite this, scientists say that these trace amounts are well below the internationally defined radioactive levels dangerous to humans and marine life.
Peer van de Rijk, head of the World Information Service on Energy (WISE), challenged this theory, arguing that the radioactive particles in the water, regardless of the amount, are still a serious danger.
"There is only one safe level: that is zero level. Every amount is possibly harmful, and it adds up," de Rijk said. "You can never say that there is a safe dose for radiation."
Discussing the effects of cesium-134 and cesium-137, de Rijk explained that if these particles accumulate in the body, they can be harmful to the structure of cells.
