Thu, 19 Jul 2012 10:45 CDT
Little-known statistics compiled by Japan’s Fisheries Agency have documented persistently high post-Fukushima radiation levels in fish.
Are fish from the Pacific Ocean and Japanese coastal and inland waters safe to eat 16 months after the Fukushima nuclear disaster?
Governments and many scientists say they are. But the largest collection of data on radiation in Japanese fish tells a very different story.
In June, 56 percent of Japanese fish catches tested by the Japanese government were contaminated with ce-sium-137 and -134. (Both are human-made radioactive isotopes – produced through nuclear fission – of the element cesium.)
And 9.3 percent of the catches exceeded Japan’s official ceiling for cesium, which is 100 becquerels per kilogram (Bq/kg). (A becquerel is a unit of radioactivity equal to one nuclear disintegration per second.)
Radiation levels remain especially high in many species that Japan has exported to Canada in recent years, such as cod, sole, halibut, landlocked kokanee, carp, trout, and eel.
Of these species, cod, sole, and halibut, which are oceanic species, could also be fished by other nations that export their Pacific Ocean catch to Canada.
The revelations come from the Japanese Fisheries Agency’s radiation tests on almost 14,000 commercial fish catches in both international Pacific and Japanese waters since March 11, 2011, when an earthquake and tsunami triggered multiple meltdowns at the Fukushima Daiichi Nuclear Power Plant.
The wrecked plant spewed enormous amounts of radiation into the Pacific, where cesium levels near the Fukushima coast shot up to an astonishing 45 million times the pre-accident levels.
Japan’s Fisheries Agency data is easily the most comprehensive on Fukushima’s radioactive impacts on the Pacific Ocean, home to the world’s biggest fishery and a major food source for more than a billion people.
The numbers show that far from dissipating with time, as government officials and scientists in Canada and elsewhere claimed they would, levels of radiation from Fukushima have stayed stubbornly high in fish. In June 2012, the average contaminated fish catch had 65 becquerels of cesium per kilo. That’s much higher than the average of five Bq/kg found in the days after the accident back in March 2011, before cesium from Fukushima had spread widely through the region’s food chain.
In some species, radiation levels are actually higher this year than last.
The highest cesium level in all of the catches came in March – a year after the accident – when a landlocked masu salmon caught in a Japanese river was found to have a whopping 18,700 becquerels of cesium per kilogram – or 187 times Japan’s ceiling.
Burnaby MD Tim Takaro says he now avoids eating fish from the vicinity of Japan. “I would find another source for fish if I thought it was from that area,” said Takaro, an associate professor in Simon Fraser University’s faculty of health sciences.
“There are way too many questions and not enough answers to say everything is fine,” Takaro said in a phone interview. “There is a need for monitoring. There isn’t any question in my mind about that.”
Takaro is a member of the Canadian antinuclear group Physicians for Global Survival, which joined five other Canadian and international medical and environmental groups last week to issue a statement calling on the B.C. Centre for Disease Control, Ottawa, and U.S. authorities to monitor Pacific migratory fish and seafood imports from Japan and other nations that ply the Pacific with their fishing fleets.
“Doing this kind of monitoring is a fundamental responsibility of governments,” said Vancouver MD Erica Frank, who spearheaded the statement.
“People shouldn’t have to worry about radiation levels in the food they eat.”
Frank – a Canada Research Chair in UBC’s faculty of medicine and a past president of the Nobel Prize – winning U.S. group Physicians for Social Responsibility, another signatory of the statement – said she also avoids eating fish from Japan.
“I think it’s important to ask purveyors of Pacific food where it comes from,” she said.
Nicholas Fisher is one of the few U.S. scientists studying Fukushima’s impacts on migratory fish in the Pacific.
Fisher said he was surprised when told about the high cesium levels in the Japanese fisheries data. It makes him leery of eating fish from Japanese waters, he said.
“Those are high numbers. It would give me pause if I were eating fish in Japan….Imported fish are also a concern,” said Fisher, a marine-sciences professor at New York’s Stony Brook University. Fisher added in a phone interview that the persistently high cesium numbers may be a sign that the Fukushima plant is still leaking radiation into the ocean.
Trying to limit your radiation exposure from fish? Governments haven’t given much information on which species were hardest hit, but the Japanese data gives good clues.
Yet it has gotten virtually no notice from journalists or scientists in North America.
The data shows the contamination has remained high in both saltwater species and freshwater fish found in Japanese lakes and rivers. Especially high cesium levels have been found in recent months in these saltwater species: halibut (a catch in May 2012 had 570 Bq/kg), sole (a catch in January had 180 Bq/kg), and cod (a catch in February had 260 Bq/kg).
All of these catches exceed Japan’s 100 Bq/kg ceiling for cesium in food, but none would have surpassed Canada’s much higher ceiling, which is 1,000 Bq/kg. Freshwater species such as trout, carp, and (landlocked) masu and kokanee salmon have also recently shown very high cesium levels, as have eels, which live in both fresh and salt water. Also troubling: except for sole and cod, all of these species had their highest cesium readings in 2012, not 2011.
A big question here is the fate of the salmon. Some migratory B.C. salmon stray into Japanese waters or could traverse a vast mass of radioactive water – now slowly making its way eastward across the Pacific – which is expected to reach the North American west coast by 2017, extending from Vancouver Island southward to Baja California (according to a July 9 report in Environmental Research Letters).
The Japanese data tells us a little about how some salmon species were affected.
Half of the 10 coho salmon tested since the Fukushima disaster were contaminated with cesium. One coho caught in Japanese coastal waters last October had 114 Bq/kg of cesium, surpassing Japan’s ceiling. Chum salmon, on the other hand, showed much less contamination than coho, with only nine of 257 chum catches since the accident testing positive for cesium. The highest amount detected was eight Bq/kg in a catch last November.
Among the hardest-hit fish species are landlocked salmon. Every one of the 42 kokanee (a landlocked sockeye salmon) tested since March 2011 had at least some cesium contamination. Japan exported $430,000 of kokanee to Canada in the first four months of 2012, according to Statistics Canada figures.
A kokanee with 200 Bq/kg was caught in April of this year, according to the Japanese data. In both May and June, kokanee with 180 Bq/kg were caught.
But the record for most cesium in all the fish catches was handily set by the landlocked masu salmon (native to the Western Pacific) that registered 18,700 Bq/kg in March.
Statistics Canada data shows Japan exported $37,000 worth of “Pacific, Atlantic, and Danube salmon” to Canada in the first four months of 2012.
Agriculture and Agri-Food Canada spokesperson James Watson said by phone from Ottawa that his department doesn’t know if Canada has imported masu salmon from Japan.
The Canadian Food Inspection Agency said in a July 17, 2012, statement that Canada has imported one shipment of masu salmon, in October 2011, since Fukushima. The statement says the product was processed in the U.S., the shipment’s country of origin was not disclosed by the importer, and the product was not tested for radiation. (Masu salmon is also found in other parts of East Asia.)
CFIA spokesperson Lisa Gauthier refused to make someone available to answer questions on fish monitoring.
Japanese finance ministry trade data, however, shows Japan exported 120 kilograms of masu salmon to Canada in April 2011, directly after the nuclear accident.
The test data does have some better news for other species. Tuna, octopus, and anchovies (as well as seaweed) have all seen declining cesium levels since last winter after much higher contamination in the six to nine months after the accident. Even so, however, 69 percent of anchovies still had some cesium contamination in June (the highest level was 5.5 Bq/kg), and so did 32 percent of tuna (the highest reading was 1.9 Bq/kg).
Cesium levels in tuna could still go up as they become more exposed to radioactive water near Japan, said Stony Brook University’s Fisher.
Fisher cowrote a study in May 2012 in the Proceedings of the National Academy of Sciences that reported that of 15 Pacific bluefin tuna caught off the California coast, all had radioactive cesium from Fukushima. The tuna had an average of 10.3 Bq/kg when they were caught last August.
The amounts are below government ceilings, but government regulators and scientists generally agree that no amount of radiation is safe.
For example, Canada’s ceiling for radiation is set at a level that allows 5,000 to 8,000 cancers per million people over a 70-year lifetime of exposure, according to Health Canada’s models and those of a landmark 2006 U.S. National Academy of Sciences report on cancer risk from radiation. (About half of the cancers would be fatal.)
Health Canada’s ceilings for chemical carcinogens are generally set at levels that cause a maximum of one to 10 lifetime cancers per million people.
Authorities in Canada dismiss the calls for monitoring.
“Not involved, not involved,” said Tom Kosatsky, the B.C. Centre for Disease Control’s acting medical director of environmental health services, when asked about monitoring of radiation in Pacific fish.
“It’s a federal responsibility,” he said in a phone interview.
In the past, the CFIA has said it has no plans to monitor Pacific fish or imports from Japan and other countries whose fishing fleets plumb the Pacific.
The agency briefly monitored Japanese food imports from the vicinity of Fukushima after the accident, but ceased the tests in June 2011. It also did radiation tests on a dozen fish caught in B.C. coastal waters last August and another 20 in February 2012, finding no cesium, according to the CFIA website.
The B.C. Seafood Alliance’s Christina Burridge said in a phone interview last January that she was surprised the CFIA wasn’t doing more tests.
She said the agency last year promised her group, an umbrella of Pacific seafood-harvesting associations, that it would test Pacific salmon and tuna returning to B.C. waters in 2012 and 2013 because those fish may have migrated close to Japan.
Burridge couldn’t be reached for comment by press time.
Meanwhile, Japan’s seafood exports to Canada seem to be growing despite Fukushima and reports that the accident kneecapped the Japanese fishing industry.
Japan exported $6.9 million of fish and crustaceans to Canada in the first four months of 2012, according to Statistics Canada, which would work out to $20.7 million per year if averaged. That would be up from $16.3 million in 2011, which itself was higher than the 2010 total of $15.4 million.
Other nations are growing more leery of Japanese seafood. In June, South Korea temporarily banned the import of 35 Japanese seafood products – such as flatfish, clams, and sea urchins – due to radiation concerns, adding to a list of 29 other Japanese seafoods that the country had banned earlier.
It all leaves Vancouver doctor Frank bewildered by the government response here.
“It struck me as such a poor public-health decision not to monitor. This requires urgent action, but it just doesn’t seem to register on anyone’s radar,” she said.
Frank is now writing a book about the struggle to get authorities to monitor fish after Fukushima. She said she thinks of it as a murder mystery. “There are no bodies, but as a specialist in preventive medicine, I worry about increased mortality from the fish,” she said.