Three students presented their findings for an Investigative Sociology class. Cilck here: FukushimaRadiationAffects (.pdf)
Three students presented their findings for an Investigative Sociology class. Cilck here: FukushimaRadiationAffects (.pdf)
MARCH 7, 2016
Five years after the Fukushima nuclear accident, there is still no U.S. federal agency responsible for studies of radioactive contaminants in the ocean. But scientific data about the levels of radioactivity in the ocean off our shores are available publicly thanks to ongoing efforts of independent researchers, including Ken Buesseler, a radiochemist with Woods Hole Oceanographic Institution (WHOI), who has led the effort to create and maintain an ocean monitoring network along the U.S. West Coast.
Since 2011, Buesseler has received contributions from citizens, small businesses, foundations and large companies to enable the sampling of nearly 1000 seawater samples for Fukushima radionuclides. Buesseler has been involved in seven cruises off Japan, sampling off Fukushima at least once every year, most recently in October 2015, and has published 19 peer-reviewed papers based on his analysis of seawater and sediments from the Pacific.
Buesseler’s work reveals that levels of radioactive forms of cesium in the ocean off Japan are thousands of times lower than during the peak releases in 2011, however, his analysis of cesium and strontium indicate releases from the plant are not yet “under control,” a statement that has been used by the Japanese government to describe the situation when levels are below regulatory limits.
“To date, we have focused our efforts on testing for the two isotopes of cesium (137 and 134) and strontium,” says Buesseler. “The cesium isotopes were the most abundant after the accident and provide the first indication of whether contamination from Fukushima is present in a seawater sample.” Because cesium-134 has a half-life of just two years, researchers know, when detected, that it comes from Fukushima. Cesium was 40 times more abundant in the water after the accident than strontium – a ratio that the scientists discover is changing.
The changing concentrations of both these elements in the waters off Japan tell a story of continued small leaks and raise concerns about the materials still stored at the reactor site.
Cesium levels in the water off Japan spiked after the accident, then fell dramatically in the following year. Since then, however, rather than a steady decline, the cesium levels have remained relatively constant.
“Levels today off Japan are thousands of times lower than during the peak releases in 2011,” says Buesseler. “But we are not seeing the steady decrease we would expect to see off Fukushima if all sources had stopped; rather, we are finding values are still elevated, which confirms that there is continued release from the plant.”
The highest level of cesium Buesseler’s team found in a sample taken off Japan in October 2015 measured 200 Becquerels per cubic meter (about 264 gallons) of seawater. (A Becquerel equals one decay event per second.) The samples were collected following a typhoon in September that delivered unusually heavy rains, which the researchers suspect may have caused elevated cesium levels in the ocean. These levels are still higher than prior to the accident but much lower than at the peak of the releases in 2011 when there were 50 million Bq/m3 in the ocean immediately off the dock at Fukushima.
While not declining as quickly as researchers had expected, the levels detected near Japan are still more than 40 times lower than US government safety limits for drinking water, and well below limits of concern for direct exposure while swimming, boating, or other recreational activities. At these lower levels, the concern remains for seafood safety and internal consumption of radioactive contaminants in fish.
The scientists have learned that cesium is just part of the story: Strontium, too, is not falling as expected. Strontium-90 has nearly the same half-life of cesium-137, and the researchers expected its levels would drop in step with cesium. Yet Buesseler and colleagues led by Universitat Autònoma of Barcelona, Spain have found that strontium is not decreasing as fast as cesium. Whereas there was approximately 40 times more cesium than strontium in the waters off Japan in 2011, by 2013, there was approximately 10 times more cesium than strontium. The concern lies in the thousands of tons of strontium still stored in tanks at the nuclear power plant and accumulated in buildings and soils, some of it still leaking into the ocean.
“We think that when there is heavy rain, more cesium, strontium, and other isotopes from the nuclear power plant are carried into the ocean,” says Buesseler. “We are still investigating how that occurs –whether carried in the groundwater or from the run off of sediment – but clearly it is highest near the contaminated site of the Fukushima nuclear power plants.”
Because strontium-90 mimics calcium in humans and animals, it is taken up by and concentrated in bones, where it remains for long periods of time, making it a greater health concern than cesium. Cesium, on the other hand, flushes out of the body much faster.
“Whereas it takes approximately two months for half of the radioactive cesium to flush out of fish, it takes more like two years for strontium to flush out of fish because it’s in their bones,” says Buesseler. “So if the supply of strontium to the ocean gets worse, it would take longer for the levels to decrease in seafood. So far, strontium levels are more than a hundred times lower than cesium when measured in fish, so it has not been a concern, but we have to monitor it.”
In addition to studying the waters off Japan, Buesseler and his colleagues have been actively monitoring the Pacific waters off the North American West Coast, primarily for cesium, the most abundant element after the accident. So far, they have detected only minute quantities of Fukushima cesium.
Fukushima-derived cesium first arrived along the west coast of North America in February 2015, measuring 6 Bq/m3 in Ucluelet, British Columbia. The highest numbers the researchers have seen in the eastern Pacific are almost 10 Bq/m3, found some 1,500 miles north of Hawaii.
“If you were to swim in waters at this level the health effects, or dose, would be 1000 times less than a single dental x-ray. This is not zero, but a very small risk that would not stop me from swimming or eating seafood from our side of the Pacific,” said Buesseler.
Because cesium levels have been so small and the cost of analyzing samples for strontium is so great, the researchers have not been analyzing samples off North America for strontium, until recently.
The researchers receive enough questions about strontium that they re-analyzed some of the West Coast samples that contained Fukushima cesium-134 looking for strontium, and have not detected any above the background levels that were there before Fukushima.
“So little strontium was released relative to cesium from Fukushima in 2011, that even though Fukushima cesium is detectable, the strontium-90 signal is not detectable in these samples, at least in the eastern Pacific,” says Buesseler.
The researchers continue to collect and analyze samples both from citizen scientists and, when possible, from ships and research cruises on the eastern side of the Pacific. The data are made publically available through the Our Radioactive Ocean, the crowd-funding website Buesseler created for this purpose. The site’s map interface allows the public to see where samples were collected and the cesium values measured in each sample.
Levels in the ocean are expected to peak along the West Coast of the U.S. some time in 2015 or 2016, so continued monitoring is needed.
The Woods Hole Oceanographic Institution is a private, non-profit organization on Cape Cod, Mass., dedicated to marine research, engineering, and higher education. Established in 1930 on a recommendation from the National Academy of Sciences, its primary mission is to understand the ocean and its interaction with the Earth as a whole, and to communicate a basic understanding of the ocean’s role in the changing global environment. For more information, please visit www.whoi.edu.MARCH 7, 2016 – See more at: http://www.whoi.edu/news-release/fukushima-site-still-leaking#sthash.VO5My4dq.dpuf
Join us February 13, 2016 for an evening of dancing and fun!
Includes a light dinner by Robert Tepper, Beer and Wine available
Valentine Theme Dessert Contest, bring your favorite treat and enter!
Raffle and silent auction
The Farm Band
The Best Witches Women’s Choir
The SoulShine Blues Band
Starr Hergenrather MC
Tickets are $25.00 available http://www.brownpapertickets.com/event/2462513
February 13, 2016
Sebastopol Community Cultural Center
390 Morris St, Sebastopol, CA 95472
6pm to 12am
Raffle tickets now on sale for a beautiful queen size ice-tie-dyed quilt, made by Linda Speel and quilted by Judy Meeker of More Than Warmth. Send checks to PRA, PO Box 255. Petaluma, CA 94953. Raffle tickets are $5 each or 5 for $20.00.
This is a flyer for a talk at Sonoma State University on Wednesday, November 18th at 7:00 p.m. featuring Arne Gunderson and Majia Nadesan.
Click on the image for a larger view.
Elizabeth Barger, PRA TN board member represented PeaceRoots recently at the Campaign Nonviolence National Conference in Santa Fe, New Mexico. See photo.
Trace amounts of radiation from the ruined Fukushima nuclear power plant in Japan were found in water samples collected in the Pacific Ocean 100 miles due west of Eureka, a Massachusetts-based researcher reported.
The concentration of cesium-134, a radioactive isotope known to come from the earthquake-and-tsunami ravaged Fukushima plant, was just barely detectable by his equipment and far below a level that would pose a risk to human health or marine life, said Ken Buesseler, a Woods Hole Oceanographic Institute marine chemist who has been monitoring North American coastal waters since January.
“We knew it was out there,” Buesseler said in a telephone interview Tuesday. “It’s good to be getting some numbers.”
Cesium in the sample collected in August offshore from Eureka was less than 2 becquerels per cubic meter, he said. The acceptable U.S. limit for cesium in drinking water is 7,400 becquerels.
“It wouldn’t stop me from swimming in it or from eating any local seafood,” Buesseler said.
Still, it is the first positive test for Fukushima radiation in water off the West Coast of the United States obtained by Buesseler’s crowd-funded, citizen-science program to collect and test water samples for cesium-134, the telltale marker for radiation from the Japanese power plant meltdown that followed the March 2011 earthquake and tsunami.
None of the more than 50 coastal seawater samples collected from Alaska to San Diego and on the north shore of Hawaii has shown any detectable amount of cesium-134, Buesseler said. But John Smith, a Canadian scientist, found levels of cesium similar to Buesseler’s sample on research cruises offshore from Canada earlier this year, according to a news release from the Woods Hole institution.
Scientific models have indicated a radioactive plume stretching 5,000 miles across the Pacific Ocean and expected to appear offshore of Alaska and the coast of Canada, move south along the coast of North America and eventually back toward Hawaii, the release said.
But the models “differ greatly on when and how much would be found,” it said.
The radioactive sample was collected in August by volunteers on the research vessel Point Sur sailing between Dutch Harbor, Alaska, and Eureka. Eureka is about 240 miles north of Bodega Bay.
Results of all samples taken and tested by Buesseler’s program are posted online at www.OurRadioactiveOcean.org.
The list includes a sample collected at Bodega Head on June 1 and three samples collected at Point Reyes in January, April and June. All four samples indicated a cesium-134 level “below detection,” or less than 0.2 becquerels per cubic meter.
A sample collected at the Farallon Islands in April had the same finding.
Dan Sythe, CEO of International Medcom, a Sebastopol company that makes radiation detection equipment, said he and Buesseler collected the seawater sample at Bodega Head.
Sythe, who plans to collect another sample on Nov. 22, said he’s been concerned since the Fukushima meltdown that radiation would reach the California coast. His company has conducted a small sampling program of seaweed and fish from Bodega Bay and tested it for radiation.
No radiation has been found here since the spring of 2011, Sythe said, but he shares Buesseler’s concern that the federal government is not monitoring West Coast waters. Some people are “on edge” about the prospect of Fukushima radiation reaching them, he said.
The radiation now reaching California is at the front edge of the plume, and Buesseler said the concentration is expected to increase, possibly to 10 becquerels, still a low level, over the next two to three years. But it’s worrisome, he said, that what’s happening now in Japan will reach North America in about three years.
News reports said that cesium contamination reached record levels — three times higher than previously recorded levels — after a typhoon swept through Japan last month. Buesseler said the ocean waters off Japan now contain equal concentrations of cesium and strontium-90, a dangerous isotope that lodges in bones and can cause cancer when ingested.
On shore at Fukushima, more than 1,000 storage tanks are holding water that was pumped out of the damaged reactor buildings with strontium-90 levels more than a hundred times greater than releases in 2011, Buesseler said.
“The red flag is we don’t know enough to predict this very well,” he said, referring to radiation’s slow movement across the Pacific Ocean.
You can reach Guy Kovner at 521-5457 or guy.kovner@ pressdemocrat.com. On Twitter @guykovner.
From The Press Democrat, Santa Rosa, CA, November 11, 2014
Please help fund more seawater tests at Bodega Head here: http://ourradioactiveocean.kintera.org/CS104
The “Level 8” Nuclear Disaster campaign is focused on mobilizing governments and organizations in every country to demand modification of the International Atomic Energy Agency’s current 7-level scale that indicates the severity of nuclear accidents. This newly proposed “Level 8” would firmly classify the gravity of the situation in Fukushima as a crisis calling for an unprecedented, internationally coordinated response of resources and aid in answer to a global nuclear emergency.