The fish off Fukushima remain radioactive more than a year after the earthquake and subsequent tsunami triggered three meltdowns at the Daiichi nuclear power plant. In fact, bottom-dwelling greenling fish caught in August 2012 bore the highest levels of radioactive particles seen to date—25,000 Becquerels per kilogram. (A becquerel is a unit of the rate of radioactive decay—or radiation emitted by a substance.) That is 250 times higher than current Japanese safety standards, a key reason fishing off Fukushima remains prohibited.

The findings suggest that contaminated water is still leaking from the stricken power plant, the sea bottom itself is now laced with radionuclides, or both. Concentrations in the ocean water itself remain below any human health concern but they do pass into fish that swim through those waters.

"When fish 'drink' they take [cesium] and other salts up from the water they are swimming in, that accumulates in the muscle tissue," explains marine chemist Ken Buessler of the Woods Hole Oceanographic Institution, who compiled the analysis of publicly released Japanese fisheries data and published it in Science on October 26. But the fish also shed that cesium if they swim in uncontaminated waters, as has been seen in tuna that migrated from near Japan to near San Diego, suggesting that levels in fish should decrease over time. For this reason, most of the fish caught off Japan's northeastern coast are not radioactive. But roughly 40 percent of bottom-dwelling fish, such as flatfish or halibut, caught off the coast adjacent to Fukushima bear radionuclides above the Japanese food safety standard of 100 becquerels per kilogram.*

According to a response to questions from Scientific American that was prepared by staff at the U.S. Nuclear Regulatory Commission, ingesting fish at that level "would only produce a dose that is a small fraction of the dose that people receive from natural levels." For example, as Buessler notes, fish caught off Japan in June 2011 boasted levels of potassium-40—a naturally occurring radionuclide—10 times higher than those of radioactive cesium from Fukushima.

Radioactive cesium decays by emitting what's known as a beta radiation, a negatively charged particle that is easily blocked by metal, plastic or wood—but not skin. In particular, ingesting beta-emitting radioactive elements is "a concern," according to the NRC. "Beta particles released directly to living tissue can cause damage at the molecular level, which can disrupt cell function." Plus, beta particles are small enough to travel far in the body, causing damage far and wide.

U.S. safety guidelines from the Food and Drug Administration permit foods to bear 1,200 becquerels per kilogram of radioactive cesium, but the FDA declined to comment for this article. "The more restrictive action taken by the Japanese seems reasonable for the population living close to Fukushima because they receive radiation doses from other sources, including non-fish food, drinking water and land surface contamination," the NRC staff writes. "Based on the FDA and [World Health Organization] recommendations, eating fish contaminated at 100 Bq/kg would result in a small and acceptable exposure to radioactive cesium."

6 Comments

1. 1. sethdiyal 01:16 PM 10/26/12

   
   I always get a kick out of how the Georgia Straight links to these blatent junk science antinuclear articles but blocks all informed commentary that disputes its own Big Oil junk science motivated articles on the same subject.
   
   " As of April 2012, fish can only be sold in Japan if it contains less than 100 becquerels of caesium 134 and 137 in seafood per kilogram of wet weight, down from a previous limit of 500 becquerels... this was not because scientific advice had changed, but because the government wanted to reassure people"
   
   Bananas are 130 per kilogram. Maybe they should be banned in Japan too.
   
   " ..According to... staff at the U.S. Nuclear Regulatory Commission, ingesting fish at that level "would only produce a dose that is a small fraction of the dose that people receive from natural levels." For example, as Buessler notes, fish caught off Japan in June 2011 boasted levels of potassium-40—a naturally occurring radionuclide—10 times higher than those of radioactive cesium from Fukushima.
   
   "U.S. safety guidelines from the Food and Drug Administration permit foods to bear 1,200 becquerels per kilogram of radioactive cesium,"
   
   The Big Oil corrupted Japanese government is now spending $5B on fiscal stimulus when they are wasting $100B per annum on increased imports of Big Oil's filth because the scared bunnies are afraid of already paid for nuclear. This despite having upgraded their formerly publicly approved corrupt nuclear regulatory system (everything in Japan is corrupt) that caused FUKU in the first place to IAEA standards.
   
   Now these stupid nitwits are killing not only their economy but almost as many as died in the Tsunami event every year with fossil fuels and its massive air pollution, because their nukes sit idle. Big Oil has been paying off their corrupt politicians and media to spin stupid never never land promises of a future powered by wind and solar soon they can continue to rip them off for decades into the future.
   
   With their industry moving production offshore to China with dirt cheap nuke electricity on the rise, Japan is doomed.

   Reply | Report Abuse | Link to this

2. 2. Profitsup 03:19 PM 10/26/12

   How does this compare to the testing over the decades in the Pacific test areas of the USA and the French governments for decades?
   
   The USA test area is now safe for human occupation? Seems that panic issue statements do not progress real research and knowledge. It appear to be the pushing for panic and new grant money . . .

   Reply | Report Abuse | Link to this

3. 3. Asteroid Miner 12:29 AM 10/27/12

   573 certified deaths were due to evacuation-related stress at Fukushima.  Zero due to radiation.  February 4, 2012
http://www.beyondnuclear.org/home/2012/2/4/japanese-authorities-recognize-573-deaths-related-to-fukushi.html
    
   "Japanese authorities recognize 573 deaths related to Fukushima Daiichi Nuclear Catastrophe
   As reported by the Yomiuri Shimbun:
   "A total of 573 deaths have been certified as "disaster-related" by 13 municipalities affected by the crisis at the crippled Fukushima No. 1 nuclear power plant....
   A disaster-related death certificate is issued when a death is not directly caused by a tragedy, but by fatigue or the aggravation of a chronic disease due to the disaster. ....""
    
   ZERO deaths were caused by radiation.  573 deaths were caused by the evacuation that was forced by officials.  The people who died were evacuated from such things as intensive care.  They might have survived if the evacuation had not taken place.  Fukushima's natural background radiation is still higher than the radiation from the reactor leak.  Fukushima's natural background radiation plus the radiation from the reactor leak is still less than the natural background radiation here in Illinois.  Natural background radiation varies greatly from place to place.  Our background radiation is around 350 milli rem/year.
   "milli" means ".001"
   350 milli rem/year means 0.350 rem/year
   1 rem = 10 millisievert
   People living in Ramsar, Iran have a background radiation of 10 to 20 rems/years.  Ramsar is a city in Iran.  
    
   Here are some natural background readings from "Power to Save the World; The Truth About Nuclear Energy" by Gwyneth Cravens, 2007:   
   Guarapari, Brazil:  3700 millirem/year
   Tamil Nadu, India:  5300 millirem/year
   Ramsar, Iran:  8900 to 13200 millirem/year
   Denver, Colorado   1000 millirem/year
    
   A not entirely natural reading:
   Chernobyl:  490 millirem/year
    
   Some background reading:
   http://en.wikipedia.org/wiki/Background_radiation
   http://www.unscear.org/unscear/en/publications/2000_1.html
    
   62% of Japan's electricity comes from coal fired power plants.   Coal contains so much uranium and thorium that we could get all of the uranium we need from coal cinders and ash.   Coal fired power plants put all of it either up the stack or into the solids that are hauled away.    
   http://www.ornl.gov/info/ornlreview/rev26-34/text/colmain.html
    
   Calculate your annual radiation dose:
   http://www.ans.org/pi/resources/dosechart/
   
   

   Reply | Report Abuse | Link to this

4. 4. Asteroid Miner 12:31 AM 10/27/12

   Please read this book: "Radiation and Reason, The impact of Science on a culture of fear" by Wade Allison.
   http://www.radiationandreason.com/
   Professor Allison says we can take up to 10 rems per month, a little more than 1000 times the present "legal" limit. The old limit was 5 rems/lifetime. A single dose of 800 rems could kill you, but if you have time to recover between doses of 10 rems, no problem. It is like donating blood: You see "4 gallon donor" stickers on cars. You know they didn't give 4 gallons all at once. There is a threshold just over 10 rems. You are getting .35 rems/year NATURAL background radiation right where you are right now.
   
   Divide 5 rems by your present Natural Background Radiation. For Americans, Natural Background Radiation is at least .35 rems/year. Our Natural Background Radiation uses up our 5 rems/lifetime when we are 14 years old.
   
   Natural Background Radiation is radiation that was always there, 1000 years ago, a million years ago, etc. Natural Background Radiation comes from the rocks in the ground and from exploding stars thousands of light years away. All rocks contain uranium. Radon gas is a decay product of uranium.
   

   Reply | Report Abuse | Link to this

5. 5. Profitsup in reply to Asteroid Miner 08:06 AM 10/27/12

   Granite as used in Churches and home kitchens gives off radiation - so do natural granite boulders we all like to picnic among - shame on us for we are exposing our families to more radiation than escaped from 3 mile island . . [source - speech from the Dean of the School on Mines in Reno Nevada]

   Reply | Report Abuse | Link to this

6. 6. dwbd 12:04 PM 10/27/12

   Pure Bull. Big Oil's disinformation service running in high gear. Major news services, like CNN are flashing subtitles "Radiation still high near Fukushima Daiichi Nuclear plant". Notice you hear ZIP in Big Oil's mainstream media about the FAR, FAR higher radiation from TEN'S OF THOUSANDS of Big Oil's Fracking wastewater ponds, which is unregulated, and they can dump into our water supply even though:
   
   "..as high as 267 TIMES the limit safe for discharge into the environment and THOUSANDS OF TIMES the limit safe for people to drink.."
   
   My emphasis. That makes Japan's max 250X reading in this ONE tiny location, look pretty minor doesn't it, with Japan's already stringently low permissible radiation standards.
   
   www.propublica.org/article/is-the-marcellus-shale-too-hot-to-handle-1109
   
   So the Japanese hypocrites are taking this holier than though attitude about Nuclear Energy safety, meanwhile according to OECD stats they are killing an avg of about 300 people per year in accidental deaths, due to the higher death rate of fossil fuel production & delivery over Nuclear. That's just accidental deaths, not including the ten's of thousands of increased emissions related deaths.
   
   But that is not the end of the story on Japan's hypocrisy. Japan was given an exemption on the Iran Oil Export Embargo. They whined "we need the Oil" i.e. they need Oil to replace some of that lost Nuclear Generation. So the sleazy Japanese gov't even paid a $7.6B insurance fee in order to get tankers to deliver it Oil from Iran. So now the Japanese are busily financing Iran's Nuclear Weapons program, Japanese yen buying Nuclear bombs for Iran, with the bomb program in the final stages of development. Helping that, of course, is the exports of high tech equipment form the other No-Nukes country, Germany - Hypocrites #2. Much of Iran's centrifuge tech and machine tools for their weapons program is German.
   
   So the most likely source of the next ACTUAL NUCLEAR EXPLOSION is an Iranian atomic bomb, paid for by Japan. Maybe detonated in an American city, paid for by Japan. So much for the minor zero-death Fukushima radiation.
   
   Here, I thought the Japanese were big on honor. Well, I would say their behavior is the epitome of dishonor. Bending down to the ground to lick the boots of Big Oil, kowtowing to its anti-Nuclear Power agenda, while completely ignoring other VASTLY more serious radiation, nuclear and public health & safety issues. Just as Big Oil demands.
   
   The Japanese must hang their head in shame over what they have done - National Harri-Kari?

   Reply | Report Abuse | Link to this