Traces Of Fukushima Radioactivity Detected In West Coast Waters

By Tom Banse, Northwest News Network

An oceanography institute announced today (Monday) that trace amounts of radioactivity from Fukushima have been detected off the West Coast. This stems from the 2011 nuclear plant accident in Japan.

Radiation experts say the very low levels of radioactivity measured do not pose a health threat here.

The post-earthquake and tsunami nuke plant accident spilled a large amount of radioactive contamination into the Pacific three years ago. Oceanographers projected that it would take until this year for highly diluted traces to reach the West Coast of North America. And a recent research cruise from Dutch Harbor, Alaska to Eureka, California detected the front edge of the plume multiple times between 100 and 1,000 miles offshore. Ken Buesseler is a senior scientist at the Woods Hole Oceanographic Institution.

“The levels offshore still are quite low. So by that I mean they are a couple units of these Becquerels per cubic meter, something that is about a thousand times less than a drinking water standard,” he said.

Buesseler said he is reluctant to “trivialize” any amount of radiation, but says he personally has no concerns about swimming, boating or eating fish from local waters.

Since the start of this year, Buesseler’s lab has also tested about 50 seawater samples collected at the shore by concerned coastal residents from California to Alaska. All of those results have come up negative. This sampling was paid for through crowdfunding as part of an ongoing “citizen science” monitoring project initiated by Buesseler.

A parallel but independent monitoring effort run through the radiation health lab at Oregon State University found no detectable traces of Fukushima radiation in seawater samples collected earlier this year in near shore waters along the Pacific Northwest coast.

Scientists tracking the plume from Japan look for a short-lived cesium isotope, cesium-134, that serves as the “fingerprint” of Fukushima contamination.

For context, radioecologist Delvan Neville at OSU said it helps to know that the cesium-134 levels reported by the Woods Hole researcher are “much less than the natural background radiation in seawater.” In an interview, Neville was certain the low levels of Fukushima-derived isotopes detected in the northeastern Pacific do not pose an environmental or human health radiological threat.

Buesseler is scheduled to present his findings Thursday during the annual meeting of the Society of Environmental Toxicology and Chemistry in Vancouver, Canada.

He is also responding to questions from the public on the “Ask Me Anything” forum on Reddit at 10 a.m. PST Monday.

The results Buesseler reported corroborate detections of cesium-134 in seawater far offshore from Vancouver Island starting last year. Scientists from Fisheries and Oceans Canada, Health Canada and the University of Victoria are collaborating on a monitoring effort that also includes fish sampling.

None of the salmon, halibut, sablefish and spiny dogfish they have analyzed have contained detectable levels of radiation traceable to Fukushima.

This was first reported for the Northwest News Network.

 

Study Finds No Evidence Of ‘Ocean-Borne’ Fukushima Radiation Along West Coast

 

A graduate student in the marine biology program at Cal State Long Beach collects kelp in the waters off of Long Beach during Kelp Watch 2014’s initial collection of samples. (Photo credit: David J. Nelson/Cal State Long Beach)

A graduate student in the marine biology program at Cal State Long Beach collects kelp in the waters off of Long Beach during Kelp Watch 2014’s initial collection of samples. (Photo credit: David J. Nelson/Cal State Long Beach)

May 7, 2014

Tom Reopelle CBS Los Angeles

LONG BEACH (CBSLA.com) — The West Coast shoreline shows no signs of ocean-borne radiation from Japan’s Fukushima nuclear power plant disaster, scientists said Wednesday.

KNX 1070′s Tom Reopelle reports researchers from CSU Long Beach and other schools are sampling kelp along the California coastline to determine whether seawater arriving from Japan poses any public health threat.

The Kelp Watch 2014 project – which is co-headed by Dr. Steven Manley, marine biology professor at Long Beach State – has gathered kelp samples from as far north as Kodiak Island, Alaska, to as far south as Baja California to determine the extent of possible radiation contamination from the Fukushima disaster in March 2011.

During the first phase of the project, samples were primarily collected from Feb. 24 through March 14 at 38 of the 44 sites originally identified by researchers for testing of cesium-137 and -134 isotopes, according to researchers.

“So far, it appears that, based on our analysis of kelp, that none of the Fukushima radiation has arrived via the ocean current to our shoreline,” Manley said.

Two sites in the tropics – Hawaii and Guam, where non-kelp brown algae were sampled — were also negative for Fukushima radiation, according to researchers.

Manley noted that the project also has giant kelp from off the coast of Chile in South America that serves as a reference site, far removed from any potential influence from Fukushima.

The study somewhat contradicted earlier findings from a 2012 Long Beach State study that found low levels of radioactive isotopes in seaweed found along the southern Pacific Coast.

While the project’s participants are primarily from academia who have agreed to work pro bono, donors with the USC-Sea Grant and California State University Council on Ocean Affairs, Science & Technology (COAST) have agreed to contribute funds to the project, researchers said.

The second of the three 2014 sampling periods is scheduled to begin in early July.

Researchers Detect Fukushima Radiation in Albacore Tuna Caught off Oregon Coast

Researchers check albacore tuna caught off Oregon Coast radiation from Fukushima, Japan. | credit: Oregon State University | rollover image for more

Researchers check albacore tuna caught off Oregon Coast radiation from Fukushima, Japan. | credit: Oregon State University

By Angela Kellner, KLCC

Researchers at Oregon State University have found trace levels of radiation from Fukushima in albacore tuna caught off the Oregon coast. Results of the study are being published in the journal Environmental Science and Technology.

The Fukushima Daiichi nuclear power plant was destroyed by the earthquake that hit Japan in 2011. Radiation has made its way into the Pacific Ocean, raising concerns about exposure to Cesium-134 and 137.

Two OSU researchers, Jason Phillips and Delvan Neville, looked specifically at albacore tuna. The large fish migrate far distances and are near the top of the aquatic food chain. The study found detectable levels of Fukushima radiation in the 4-year-old fish. The majority of age 3 fish had no detectable level of Cesium-134. Neville said the amount found is very small compared to the radiation people are exposed to everyday.

“A year of albacore, which for the average American is about 16 pounds, at the highest concentration we saw is the same dose you’d get by spending 23-seconds in a stuffy basement,” Neville said.

Other authors of the study were Richard Brodeur of NOAA’s Northwest Fisheries Science Center, and Kathryn Higley of the OSU Department of Nuclear Engineering and Radiation Health Physics. The study was supported by OSU and NOAA, with continued support from the Oregon Sea Grant.

Neville said the next round of research will study a larger number of albacore. For his dissertation, Neville will examine the near-surface food web along the coasts of Washington, Oregon and Northern California.

Something is killing starfish; scientists race to find out what

Seastar wasting syndromeA diseased seastar. (Nate Fletcher / Pacific Rocky Intertidal Monitoring Lab)

Seastar wasting syndrome
A diseased seastar. (Nate Fletcher / Pacific Rocky Intertidal Monitoring Lab)

 

Up and down the West Coast, starfish are dying.

By Deborah Netburn

February 4, 2014 LATimes

Casualties of a mysterious disease known as seastar wasting syndrome, they are dying in Alaska, deteriorating in San Diego and disappearing from long stretches in between.

Death from the disease is quick and icky. It begins with a small lesion on a starfish’s body that rapidly develops into an infection the animal cannot fight.

Over the course of the disease the starfish’s legs might drop off, or even separate from the body and start to crawl away, as you can see in the PBS news story below.

Pete Raimondi, a professor at UC Santa Cruz who has been tracking the seastar crisis, said a starfish’s leg moving away from its central disk is akin to a lizard’s tail continuing to wriggle even after it has snapped off the lizard’s body.

“Starfish don’t have a central nervous system, so it’s not like if you chopped off your arm,” he said. “The arms can still be mobile and operate on their own for a period of time – longer than you think.”

The seastar wasting epidemic was first observed last summer. Some wondered whether radiation that leaked into the Pacific Ocean from the Fukushima nuclear plant in Japan might be the cause.

“I think it is almost entirely impossible to be related to Fukushima,” Raimondi told the Los Angeles Times. “We haven’t ruled it out, but there are so many more likely things going on. And there is no evidence that radiation has gotten to California.”

A more likely culprit is a pathogen. Either a virus, parasite or bacteria infects the animal and compromises the immune system, which leads to a secondary bacterial infection that ultimately kills the animal.

Raimondi said it shouldn’t be long before scientists isolated the responsible pathogen. “We should know pretty soon,” he said.

Fishermen test their own salmon for Fukushima radiation

File photo of Pete Knutson of Loki Fish by Greg Gilbert/The Seattle Times

File photo of Pete Knutson of Loki Fish by Greg Gilbert/The Seattle Times

Posted by Rebekah Denn, The Seattle Times

Is it safe to eat fish from the Pacific Ocean in the wake of the Fukushima nuclear disaster? The consensus since the 2011 power plant failure has been a yes, but Seattle’s Loki Fish Co. found customers remained concerned.

The fishing company, a local institution, went on to do its own testing for radiation levels in its fish, and shared the laboratory reports online. (The short version: The fish were fine.)

“We were getting so much blowback from customers that have just been reading incredibly paranoid stuff on the Internet,” said Pete Knutson, co-founder of the family-owned business. Beyond some of the “off the charts” fears, though, he understands why people would be concerned, and he’s always interested in knowing how pure his own products are. The decision: “Let’s just do the testing and let the chips fall where they may.”

It helped his decision that he could find no specifics from public agencies like the FDA, which simply says on its website that “to date, FDA has no evidence that radionuclides from the Fukushima incident are present in the U.S. food supply at levels that would pose a public health concern.”

After the $1,200 endeavor, Loki’s web page reported that “All seven stocks of salmon were tested for the radionuclides associated with the nuclear plant failures in Japan: Cesium 134, Cesium 137, and Iodine 131. Of the seven samples, five did not register detectable levels of radionuclides. Two of the samples registered at trace levels – Alaskan Keta at 1.4Bq/kg for Cesium 137, and Alaskan Pink at 1.2Bq/kg for Cesium 134. There were no detectable levels of iodine-131 in any samples.

“To put those numbers in perspective, the critical limit set by the FDA for either Cesium-134 or Cesium-137 is 370 Bq/kg, far above the amount found in Loki’s Alaskan Keta and Pink salmon.”

The full lab testing reports can also be downloaded from the page. (There was also a certain amount of both natural and man-made radioactivity in the ocean pre-Fukushima.)

Is that enough to ease the minds of diners? One customer on the Loki Facebook page wrote “A. it’s only January. B. keep testing.” Another warned that “it would be unrealistic to tell people afraid of the radiation on the basis of one test that the fish is safe forever.”

Knutson said that “I tell people, this isn’t conclusive, it’s only 7 samples, but it’s a random sampling,” not one that could have been gamed in any way. At the least, “it makes me feel better.”

Bellingham-based Vital Choice Wild Seafood & Organics, which sells fish online, has had fish tested several times with similar results. Knutson wasn’t aware of anyone else doing so, but thinks such moves might be more common in the future. His son, Dylan, faced regular queries about the radiation issue at Loki’s farmers market tables, though those customers are “a pretty motivated group that’s interested in chain of custody,” and perhaps more likely to raise the issue.

People are “not fully confident the government’s telling the truth,” or that corporations are telling the truth, he said. Sharing such direct data from producer to customer, he said, might just be “where the future of food is.”

Updated Jan. 20 to reflect additional Vital Choice tests.

Scientists Say Stop Worrying About Fukushima Radioactivity In Fish

Pete Knutson and his son, Dylan, sell their wild-caught salmon at farmer's markets around Seattle. "We had people passing on our fish this year. It was directly because they were worried about Fukushima." | credit: Ashley Ahearn

Pete Knutson and his son, Dylan, sell their wild-caught salmon at farmer’s markets around Seattle. “We had people passing on our fish this year. It was directly because they were worried about Fukushima.” | credit: Ashley Ahearn

Ashley Ahearn, OPB

SEATTLE — Japan’s nuclear disaster released hundreds of millions of gallons of radioactive water in 2011, sparking rampant speculation that a contaminated plume would reach the waters of North America’s West Coast.

Three years later, such speculation is alive and well on the Internet. Consider this video shot at a beach in Northern California and posted last month to YouTube:

 

 

“This is one of the problems,” says Kim Martini, a physical oceanographer at the University of Washington who has been following the issue closely. A Geiger counter can tell you if there’s radiation present, she said, “but it can’t differentiate between different kinds of radiation.”

California state officials went back and tested the beach and found the radiation to be naturally occurring in the rock formations there.

Martini and other scientists have received hate mail for trying to dispel some of the online fears about radioactive pollution resulting from the meltdown of Japan’s Fukushima Daichi Nuclear Power Station. It was triggered by the Tohoku earthquake and tsunami, which struck Japan in March, 2011.

“There’s definitely people that you’re never going to convince… I don’t know what to tell you. The science says it’s OK,” Martini said.

Scientists in California and Oregon have collected samples of tuna, a fish known to migrate back and forth across the Pacific, and analyzed them for radioactive isotopes, Cesium-134 in particular, from Fukushima.

Delvan Neville, a PhD candidate in Radiation Health Physics at Oregon State University, has tested dozens of samples of albacore tuna for radioactivity. The U.S. Food and Drug Administration’s intervention levels for cesium 134 and cesium 137 is 1200 becquerels per kilogram. The highest levels he’s seen in his albacore, of both cesium 134 and cesium 137 combined, is 1 becquerel per kilogram – a level so low that his device couldn’t pick it up until he concentrated the samples.

“That’s more than 1,000 times lower than the point where the FDA would even think about whether they need to let people eat that food still,” he said.

Neville joked that he was eating the tuna he caught right alongside the samples he collected for science, “which was actually kind of fun because then I was telling people as we were eating at the table what their approximate dose was due to Fukushima from the food they were eating and it’s this ridiculously small number.”

There is radioactive material from Fukushima making its way across the Pacific Ocean and it has already reached the West Coast in small amounts. The largest concentration of radioactive water released during the nuclear meltdown is moving in a plume across the middle of the Pacific, but models project that the majority of the radioactive water will sink or be pushed west again before it hits the U.S. Scientists are still debating how high those radioactivity levels could be. Here’s an interesting video on ocean currents and Fukushima radioactivity:

Kim Martini says here on the West Coast, scientists have found very low levels of cesium from Fukushima:

“It’s about 20,000 times less than drinking water standards. And so what we like to say is it’s detectable but harmless.”

But despite all the evidence, some fish consumers on the West Coast have been wary.

Pete Knutson has been fishing for salmon in Alaska for more than 40 years. He owns and operates Loki Fish Company with his two sons. On the weekends you’ll find him selling his fish at farmer’s markets around Seattle, with white hair flowing out from under a knit cap and an easy laugh that draws passersby up to his stall.

“We have all different kinds of salmon products, pickled salmon, ikura, smoked salmon, canned salmon, whole pink salmon over there,” he gestures to rows of neatly packaged pink salmon meat.

Knutson’s in the business of catching fish, not testing them. But after the Fukushima meltdown his customers wanted answers about the safety of his product.

So he sent seven salmon samples off to an internationally certified lab to test for radioactive isotopes. Five of the seven samples came back without any detectable levels of radioactive isotopes from Fukushima, Knutson said, and two showed levels several hundred times below approved levels.

“We feel very good about the results,” he said.

The tests cost Knutson $1,200 but he says it was a necessary investment.

“People do not trust governmental authorities. They don’t trust corporations. They don’t trust explanations and they don’t have a good science background,” Knutson said. “So it makes for a good combination where rumors can start spreading like wildfire, rumors like the whole pacific is poisoned, rumors like starfish, salmon seals, they’re all poisoned from the radiation and it’s not true. This is not definitive proof that there’s not a problem but it’s an indicator.”

Fisheries in Japan remain closed because of high levels of radioactivity and the ongoing release of contaminated groundwater from the nuclear site, but the FDA, Washington Department of Health, Woods Hole Oceanographic Institute and others have stressed that levels of radioactivity in fish that have made their way across the Pacific are not at levels of concern.

Fukushima Nuclear Plant Reports Another Radioactive Water Leak

 

By MARI YAMAGUCHI

Oct 3, 2013

TOKYO — TOKYO (AP) — Another day, another radioactive-water spill. The operator of the meltdown-plagued Fukushima Dai-ichi nuclear plant says at least 430 liters (110 gallons) spilled when workers overfilled a storage tank that lacked a gauge that could have warned them of the danger.

The amount is tiny compared to the untold thousands of tons of radioactive water that have leaked, much of it into the Pacific Ocean, since a massive earthquake and tsunami wrecked the plant in 2011. But the error is one of many the operator has committed as it struggles to manage a seemingly endless, tainted flow.

Plant operator Tokyo Electric Power Co. said Thursday workers detected the water spilling from the top of one large tank when they were patrolling the site the night before. The tank is one of about 1,000 erected on the grounds around the plant to hold water used to cool the melted nuclear fuel in the broken reactors.

TEPCO said the water spilled out of a concrete barrier surrounding the tank and believed that most of it reached the sea via a ditch next to the river.

The new leak is sure to add to public concern and criticism of TEPCO and the government for their handling of the nuclear crisis. In August, the utility reported a 300-ton leak from another storage tank, one of a string of leaks in recent months.

That came after the utility acknowledged that contaminated groundwater was seeping into ocean at a rate of 300 tons a day.

TEPCO spokesman Masayuki Ono told an urgent news conference Thursday that the overflow occurred at a tank without a water gauge and standing on an unlevel ground, slightly tilting toward the sea. The tank was already nearly full, but workers pumped in more contaminated water into it to maximize capacity as the plant was facing storage crunch.

Experts have faulted TEPCO for sloppiness in its handling of the water management, including insufficient tank inspection records, lack of water gauges, as well as connecting hoses lying directly on the grass-covered ground. Until recently, only one worker was assigned to 500 tanks in a two-hour patrol.

In recent meetings, regulators criticized TEPCO for even lacking basic skills to properly measure radioactivity in contaminated areas, and taking too long to find causes in case of problems. They also have criticized the one-foot (30-centimeter) high protective barriers around the tanks as being too low.

The government has said it will spend $470 billion to build an underground “ice wall” around the reactor and turbine buildings to block groundwater inflows and prevent potential leaks from spreading. It is also funding more advanced water treatment equipment to make the contaminated water clean enough to be eventually released into the sea.

 

 

 

Fukushima crisis new blow to fishermen’s hopes

In this Aug. 26, 2013 photo, fisherman Fumio Suzuki watches the sunrise aboard his boat Ebisu Maru before the star of fishing in the waters off Iwaki, about 40 kilometers (25 miles) south of the tsunami-crippled Fukushima Dai-ichi nuclear power plant, Japan. Suzuki's trawler is one of 14 at his port helping to conduct once-a-week fishing expeditions in rotation to measure radiation levels of fish they catch in the waters off Fukushima. Fishermen in the area hope to resume test catches following favorable sampling results more than two years after the disaster, though for now fishing is suspended due to leaks of radiation-contaminated water from storage tanks at the nuclear power plant. Photo: Koji Ueda

In this Aug. 26, 2013 photo, fisherman Fumio Suzuki watches the sunrise aboard his boat Ebisu Maru before the star of fishing in the waters off Iwaki, about 40 kilometers (25 miles) south of the tsunami-crippled Fukushima Dai-ichi nuclear power plant, Japan. Suzuki’s trawler is one of 14 at his port helping to conduct once-a-week fishing expeditions in rotation to measure radiation levels of fish they catch in the waters off Fukushima. Fishermen in the area hope to resume test catches following favorable sampling results more than two years after the disaster, though for now fishing is suspended due to leaks of radiation-contaminated water from storage tanks at the nuclear power plant. Photo: Koji Ueda

By MIKI TODA and KOJI UEDA, Associated Press

YOTSUKURA, Japan (AP) — Third-generation fisherman Fumio Suzuki sets out into the Pacific Ocean every seven weeks. Not to catch fish to sell, but to catch fish that can be tested for radiation.

For the last 2 ½ years, fishermen from the port of Yotsukura near the stricken Fukushima Dai-Ichi nuclear plant have been mostly stuck on land with little to do. There is no commercial fishing along most of the Fukushima coast. In a nation highly sensitive to food safety, there is no market for the fish caught near the stricken plant because the meltdowns it suffered contaminated the ocean water and marine life with radiation.

A sliver of hope emerged after recent sampling results showed a decline in radioactivity in some fish species. But a new crisis spawned by fresh leaks of radioactive water from the Fukushima plant last week may have dashed those prospects.

Fishermen like 47-year-old Suzuki now wonder whether they ever will be able to resume fishing, a mainstay for many small rural communities like Yotsukura, 45 kilometers (30 miles) south of the Fukushima plant. His son has already moved on, looking for work in construction.

“The operators (of the plant) are reacting too late every time in whatever they do,” said Suzuki, who works with his 79-year-old father Choji after inheriting the family business from him.

“We say, ‘Don’t spill contaminated water,’ and they spilled contaminated water. They are always a step behind so that is why we can’t trust them,” Suzuki said, as his trawler, the Ebisu Maru, traveled before dawn to a point about 45 kilometers (30 miles) offshore from the Fukushima plant to bring back a test catch.

With his father at the wheel, Suzuki dropped the heavy nets out the back of the boat, as the black of night faded to a sapphire sky, tinged orange at the horizon.

As the sun rose over a glassy sea, father and son hauled in the heavily laden nets and then set to the hard work of sorting the fish: sardines, starfish, sole, sea bream, sand sharks, tossing them into yellow and blue plastic baskets as sea gulls screamed and swooped overhead.

Five hours later, the Ebisu Maru docked at Yotsukura where waiting fishermen dumped the samples into coolers and rushed them to a nearby laboratory to be gutted and tested.

Suzuki says his fisheries co-operative will decide sometime soon whether to persist in gathering samples.

For now they will have to survive on compensation from the government and Tokyo Electric Power Co., the plant’s operator.

The cooperative also had plans to start larger-scale test catches next month that would potentially also be for consumption if radiation levels were deemed safe.

But those plans were put on hold after more bad news last week: authorities discovered that a massive amount of partially treated, radioactive water was leaking from tanks at Fukushima, the fifth and so far the worst, breach.

The water, stored in 1,000 tanks, is pumped into three damaged reactors to keep their melted fuel cool. Much of the water leaked into the ground but some may have escaped into the sea through a rain-water gutter.

On Wednesday, the Nuclear Regulation Authority upgraded its rating of the leak to a “serious incident,” or level 3, up from a level 1 on the international scale of the International Atomic Energy Agency.

It remains unclear what the environmental impact from the latest contamination will be on sea life. Scientists have said contamination tends to be carried by a southward current and largely diluted as it spreads.

Nobuyuki Hatta, director of the Fukushima Prefecture Fisheries Research Center, said the trend had been positive before the latest leaks, with fewer fish found exceeding radiation limits.

The government’s safety limit is 100 becquerels per kilogram, but local officials have set a stricter bar of 50 becquerels, said Hatta, who still expects test fishing to resume in September.

It all depends on the type of fish, their habitat and what they eat. Out of 170 types of fish tested, 42 fish species are off limits due to concern they are too radioactive, another 15 species show little or no signs of contamination. Few, if any, show any detectable levels of cesium.

Tests take over a month and are complicated. The time lag makes it difficult to say at any given point if sea life caught off the Fukushima coast is really safe to eat.

Also, local labs lack the ability to test fish for other toxic elements such as strontium and tritium. Scientists say strontium should be particularly watched for, as it accumulates in bones. TEPCO’s monitoring results of sea water show spikes in strontium levels in recent weeks.

Suzuki has little faith in the future of his business.

“People in the fishing business have no choice but to give up,” he said. “Many have mostly given up already.”

___

Associated Press writers Elaine Kurtenbach and Mari Yamaguchi in Tokyo contributed to this report.

Radioactive Water Leaking From Fukushima Into Pacific Ocean, TEPCO Says

This aerial photo taken on July 9, 2013 shows reactor buildings Unit 2, left, and Unit 1 at Fukushima Dai-ichi nuclear power plant in Okuama, Fukushima Prefecture, northern Japan. Japan’s nuclear regulator says radioactive water from the crippled Fukushima power plant is probably leaking into the Pacific Ocean, a problem long suspected by experts but denied by the plant’s operator. (AP/Kyodo News)

This aerial photo taken on July 9, 2013 shows reactor buildings Unit 2, left, and Unit 1 at Fukushima Dai-ichi nuclear power plant in Okuama, Fukushima Prefecture, northern Japan. Japan’s nuclear regulator says radioactive water from the crippled Fukushima power plant is probably leaking into the Pacific Ocean, a problem long suspected by experts but denied by the plant’s operator. (AP/Kyodo News)

By Freya Petersen, Source: Mint Press News

The operator of the crippled Fukushima Daiichi nuclear power plant, Tokyo Electric Power Company (TEPCO), on Monday admitted that radioactive groundwater had leaked out to Pacific Ocean, fueling fears of contamination.

Earlier this month TEPCO said groundwater samples taken at the Fukushima showed levels of possibly cancer-causing caesium-134 had shot up more than 110 times in a few days, Australia’s ABC reported.

In July, Russia Today reported, Japan’s nuclear watchdog — the Nuclear Regulation Authority (NRA) — stated that it ”strongly suspected” contamination of ground waters and possibly the Pacific Ocean.

TEPCO did not know the exact reasons for the increased readings, but initially said the radioactive groundwater was likely contained by concrete foundations and steel sheets.

“But now,” TEPCO spokesman Masayuki Ono told a news conference, ”we believe that contaminated water has flown out to the sea.”

However, Ono insisted that the impact on the ocean would be limited:

“Seawater data have shown no abnormal rise in the levels of radioactivity.”

The March 2011 earthquake and tsunami off Japan’s coast knocked out cooling systems at the Fukushima plant, triggering fuel meltdowns and causing radiation leakage, food contamination and mass evacuations.

Radioactive substances have since made their way into underground water, which usually flows out to sea.

This article originally was published at Global Post.