Fukushima Fallout Not Affecting U.S.-Caught Fish

Bluefin tuna is among the species that have been found to contain trace amounts of radioactive particles from teh failed nuclear reactors at Fukushima. (Photo by Stewart Butterfield)

This article was originally published by the Center for American Progress.

In recent weeks, there has been a significant uptick in news from Fukushima, Japan. Officials from the Japanese government and the Tokyo Electric Power Company, or TEPCO, admitted that radioactive water is still leaking from the nuclear plant crippled by the 2011 earthquake and tsunami.

The new revelations about the amount of water leaking from the plant have caused a stir in the international community and led to additional scrutiny of Pacific Ocean seafood. Last week, South Korea announced it had banned all imports of Japanese seafood from a large area around Fukushima. And Al Jazeera reported that the cost to the region’s fishing industry over the past two years exceeds $3.5 billion.

Now, fears are mounting that the radiation could lead to dangerous contamination levels in seafood from more of the Pacific Basin. Numerous blog posts and articles expressed concern about the potential for higher concentrations of radioactive particles, particularly in highly migratory species such as tuna that may have encountered Fukushima’s isotopes—including highly dangerous and toxic materials such as cesium-137, strontium-90, and iodine-131—on their transoceanic travels.

Amid alarmist outcry and opposing assurances that the radiation levels in fish are no more harmful than what’s found in the average banana, I decided to dig a little deeper, and a few weeks ago, I posted a brief analysis on Climate Progress. After reading the comments on that piece, it became clear I needed to do a bit more homework.

I began by going straight to the source: Dr. Ken Buesseler, senior scientist in marine chemistry and geochemistry at the Woods Hole Oceanographic Institution. When I reached Dr. Buesseler by email, he was literally on his way out the door for a flight to Japan, where he is currently continuing his research on precisely this issue. But he took a moment to read my post and respond. His reaction:

I like [your] line
Let’s be clear: leaked radiation is bad. This is a problem that needs urgent, international attention. But at least for now, I’m happy to reassure Joe Romm and all the parents of Facebook: your fish are not glowing with Fukushima radiation. Eat up!

Dr. Buesseler also pointed me to a Fukushima FAQ page on his department’s website that he set up to answer the influx of questions he has received on this particular issue.

In the context of seafood consumption, the most important thing to determine is the potential degree of harm that can come to someone who eats fish that may contain higher-than-normal quantities of potentially dangerous isotopes. This begs a few specific questions:

1. How much radiation is out there?
2. Where is it?
3. What concentrations are harmful to humans?

And of course:

4. Seriously? Radioactive bananas?

How much radioactive water are we talking about?

Last month, the Japanese government reported that the Fukushima plant was leaking approximately 300 tons, or 71,895 gallons, of contaminated water each day. That’s a lot of water—except when you compare it to the Pacific Ocean, which is estimated to contain 187,189,915,062,857,142,857 gallons. That’s 187 quintillion for those counting at home. So as a quick comparison, even if the site continues leaking 72,000 gallons per day for 10 years, the total amount spilled would be 262.8 million gallons. This is a tall drink of water to be sure, but it is still just .00000000014 percent of the volume of the Pacific Ocean. Of course, any amount of leaked radiation is bad, so we’ll get to the part about exactly how bad this stuff is in a minute.

It’s also likely that additional water could seep, or is already seeping, from various other containment devices—hence the news that Japan will construct ice dams or other containment structures to help hold back the radioactive flow. In short, this kind of engineering nightmare makes BP’s months-long struggle to plug the Macondo oil gusher in the Gulf of Mexico in 2010 look like a People magazine crossword puzzle (13 across: Skywalker pal Han ____).

Containing Fukushima radiation is not likely to be resolved anytime soon, so:

Where is the radiation going?

According to Dr. Buesseler’s FAQ:

The spread of cesium once it enters the ocean can be understood by the analogy of mixing cream into coffee. At first, they are separate and distinguishable, but just as we start to stir the cream forms long, narrow filaments or streaks in the water. The streaks became longer and narrower as they moved off shore, where diffusive processes began to homogenize and dilute the radionuclides.

Dr. Buesseler and others have suggested that radionuclides will reach U.S. shores “some time in late 2013 or 2014” but that “at the levels expected even short distances from Japan, the Pacific will be safe for boating, swimming, etc.”

Some studies predict that over the next 5 to 10 years, concentrations on the North American Pacific Coast could actually be higher than those off Japan, but the total amount of radioactivity will be well below the current levels near the crippled nuclear plant because of dilution throughout the Pacific Basin.

Should we be worried about the quantities found in our fish?

It goes without saying that we should monitor our seafood and water quality with extreme care. As for the specifics of what to look for, we turn again to Dr. Buesseler:

Seawater everywhere contains many naturally occurring radionuclides, the most common being polonium-210. As a result, fish caught in the Pacific and elsewhere already have measurable quantities of these substances. … cesium [forms] a salt taken up by the flesh that will begin to flush out of an exposed fish soon after they enter waters less affected by Fukushima. By the time tuna are caught in the eastern Pacific, cesium levels in their flesh are 10-20 times lower than when they were off Fukushima.

Cesium will still be more concentrated in larger, carnivorous fish higher up the food chain, such as bluefin tuna than in smaller fish with diets consisting more of plankton and algae, but because it will “flush out” of the fish’s flesh, concentrations will not necessarily mount over time.

An area of greater concern to Buesseler is the increasing quantity of strontium-90 detected in the waters near Fukushima. Unlike cesium, strontium accumulates in bone rather than muscle, and it is not rapidly flushed from the fish. The good news here is that aside from consumers of small fish such as sardines, which are eaten bone-in, most diners will not be eating strontium.

How is the federal government testing Pacific Ocean seafood?

The lead U.S. agency testing seafood for contamination is the Food and Drug Administration, or FDA. As of June 20, the FDA has tested 1,313 samples of food imported from Japan, including 199 seafood samples. Of those, just one—a sample of ginger powder—exceeded the level considered safe for consumption.

When contacted about its testing of domestically caught seafood, an FDA spokesman responded in an email, saying that “the FDA is not aware of any evidence suggesting that the domestic seafood catch contains harmful levels of radiation.” He further referenced a 2012 study from the Proceedings of the National Academy of Sciences, which found levels of cesium-137 and cesium-134 in bluefin tuna to be, according to an email from the FDA, “roughly 300 times lower than levels that would prompt FDA to investigate further to determine if there were a health concern.”

How does nuclear waste differ from the radiation from a banana?

Nuclear radiation exists in many places in our daily lives. Perhaps the most commonly cited example is the average, everyday banana.

Bananas have enough naturally occurring radiation that science communicators developed a metric called the Banana Equivalent Dose, or BED, as a means of explaining in user-friendly terms how much radiation a given thing emits. The BED represents the amount of radiation the body receives from eating one banana and roughly equates to 0.1 nanoseiverts. A seivert is the unit used to measure exposure. An arm x-ray is equivalent to 10 BED. A flight from New York to London: 400 BED. A chest CT scan: 70,000 BED. A fatal dose is roughly 80 million BED. Most of the radiation in bananas comes from potassium-40, which is processed naturally by the body, but some of it arrives in the form of polonium-210, the isotope used in a massive dose to kill former KGB agent Alexander Litvinenko in 2006.

Of course, the radiation in bananas is different from what’s in leaked nuclear wastewater. For starters, while bananas’ radioactivity occurs naturally, nuclear waste contains isotopes, including cesium-137, which are exclusively and deliberately generated by human activity—specifically, the process of nuclear fission.

Radiation released in the decay of radioactive isotopes is classified in three types—alpha, beta, and gamma—and each type has different strengths and properties. Banana radiation—potassium and polonium—is alpha radiation, while cesium and strontium fall in the strongest category, gamma rays. The radioactive particles also have different half-lives—a half-life is the amount of time it takes for 50 percent of a given compound to decay. The half-life of cesium-137 is 30 years; for polonium-210, it is 138.4 days.

So while eating a serving of Pacific bluefin tuna will expose someone to roughly one to five BED, according to a paper Buesseler and his colleagues published in the Proceedings of the National Academy of Sciences in late 2012, that does not mean the potential harm is the same as eating a handful of bananas. But so far, according to Dr. Buesseler and the FDA, we have no reason to fear the amount of radiation in domestically caught fish.

Recall that cesium-137 and other affiliated nasty particles have been part of our lives in varying quantities since the first nuclear tests occurred in the 1940s and ‘50s. While the Fukushima release represents a major influx of the material to the natural environment, when it comes to ocean contamination, it still represents little more than a drop in the proverbial bucket. At least for now, except for fish from the immediate area around the Fukushima plant, Pacific Ocean seafood remains safe to eat.

Michael Conathan is the Director of Ocean Policy at the Center for American Progress.

Michael Conathan is the Director of Ocean Policy at the Center for American Progress.
  • imagoddess2


  • Erik S.

    The whole banana comparison thing is completely false… humans can naturally offset this type of radiation but the hot particles being released by Fukushima are deadly to humans… this article should be retracted… what a joke!

  • Jessica

    So with the Government shut down . If its the Federal Government that test our seafood. Wonder if they are going to shut that down. They have already shut our national state Parks down. A change needs to be done to protect our American dream, The land of the free.

  • admin

    thank you all for not buying the propaganda, sham on you nat geo you crony kissers, wonder who runs this mag and what are the connections???

  • Hillary

    I really want there to be a non-profit, pro-people agency that will monitor all food sources for Fukushima contamination so that those interested or concerned can actually find correct and non-bias info about what is safe and not safe for consumption. I will dream on…

  • Dan

    I actually think this is great. It should lower the demand for blue fin tuna & help the population recover.

  • PJK


  • Peter Koedyk

    When we eat bananas the radioactive potassium is flushed out by our bodies. When we ingest strontium 90 it accumulates in our bones and organs, transmitting radiation at 20 million times the rate or radioactive potassium while it remains in our body, exposing us to the high radiation on a daily basis for the rest of our lives.. so yes this is a big thing.. and the same counts for cesium, although the body does flush out this element to a certain extend. Anyway, just a tiny bit of strontium 90 or cesium 134 or 137 will do harm to your DNA in the long run..

  • Greg Kellett

    Well this has made for a very worrying yet interesting read and I was wondering if any official spokesman for NatGeo had anything to say on this matter?

  • patie millen

    Bravo people on not buying this rubbish. I am so relieved when i see that all but two posters know this is completely false reporting. Stay safe people.

  • RC

    The media, governments and Tokyo Energy are all lying in regards to the safely of the radiation in the Pacific and the life forms that live there. The deaths of sea animals washing up on the US shorelines is proof of the dangers lurking in the pacific for all life forms.

    Shame on THEM for misleading humanity for greed and power sake. Human lives and the lives of all wild species in the sea are far more important than a companies bottom line!

    Interesting to see the spin occurring the disinformation people.

  • Giovanni

    NatGeo has sponsors just like the dishonest network news.
    The world oceans have been used as a toilet for too many centuries. I hope that the extraterrestrials that have been visiting Earth can teach we children not to play with technologies that we haven’t mastered.

  • mike

    I am so glad that you all are on to the scam perpetrated by these ‘scientists’ what with their PhD’s and their other elitists titles. Why, everyone knows that radiation is bad for you, and if some egghead does a bunch of so-called research and tries to arrive at a reasonable conclusion based on the data available, and then tries to communicate that conclusion to the public in terms that a third grader could understand, and that scientist’s conclusion doesn’t corroborate your deepest fears, then he/she must be in on the conspiracy. I bet all those so-called ‘scientists’ own stock in fishing boats, or they are getting paid off by the gubmint to spread propaganda, or well… something, because everybody knows that radiation is bad, even those of you who don’t know what radiation is specifically. It’s just bad OK, and you don’t need any freshman physics to know when you are being lied to. Seriously, I love sushi, and I hope all you ill-informed goobers succeed in driving the price down to the point I can poison myself silly with cesium 137.

  • Rosa

    It will kill plankton and that’s just the beggining

  • archie

    Am I on the wrong comment page?? Where the dillio are all ‘a the folk with words of “praise the fishies and hallelujah, Lets Eat!!”?? Am I missin somethin here??

  • procomptor

    I THINK THE BIGGEST QUESTION TO ASK HERE IS; Why was the acceptable level of radiation to the human body recently raised?

    It is my understanding that after the accident the US government had these acceptable levels raised. ALSO. WHY IS THERE NO TALK HERE ABOUT THE RADIATION NOW IN RAIN WATER, SNOW AND THE AIR WE BREATH.

    Must think people are stupid. Pacific ocean water no matter where it is located condenses to rain and those clouds are carried hundreds of miles before they dump (usually along the coast and inner valleys. What about the radiation in all this???

  • Chris
  • Michelle

    Does anybody have a solution? Like what can be done to support your health or the health of others? Dwelling in the problem only grows the problem. We are so quick to disagree. I found this post looking for a solution. I suggest aquaponics initially. Now what natural support can I use to help my body deal with the neo-environmental state. All the talk about corporate greed, do you use a bank? How are you supporting the current economic system. Look within family of man…

  • Bet Young

    It is always reassuring to say let’s eat unfortunately it is also a cliche. I like the comment the writer wrote saying this is serious. Let’s expound on that. Let’s hear from some West Coast scientists as well on what we don’t know and if we are wrong what are the consequences. A friend recently said she had 4 friends die of cancer. I know it is not connected, and also know this is our concern esp for infants, etc. While saving face let’s continue to do research and be preventative and cautionary.

  • Alex

    You know.. Oceans are my life. I dive every day, a lot of it in the Pacific Islands, from Micronesia to Indonesia. I see the populations of fish and all marine creatures decimate by the week. And I can’t help thinking WE DID THIS. And there is no stopping it. So maybe things like tsunamis and earthquakes that damage our nuclear plants are Mother Nature’s way to control the HUMAN POPULATION. Ever look at yourselves and think.. ‘crap, we’re the bad guys on this planet’? We beat every other thing Earth had on us,we’re even getting better at battling cancer. But we just don’t give a shit about anything else.
    I agree with Mike, the plankton will go first. Without plankton all of fish in the ocean will die, radiation or not. Without plankton the oxygen levels will drop and we will die. Harsh isn’t it? Well, suck it up. We did this to ourselves.

  • Joel Stabile

    Its so bad they cant even report about it on the news. Not one word about any single thing about it. There are 70 US Navy personnel that unknowingly showered and drank water from Fukashima ocean water that the ship took in right after the disaster. they had come to the aid of the Tepco. The corp failed to tell them they were in grave danger They now they have leukemia, they cant walk, their organs are failing some are in wheel chairs and some are dead.
    There are sailors who claim the paint is changing color being eaten off the boats that have sailed for years with no previous change.. One sailor commented its awfully quiet he saw only one whale spinning sores on its head why would people lie about this.
    Coral dies off when too many pesticides are washed into the ocean from mainland rain you think radiation and uranium aren’t going to be devastating? Why havent we poured cement and concrete over the entire plant and save whats left if anything. Nuclear power is no way to boil water! We already know its not worth the risk. The Tepco Corp has lied from the beginning. Yea lets go ahead eat the fish and please keep it off the news there is no danger the news wont even report that! We are never going to be able to come back from this. The single worst accident its gonna affect everyone.

  • raven

    It has been proven that the Japanese lied to down play the truth of their nuclear reactor disaster which will eventually also poison the earth for so many years to come.

    Has anyone noticed how quiet the news media is now? It is as though a complete black out was enacted, and this is public knowledge.

    Our human lives, the lives of our children and all of our future generations mean nothing if Corporate and Government greed does not continue to profit financially.

    Imagine the horror if everything affiliated with the seafood, fishing, and ocean related industries were to stop producing. Financial greed knows no bounds.

    From what many have witnessed now in 2014 is that we of the human race, and all other species can all drop dead of radiation poisoning, and for many not to even truthfully acknowledge what has occurred, and what is expected for many years to come from all of this radioactive fall out which poisoned not only all the oceans, but our air, and total environment leaves so many unanswered questions.

    The general public are not fools. Since when is raising the acceptable levels of radiation from the lower numbers of years ago, to the much higher numbers since this Japanese Nuclear Plant Radiation disaster occurred become acceptable????

    Do an internet search to see photographs of radioactive fish caught by fisherman in the oceans and brought to shore to be photographed. Also look at all the photographs of the sea creatures which have washed ashore with missing eyes, lesions, blood oozing from open sores and gills, and horrible discolorations. For sure these poor creatures mush have died a very painful death. (A photo is worth a thousand words, and that alone speaks volumes for the truth).

    The bottom line and the truth now stand as such:
    Do we eat anything caught from any ocean on the Earth in 2014, and is it safe to eat and feed to our children?
    I know one thing that is what seems to be the billion dollar questions………..and I also know Human Life is priceless as is mine and the lives of my children…..what about yours?

    May God help us now……

  • rizza

    I hope everyone who disagrees with this article is smart enough to disagree with this fake “Measels outbreak” crap. Every one of you don’t believe this guy and say why would we trust japan doing there own tests… well why do we trust the vaccine companies to do there own test? you guys alow yourself to be injected with MERCURY and other peoples DNA and your afraid of a lil Sr-90… come on people whats really killing this country isn’t nuclear reactors which are perfectly safe during operation and if you watch Pandoras promise you will learn more about that. the real problem is eating pesticide, cleaning your house and washing yourself with poison every day and allowing yourself to be injected with poison. More people die from solar energy then they do from nuclear energy. the oil and coal companies love you idiots because you are taking away the only affordable, renewable, clean energy that can actually compete with them. GO NUCLEAR.

  • rizza

    Also a scintillation detector is worthless to see the low quantities of radionuclides in these fish. you need a gamma spec. be ready to spend 20K from Canberra. if you are all really that worried take yourself to Carlsbad NM to the NM State college where they have a whole body counter which will see small quantities of radionuclides. bring a few fish with yea. they will tell you that if you eat any wild game you will most likely have a lil Cs-137 in yea from nuclear fallout. I work with hundreds of people who have been exposed to 30+ REM in there life and all are perfectly healthy because the govt sets these limits so low. you will volunteer to go get a random chest xray and not think twice because hey the doctor cant have anything to gain from u financially right? you are all sheep. fall in line idiots the govt wants u to freak out over nuclear power because they want to make money off oil.

About the Blog

Researchers, conservationists, and others share stories, insights and ideas about Our Changing Planet, Wildlife & Wild Spaces, and The Human Journey. More than 50,000 comments have been added to 10,000 posts. Explore the list alongside to dive deeper into some of the most popular categories of the National Geographic Society’s conversation platform Voices.

Opinions are those of the blogger and/or the blogger’s organization, and not necessarily those of the National Geographic Society. Posters of blogs and comments are required to observe National Geographic’s community rules and other terms of service.

Voices director: David Braun (dbraun@ngs.org)

Social Media