TRENTON, Ontario
The first radioactivity from the Fukushima nuclear power plant disaster has been found in seawater collected along the shores of the west coast of Canada, scientists said Monday.
They said the level of radioactive waste in the British Columbia sample is low but the water, collected from a dock in Ucluelet on Vancouver Island, contained trace amounts of cesium-134 and cesium-137 -- isotopes that can come only from human sources.
The sample was collected in February -- four years after the power plant disaster -- but news of the radioactive finding was not announced until Monday by the Woods Hole Oceanographic Institution in Massachusetts.
The level poses no danger to humans, according to experts. If someone were to swim for six hours a day, 365 days of the year in water containing twice as much cesium as found in the sample, the radiation exposure would be 1,000 times less than from a single dental X-ray.
But it represents the first time radiation from Fukushima, where three nuclear reactors damaged by a tsunami in 2011 dumped radioactive water into the sea, has been discovered in samples taken along the Canadian, U.S. and Hawaiian coasts.
Scientists have collected water samples at 60 sites for the past 15 months, watching for radiation. Last November, radiation was found in a sample collected about 95 miles (150 kilometers) off the northern California shore but nothing was detected near the U.S. and Canadian coasts.
Volunteers have assisted scientists with the collection of water samples.
The Fukushima disaster is the largest ever accidental release of radioactive elements into the ocean and a marine chemist with the Massachusetts oceanic institution said in a statement that it was important to continue to monitor the water.
"We expect more of the sites will show detectable levels of cesium-134 in coming months, but ocean currents and exchange between offshore and coastal waters is quite complex," said Ken Buesseler. "Predicting the spread of radiation becomes more complex the closer it gets to the coast and we need the public’s help to continue this sampling network," he added.
