Inside the slow and dangerous clean up of the Fukushima nuclear crisis

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JUDY WOODRUFF: Now we take you to a place that garnered headlines around the world three years ago, but has hardly been seen since, because it’s so dangerous.

Is it possible to make a negative $ contribution to PBS? The February 28th PBS Newshour on Fukushima is shocking. Imagine a script written by Arnie Gunderson and Helen Caldicot, designed to create maximum fear and anxiety. 

Hiroshima Syndrome has posted a March 4th critique titled PBS Fukushima Report is Fear-mongering at its Worst which begins:

The February 28 PBS report, Inside the slow and dangerous clean up of the Fukushima nuclear crisis, is fear-mongering at its most disturbing extreme. The obvious intent is to scare and upset the viewer with exaggeration, innuendo, and thinly-veiled conspiracy theory, all predicated on proliferating fear, uncertainty and doubt. (FUD) There seems to have been little or no effort towards rational informing of the viewers.

Even the lead-in by anchor Judy Woodruff drips with fear and doubt, “Now we take you to a place that garnered headlines around the world three years ago, but has hardly been seen since, because it’s so dangerous.” Hardly seen since? Who is she trying to kid? Fukushima has been in the Japanese Press every day for three years, and the internet has been inundated with apocalyptic scenarios made by leading international antinukes on a regular basis. Plus, what about the Fukushima radioactivity reporting coming out of the Pacific coastline of North America the past two months? “Hardly seen”? Give me a break. In addition, the implication that the Press in Japan isn’t covering Fukushima “because it’s so dangerous” is a complete fabrication! They are all over it… like white on rice.

The report itself begins with end-of-the-world insinuations by PBS’ Miles O’Brien, when he says the evacuation zone around F. Daiichi “remains a post-apocalyptic landscape of abandoned towns, frozen in time. We were on our way to one of the most hazardous places on Earth, the Fukushima Daiichi nuclear power plant.” Who wrote the script? Harvey Wasserman? Arnie Gundersen? Helen Caldicott? This is straight out of the antinuclear persuasion’s “Fukushima 101” rhetorical guidelines. The apocalyptic beginning follows with a quote from the plant manager posed in a fashion that makes it seem as if he is not taking his job seriously enough, “After all, if you are just cleaning up after an accident, there is a lack of quality, meaning speed is the only concern. I feel that isn’t enough. We need to look ahead, 30 to 40 years.”

Next comes two misleading statements – “Engineers believe some of the nuclear fuel has melted right through the steel containment vessels on to a concrete basement floor, where it is exposed to groundwater.” (Which it isn’t) – “As the ground water passes through the pump, it gets mixed in with the contaminated water that is used to cool the melted-down cores.” (What is O’Brien talking about? What pump? How is the pump mixing the waters? Is he making this up, or does he simply not have a clue?)

Read the whole thing…

The REAL reason some people hate nuclear energy

I heard Carl Sagan argue today (in a Science Friday archival interview from May 1996) that entrenched-power is not motivated to encourage critical thinking in the population. I’m afraid Dr. Sagan hit the bulls-eye on that one – the political logic is obvious. 

Today I also read Martin Nicholson’s new and important article at BraveNewClimate on human misperception of risk. Martin’s essay is based on David Ropeik’s essential book How Risky Is It, Really? Human evolution did not prepare us at all for a world where we must make choices amongst imperfect alternatives that have complex future consequences. Evolution did not select for skill at making decisions with century-time-scale impacts. Nor for choosing between alternative risk-benefit pairings. The beginning of Martin’s concluding section makes this clear:

Closing the Perception Gap

Making policy decisions based on fears rather than facts can lead to decisions that feel good (e.g. no nuclear) but increase the overall risk to the population (more deaths and health risks from burning fossil fuels and climate risks from greenhouse gas emissions).

Ropeik tells us that risk perception is an intrinsic, biologically rooted, inescapable part of how the human animal behaves. We need to accept this and use what we know about the way humans respond to risk in order to help ourselves make better, healthier choices. We need to bring the risk perception factors out of the subconscious shadows and use them as practical tools to allow our rational thinking to have more influence in the process.

We need to keep an open mind and give ourselves time to get more information from neutral and reliable sources – those that have no obvious bias. We need to consider all components of our response to the risk – not just the facts. We need to consider the pros and cons of various risk-management options. Why not factor feelings and values into the equation instead of trying to factor them out? Think about which policies will do us the most good.

Poor risk communication from government or agencies that are supposed to protect us like the International Atomic Energy Agency (IAEA) or the World Health Organization (WHO) can sometimes fail to account for people’s risk perceptions. This was a key factor in the long-term social/psychological/economic consequences of Chernobyl. A similar situation may have occurred at Fukushima.

Unfortunately, “feel good” is the most salient feature of politically successful policies. How does this connect to Carl Sagan’s argument? Only our critical thinking skills can save us from “feel good”. One thing we know for sure is that it is rare in western education systems to see critical thinking encouraged.   Read Martin’s essay, you’ll be glad you did.

Fukushima: WHOI senior scientist studies North Pacific Ocean effects

WHOI senior scientist Ken Buesseler

WHOI senior scientist Ken Buesseler began his career in oceanography by studying the spread of radionuclides from Chernobyl in the Black Sea. Not surprisingly, today one of his research interests is the impact of Fukushima contaminants in the North Pacific Ocean. Ken and the WHOI staff have been investing a lot of personal time in science communication — to help the general public better understand whether they need to be worried about Fukushima effects.

Our Radioactive Ocean: Recently they launched the remarkable new website ourradioactiveocean.org. This is almost a “one stop shop” for accurate and accessible information on radioactivity and our oceans. The site is also the home of CMER’s crowd-sourced project to sample and analyze North Pacific Ocean waters. The crowd-sourcing innovation seems to be getting off to an encouraging start — you can see the current results here

CMER Pacific Ocean monitoring

Anyone (you?) can propose a sampling location, take samples of 20 liters of sea water, ship it to CMER at WHOI for analysis – and help raise the funds for the procedure (beginning with the expensive shipping). The fund raising is especially important as Ken’s lab already has more samples than they have budget to analyze. Excerpt from their crowd-sourcing page:

There currently is no U.S. or international agency monitoring the arrival of radioactive water from Fukushima along the West Coast. Although we don’t expect levels to be dangerously high in the ocean or in our seafood as the plume spreads across the Pacific, this is an evolving situation that demands careful, consistent monitoring to make sure predictions are true.

We at the Woods Hole Oceanographic Institution already have dozens of seawater samples from the coast of Japan out to the middle of the Pacific, but now we need new samples—from up and down the West Coast of North America and anywhere else we can get them. The trouble is, these samples are expensive to collect and analyze. That is why we are turning to you, your community, and your social network for help.

If you want to propose a sampling location near you, all you have to do is raise the cost of testing and shipping ($550 to $600 depending on location) and we will send you a sampling kit with everything you need. We’ll also help by setting up a fundraising webpage that you can email to your friends or post on your favorite social media site that will allow you to spread the word and track your progress.

Once you have your kit, sampling is easy (see video). When we get your sample, we will add it to the queue of samples to be analyzed. This isn’t a quick process (it takes 24-48 hours just to measure the radiation in a sample after processing), but we will fast-track samples from people like you. Depending upon how many are ahead of yours, however, it may take 5 to 10 weeks before we send you an email with the results and post your data on our interactive map.

In November 2013 Cape Code Online published a short interview with Dr. Buesseler, where he discussed the new Pacific monitoring initiative:

(…snip…) He predicts the radiation will be so diluted after the long journey across the Pacific that it will pose no threat to American fisheries or recreational activities.

“It’s very much a coastal Japan contaminant problem,” Buesseler said.

But he knows that’s not enough to reassure the public.

Given what’s happened at Fukushima, Buesseler asked, “Wouldn’t you want to have some measurement?”

This effort is science-motivated. But I think there is a science-education benefit that could be important. I predict that the  monitoring results will prove conclusively that the hysteria about the “Fukushima killing the Pacific Ocean” was hype, not science. And these are not results published by “them”, the results will clearly be produced by caring individuals in a completely transparent process. It make another generation to turn around the public radiophobia, but this looks like a solid contribution.

On Twitter you can see the latest updates on the Pacific monitoring project by following @whoi_cmer. Read Ken’s new paper Oceanography paper Fukushima and Ocean Radioactivity {if that link expires, search on the citation: Buesseler, K.O. 2014. Fukushima and Ocean Radioactivity. Oceanography 27(1), http://dx.doi.org/10.5670/oceanog.2014.02}.

Here are some related Seekerblog posts on the public health risks associated with Fukushima contamination. In particular I suggest starting with these:

Do we need to worry about Fukushima contamination in the ocean? (part 1)

Fukushima, radiation and risk: what is scary and what is not

Fukushima contamination “poses no risk” to U.S. West Coast

Tony Barboza writing for the LA Times has a straightforward and accurate account of U.S. West Coast real risks associated with Fukushima contamination. Not every media source is spreading fear, Mr. Barboza is doing an excellent job of sourcing information from real experts such as Nicholas Fisher of Stony Brook University, Kim Martini of University of Washington, and Ken Buesseler, of Woods Hole Oceanographic Institution. Excerpts:

Radiation detected off the U.S. West Coast from the Fukushima Daiichi nuclear plant in Japan has declined since the 2011 tsunami disaster and never approached levels that could pose a risk to human health, seafood or wildlife, scientists say.

Experts have been trying to dispel worries stemming from a burst of online videos and blog posts in recent months that contend radiation from Fukushima is contaminating beaches and seafood and harming sea creatures across the Pacific.

Those assertions are false and the concerns largely unfounded, scientists and government officials said last week, because Fukushima radionuclides in ocean water and marine life are at trace levels and declining — so low that they are trivial compared with what already exists in nature.

“There is no public health risk at California beaches due to radioactivity related to events at Fukushima,” the California Department of Public Health said in a statement.

Even at its worst in the months after the disaster, the dose of radioactivity that Fisher's lab found in tuna caught off California was far lower than what people are exposed to from medical X-rays or eating bananas or other potassium-rich foods, which contain naturally occurring radioactive isotopes.

The latest concerns are mostly driven by online videos, blogs and social media — including a post titled “28 Signs That the West Coast Is Being Absolutely Fried With Nuclear Radiation From Fukushima.”

Kim Martini, an oceanographer at the University of Washington, noticed a surge in outrageous worries about radiation in Seattle last fall, including people who were afraid to go to the beach and stopped eating seafood.

“Every single environmental issue was being blamed on Fukushima,” she said. “And I thought there's no way that can be true.”

Since then she and other scientists have been posting information on the blog Deep Sea News, with posts including “Is the sea floor littered with dead animals due to radiation? No.”

A magnitude 9.0 earthquake off Japan on March 11, 2011, triggered a series of tsunamis that crippled the Fukushima Daiichi nuclear power plant, releasing radiation into the ocean and atmosphere. Studies show that leaks from the facility continue to send radionuclides into the sea. But they dilute quickly in ocean water, scientists say.

Once those contaminants disperse across the Pacific Ocean and reach the West Coast, their concentration will be many thousands of times lower and not of concern, according to an online FAQ by Ken Buesseler, a marine scientist at the Woods Hole Oceanographic Institution.

“This is not to say that we should not be concerned about additional sources of radioactivity in the ocean above the natural sources, but at the levels expected even short distances from Japan, the Pacific will be safe for boating, swimming, etc.,” Buesseler wrote.

Good job Tony!

 

What scientific idea is ready for retirement? Answer LNT

At Edge.org John Brockman posed the Edge question 2014 “What scientific idea is ready for retirement?“. There are a number of important short essays in reply to the question. I want to highlight Stewart Brand’s essay nominating The Linear No-Threshold Radiation Dose Hypothesis:

 

STEWART BRAND
Author and founder of The Whole Earth Catalog; co-founder of The Well and The Long Now Foundation

In his 1976 book, A Scientist at the White House, George Kistiakowsky, President Eisenhower’s science adviser, told us what he wrote in his diary in 1960 on being exposed to the idea by the Federal Radiation Council:

It is a rather appalling document that takes 140 pages to state the simple fact that, since we know virtually nothing about the dangers of low-intensity radiation, we might as well agree that the average population dose from manmade radiation should be no greater than that which the population already receives from natural causes; and that any individual in that population shouldn’t be exposed to more than three times that amount, the latter figure being, of course, totally arbitrary. Later in the book, Kistiakowsky, who was a nuclear expert and veteran of the Manhattan Project, wrote: “… a linear relation between dose and effect… I still believe is entirely unnecessary for the definition of the current radiation guidelines, since they are pulled out of thin air without any knowledge on which to base them.”

Sixty-three years of research on radiation effects have gone by, and Kistiakowsky’s critique still holds. The linear no-threshold (LNT) radiation dose hypothesis, which surreally influences every regulation and public fear about nuclear power, is based on no knowledge whatever.

At stake are the hundreds of billions spent on meaningless levels of “safety” around nuclear power plants and waste storage, the projected costs of next-generation nuclear plant designs to reduce greenhouse gases worldwide, and the extremely harmful episodes of public panic that accompany rare radiation-release events such as Fukushima and Chernobyl. (No birth defects whatever were caused by Chernobyl, but fear of them led to 100,000 panic abortions in the Soviet Union and Europe. What people remember about Fukushima is that nuclear opponents predicted that hundreds or thousands would die or become ill from the radiation. In fact nobody died, nobody became ill, and nobody is expected to.)

The “linear” part of the LNT is true and well documented. Based on long-term studies of survivors of the atomic bombs in Japan and of nuclear industry workers, the incidence of eventual cancer increases with increasing exposure to radiation at levels above 100 millisieverts per year. The effect is linear. Below 100 millisieverts per year, however, no increased cancer incidence has been detected, either because it doesn’t exist or because the numbers are so low that any signal gets lost in the epidemiological noise.

We all die. Nearly a half of us die of cancer (38% of females, 45% of males). If the “no-threshold” part of the LNT is taken seriously, and an exposed population experiences as much as a 0.5% increase in cancer risk, it simply cannot be detected. The LNT operates on the unprovable assumption that the cancer deaths exist, even if the increase is too small to detect, and that therefore “no level of radiation is safe” and every extra millisievert is a public health hazard.

Some evidence against the “no-threshold” hypothesis draws on studies of background radiation. In the US we are all exposed to 6.2 millisieverts a year on average, but it varies regionally. New England has lower background radiation, Colorado is much higher, yet cancer rates in New England are higher than in Colorado – an inverse effect. Some places in the world, such as Ramsar in Iran, have a tenfold higher background radiation, but no higher cancer rates have been discovered there. These results suggest that there is indeed a threshold below which radiation is not harmful.

Furthermore, recent research at the cell level shows a number of mechanisms for repair of damaged DNA and for ejection of damaged cells up to significant radiation levels. This is not surprising given that life evolved amid high radiation and other threats to DNA. The DNA repair mechanisms that have existed in yeast for 800m years are also present in humans.

The actual threat of low-dose radiation to humans is so low that the LNT hypothesis can neither be proven true nor proven false, yet it continues to dominate and misguide policies concerning radiation exposure, making them grotesquely conservative and expensive. Once the LNT is explicitly discarded, we can move on to regulations that reflect only discernible, measurable medical effects, and that respond mainly to the much larger considerations of whole-system benefits and harms.

The most crucial decisions about nuclear power are at the category level of world urban prosperity and climate change, not imaginary cancers per millisievert.

 

Fukushima, radiation and risk: what is scary and what is not

Thanks to Randall XKCD http://what-if.xkcd.com/29/

The purpose of this post is to communicate why the more you know about radiation the less you worry about nuclear radiation – even the consequences of the terrible accident at Fukushima Daiichi.

To get your skeptical circuits warmed up, let's begin with the above graphic, an excerpt from Randall Munroe's What-If XKCD where Randall “answers your hypothetical questions with physics, every Tuesday”.

What if I took a swim in a typical spent nuclear fuel pool? Would I need to dive to actually experience a fatal amount of radiation? How long could I stay safely at the surface?

Randall's exploration of the question is a useful introduction to how to think about risk and radiation dose – in relation to intensity, exposure time and mediation medium (water in this example). Randall begins

Assuming you’re a reasonably good swimmer, you could probably survive treading water anywhere from 10 to 40 hours. At that point, you would black out from fatigue and drown. This is also true for a pool without nuclear fuel in the bottom.

After you've enjoyed “Spent Fuel Pool“, I recommend Randall's Radiation Dose Chart, which has become a frequently-cited resource for an introduction to radiation dose and risk. The chart is useful for an overview of relative magnitudes. In addition to Randall's chart I recommend that you download for your archive Natural Radioactivity, published by the physics department of Idaho State University. That is “ground truth” on the details of background radiation in the oceans, or land – lots of numbers and units.

With that gentle introduction I hope you are ready to read some resources that go into Fukushima monitoring in a bit more detail. Are you worried about contamination from the Fukushima Daiichi reactors? E.g., turning the Pacific Ocean into a place too dangerous to swim? Too dangerous to eat the Blue Fin Tuna?

First you will find your hard data at Monitoring environmental radiation Nuclear Regulation Authority (NRA), Japan. In particular, you can find the weekly Sea Area Monitoring reports. As I write the latest report is for 10 December, 2013 (PDF).

To make sense out of all the Becquerels/Litre in the NRA tabulations I recommend Putting Fukushima in Perspective: A primer on radioactivity in the Ocean written by University of Victoria marine chemist Jay T. Cullen (@JayTCullen). Dr. Cullen is investing his personal time in science communication to inform the public about the real risks associated with contamination from the Fukushima site. From his primer article:

Talk of plumes of radioactivity being broadcast across the Pacific must take into account that the background radioactivity of seawater is about 14 Bq/L. It is important that although one can detect isotopes from the reactor in the environment the absolute levels are very low and will be lower as the ocean mixes, and the isotope decays.

Dr. Cullen is using 14 Bq/L as the global ocean radioactivity – what does that mean? Well, one Becquerel is that quantity of a radioactive material that will have 1 transformations in one second. So the unit Bq/L tells us there is a concentration of radioactive elements in each litre of ocean that emits at the rate of 1 count per second (cps). We don't know what the material is, but we know a Geiger counter would detect 14 counts/second from a typical litre of sea water. And we know empirically (by swimming in the stuff, eating the Tuna, etc.) that 14 Bq/L is perfectly safe. Even if we don't know exactly what the number means.

Click the thumbnail for full size graphic

So let's examine some of the extensive NRA monitoring, which publishes weekly sampling results from sites immediately around the Fukushima Daiichi breakwater, out to open ocean. The thumbnail to the left shows the worst/highest sample values for Cs-134 and Cs-137 that I could find in the open sea zone (full size).

In the next table I have compared the worst samples to typical ocean background radiation. What we see is that dilution and decay of the cesium isotopes has already reduced the radiation to levels that are insignificant in relation to normal. That indicates that US Pacific coast residents do not need to be alarmed.

 

Some like to use the radioactivity of a banana to make these units more familiar. A typical banana emits about 15 Bq due to the potassium isotope K-40. So radiation-wise eating a banana is similar to drinking a litre of typical ocean, ignoring retention rates. If you are comfortable with bananas and seawater, but are still concerned about the Fukushima contribution, think of it this way. Equivalent to eating that banana, you would have to drink between 3 and 6 cubic meters of pure water contaminated with the measured concentrations of Fukushima cesium. I think I prefer to get my radiation dose from the banana, but I appreciate they are equivalent.

But what about concentration of the insignificant levels by fish and mollusks into dangerous levels if consumed? Good question. I asked the same question, which led me back to Dr. Cullen again for the analysis of that issue, titled What Controls Levels of Fukushima Radioisotopes in Marine Organisms?

Scientists normally report the amount of a radioactive element in an organism in units of concentration where the mass or activity of the radionuclide is given relative to the weight of the organism or its tissue. The units of these measurements are, therefore, either kilogram (kg) or activity in Becquerel (Bq = disintegrations per second) divided by the mass of the organism or tissue (kg/kg or Bq/kg). We want to understand how much radionuclide ends up in the organism relative to the isotopes concentration in seawater which can be reported in either kg per liter of seawater or Bq per liter of seawater (kg/L or Bq/L). By determining the ratio of the concentration of a radionuclide in an organism to the concentration of the isotope in seawater we define the Concentration Factor (CF) which has units of L/kg:

concentrationperunitmass.png

So if the CF for an element in a given organism is a very high number then that radioisotope tends to bioaccumulate and is found at higher concentrations in the organism than in the surrounding marine environment. Conversely, if the CF is low there is little risk of bioaccumulation in the organism.

So what is the bottom line on seafood?

What can we expect on the west coast of North America?

Beginning in the new year we can expect seawater affected by the Fukushima disaster to arrive at our coast in the Pacific northwest. Peak concentrations in the heart of the plume of affected seawater are expected to be on the order of 0.001 to 0.020 Bq/L based on measurements and physical models of ocean circulation. The much lower radionuclide concentrations are the result of mixing and the decay of shorter lived isotopes. Given known CFs for marine organisms these seawater concentrations will result in much lower concentrations of radionuclides in organisms residing on the west coast compared to their Japanese cousins. The radioactive dose to these organisms or consumers of these organisms will be dominated by the naturally occurring radionuclide Po-210.

A confirming evaluation of the food chain question was published in the June 25, 2013 issue of the Proceedings of the National Academy of Sciences Evaluation of radiation doses and associated risk from the Fukushima nuclear accident to marine biota and human consumers of seafood [open access]. Excerpt from the abstract:

To link the radioactivity to possible health impairments, we calculated doses, attributable to the Fukushima-derived and the naturally occurring radionuclides, to both the marine biota and human fish consumers. We showed that doses in all cases were dominated by the naturally occurring alpha-emitter 210Po and that Fukushima-derived doses were three to four orders of magnitude below 210Po-derived doses. Doses to marine biota were about two orders of magnitude below the lowest benchmark protection level proposed for ecosystems (10 µGy⋅h−1).

My bottom line is — if you wish to monitor for any dangers developing when Fukushima seaborne contamination reaches California, then I suggest you subscribe to Dr. Cullen's blog MarineChemist. That's what we do (we subscribe to his RSS feed). If there is anything to worry about then Dr. Cullen will let you know. Or you can just subscribe to Seekerblog!

I promised to also discuss “what is scary?” My answer is the post-antibiotic world where antibiotics don't work any more. That is really, really scary, especially if you are a geezer like me. Climate change is very scary – but antibiotic resistance is spreading as I write. The big hurts from climate change will probably be after-death experiences for me.

Japanese Fisheries Agency samples fish for contamination: most OK “even in the sea near Fukushima”

Japanese Fisheries Agency samples fish for contamination: most OK “even in the sea near Fukushima”
Source Japan Times

The officials from the Fisheries Agency stressed that the monitoring results show that the impact of the nuclear crisis on fish is now subtle even in the sea near Fukushima.

Results from the cesium density test in the first three month after the meltdown catastrophe started in March 2011 showed that 53 percent of fish caught around Fukushima exceeded the legal limit of 100 becquerels per kilogram, but now only 2.2 percent of fish caught top this threshold. Regardless, fish caught within 20 km of Fukushima No. 1 are not shipped to market.

As for fish caught far from Fukushima, more than 14,000 samples have been tested in the past year and only 88 exceeded the legal cesium safety limit of 100 becquerels per kilogram.

Fukushima water leaks:“This is healthwise a big nothing”

Lake Barrett, a former head of the Department of Energy’s Office of Civilian Nuclear Waste Management, spent nearly a decade at the U.S. Nuclear Regulatory Commission and led the clean-up operations after the 1979 partial meltdown at the Three Mile Island nuclear plant. He has been brought in by Tokyo Electric Power (Tepco) to advise it on the lengthy decommissioning process at Fukushima.

He said work should begin now to pump groundwater from the plant before it reaches wrecked reactors – a measure that has been stalled by local opposition.

“They should start pumping as soon as practical,” said Barrett, adding that groundwater would have to be released into the sea along with water that had been treated to remove most radiation – by a system designed by Toshiba Corp.

“I believe in a matter of a few months … early next year … water will be cleaned up and be ready to be discharged,” he said in an interview.

But Barrett, who has said he would feed his grandchildren fish caught off the Fukushima coast if the clean-up proceeds as planned, said Tepco has lost its credibility to reassure a jittery public. “When Tepco says: ‘trust me, this water is safe,’ that’s not enough,” he said.

(…) He said concerns raised by South Korea and China over the continued leaks of radiated water at Fukushima “political posturing.”

“This is healthwise a big nothing,” he said.

Source

 

Do we need to worry about Fukushima contamination in the ocean? (part 1)

In a word, no – though it isn't a good idea to eat the bottom fish feeding within a few kilometers of the Daiichi harbor. And if you made your living fishing in the ocean right around Daiichi, your livelihood has been destroyed until the cleanup is completed. While there are serious threats that deserve our intense focus, Fukushima is not anywhere on my list, which starts with antibiotic resistance, energy poverty, and climate change. But turn on a TV anywhere and you will soon see newsreaders talking about radiation leaking from Fukushima Daiichi into the Pacific Ocean. If there are any numbers mentioned they will be Very Big Numbers voiced to make it clear these are unbelievably scary.

On the other hand, talk to any scientist familiar with radiation health physics: they will be unconcerned, but monitoring. Why is it that the level of fear is inversely proportional to understanding? In brief, it is because with understanding comes the appreciation that life is adapted to the levels of ionizing radiation common around the planet. Those background levels vary by more than an order of magnitude, and surprisingly, residents of the areas with highest background radiation do not have elevated levels of cancer. So radiation is not scary, unless the dose exceeds the tolerance of our DNA repair systems. To put the numbers and units in an easy to grasp frame, please spend some time absorbing the brilliant relative radiation chart developed by XKCD. For reference, keep in mind an annual dose limit of roughly 50 mSv (here is some background on exposure limits at the Health Physics Society).

Since the current focus of fear is Fukushima I've gathered a few science resources that I hope will help the reader lose at least those particular fears. First we have scientist Ken Buesseler, with Woods Hole Oceanographic Institution. Ken maintains a Woods Hole website FAQ: Radiation from Fukushima. Ken's most recent update is 28 August:

On March 11, 2011, a magnitude 9.0 earthquake—one of the largest ever recorded—occurred 80 miles off the coast of Japan. The earthquake created a series of tsunamis, the largest estimated to be over 30 feet, that swept ashore. In addition to the tragic human toll of dead, injured, and displaced, the earthquake and tsunamis badly damaged the Fukushima Daiichi nuclear power plant, eventually causing four of the six reactors there to release radiation into the atmosphere and ocean.

Since mid-2011, I have worked with Japanese colleagues and scientists around the world to understand the scope and impact of events that continue to unfold today. In June 2011, I organized the first comprehensive, international expedition to study the spread of radionuclides from Fukushima into the Pacific, and I or members of my lab have participated in several other cruises and analyzed dozens of samples of water, sediment, and biota. In addition, I began my career in oceanography by studying the spread of radionuclides from Chernobyl in the Black Sea. These are a few of the most common questions that people have been asking me lately.

-Ken Buesseler, Woods Hole Oceanographic Institution.

What is the state of fisheries off Japan and along U.S. West Coast?

The coastal fisheries remain closed in Japan near Fukushima, where there is a concern for some species, especially the bottom dwelling ones, which are being tested and many have been found to be above the Japanese government's strict limits for cesium in seafood. These contaminated fish are not being sold internally in Japan or exported. Because of the dilution that occurs even a short distance from Fukushima, we do not have a concern about the levels of cesium and other radionuclides in fish off the West Coast of the U.S.

More about the state of Japanese fisheries (pdf).

Are fish such as tuna that might have been exposed to radiation from Fukushima safe to eat?

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. Most fish do not migrate far from home, which is why fisheries off Fukushima remain closed. But some species, such as the Pacific bluefin tuna, can swim long distances and could pick up cesium in their feeding grounds off Japan. However, cesium is 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. Moreover, the dose from Fukushima cesium is considered insignificant relative to the dose from naturally occurring polonium-210, which was 1000 times higher in fish samples studied, and both of these are much lower relative to other, more common sources, such as dental x-rays.

More about the dose and associated risk (pdf) of radiation from Fukushima to marine life and humans.

(…)Is radiation exposure still a concern?

Is radiation exposure still a concern? I stood on a ship two miles from the Fukushima reactors in June 2011 and as recently as May 2013, and it was safe to be there (I carry radiation detectors with me) and collect samples of all kinds (water, sediment, biota). Although radioactive isotopes in the samples and on the ship were measurable back in our lab, it was low enough to be safe to handle samples without any precautions. In fact, our biggest problem is filtering out natural radionuclides in our samples so we can measure the trace levels of cesium and other radionuclides that we know came from Fukushima.

Where does radiation from Fukushima go once it enters the ocean? 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. In the ocean, diffusion is helped along by ocean eddies, squirts, and jets that broaden, mix, and continue to dilute the cesium as it travels across the ocean. With distance and time, radionuclide concentrations become much lower in the ocean, something that our measurements confirm.

More information about our oceanographic studies off Fukushima (pdf).

Are the continued sources of radiation from the nuclear power plants of concern?

The site of the Fukushima Dai-ichi nuclear power plant is an ongoing source of radionuclides (pdf) in to the ocean “something I've seen evidence of in my data and published about since 2011. Although the numbers sound large (300,000 gallons of water leaked or 20 trillion bequerels per liter), we calculated in 2011 when radiation levels were much higher than today that the dose to someone on a ship or in the ocean was not of concern. For the workers at the site, direct exposure from leaking storage tanks is of greater health concern because exposure from these concentrated sources is much higher. For the general public, it is not our direct exposure, but uptake by the food web and, hence, the potential for human consumption of contaminated fish that is the main health concern.

Will radiation be of concern along U.S. and Canadian coasts? Levels of any Fukushima contaminants in the ocean will be many thousands of times lower after they mix across the Pacific and arrive on the West Coast of North America some time in late 2013 or 2014. This is not to say that we should not be concerned about additional sources of radioactivity in the ocean above the natural sources, but at the levels expected even short distances from Japan, the Pacific will be safe for boating, swimming, etc.

Is debris washing ashore on the US/Canadian West Coast of concern? Debris washed out to sea by the tsunami does not carry Fukushima radioactive contamination”I‚Äôve measured several samples in my lab. It does, however, carry invasive species, which will be of serious concern to coastal ecosystems on the West Coast.

Have there been increased deaths as a result of radiation from Fukushima?

Reports of increased deaths are simply not true. Read this reasoned response in Scientific American to the most often-cited “scientific” paper about erroneously linking deaths to radiation from Fukushima. That article ends “This is not to say that the radiation from Fukushima is not dangerous (it is), nor that we shouldn't closely monitor its potential to spread (we should).” I agree with that statement.

Where can people go for reliable information?

Here are some other links I have passed to others. Fukushima's Radioactive Water Leak: What You Should Know http://news.nationalgeographic.com/news/energy/2013/08/130807-fukushima-radioactive-water-leak/

Latest Radioactive Leak at Fukushima: How Is It Different? http://news.nationalgeographic.com/news/energy/2013/08/130821-fukushima-latest-leak-how-is-it-different/

See also following article from the Woods Hole Oceanographic Institution (w/ links to many others) http://www.whoi.edu/oceanus/viewArticle.do?id=167749&sectionid=1000 From the special issue of Oceanus Magazine devoted to the cause and impacts of Fukushima: http://www.whoi.edu/oceanus/series/fukushima

Consider supporting our new Center for Marine and Environmental Radioactivity and check out CMER public education links, such as ABCs of radioactivity http://www.whoi.edu/page.do?pid=119836

Last updated: August 28, 2013

I'm working on a followup post that is intended to provide a reference set of resources to help readers get comfortable with radiation and risk.

 

Paul Blustein: Everything you thought you knew about the risks of nuclear energy is wrong

Brookings scholar Paul Blustein reviews Pandora’s Promise from Kamakura, Japan:

Chances are pretty high, based on prevailing public opinion, that you will think my wife and I are a tad crazy, maybe even guilty of child abuse. During the March 2011 accident at the Fukushima Dai-ichi nuclear plant, which is a couple hundred miles from where we live, we stayed put while thousands of others fled the Tokyo area and many foreigners left Japan for good. Not only that, we buy as much of our fruits and vegetables as possible from Fukushima Prefecture, the Connecticut-size jurisdiction where the plant is located (we even specially order boxes of Fukushima produce) while millions of others in Japan take extreme care to consume only food from the far west and south of the country. And yes, our whole family, including our 12- and 10-year-old sons, eats Fukushima food. We’re convinced it’s perfectly safe, and we like helping people whose products suffer from an unjust taint.

Are you recoiling in horror, perhaps even wishing the Japanese child welfare authorities would seize custody of our kids? If so, you are the ideal audience member for a provocative new film, titled Pandora’s Promise. This documentary focuses on five thoughtful environmentalists who were once terrified of radiation, and thought nuclear power was imperiling the planet’s future, but after educating themselves, they gradually realized that their assumptions were wrong. For people who are instinctively opposed to nuclear power but open-minded enough to consider evidence that goes against their predilections, this film will, and should, force them to question their certitude.

(…snip…) 

As someone who had to learn about radiation in a hurry after Fukushima, I was gratified to see how the educational process worked with these five environmentalists. Stewart Brand, founder of The Whole Earth Catalog, recalls being bewildered at first by the plethora of radiation exposure measurements (in millirems, microrems, millisieverts, microsieverts etc.). “You’re looking and squinting. ‘Okay, that looks like a large number. Is that a number I should worry about?’ Compared to what? What’s the background radiation level relative to all this?”

Like me, the enviros in the film were astonished to come across extensive evidence about the minimal physiological impact of contamination from major nuclear accidents. The best example is Chernobyl, where the radiation emissions in 1986 were by far the largest in history; nearly three decades later, studies show that the main effects on the general population in the area have overwhelmingly been on the mental and emotional health of people who thought they were doomed to cancer and succumbed as a result to maladies such as depression and substance abuse. (The chief documented exception is the 6,000-odd cases of thyroid cancer contracted by children after drinking milk from cows fed on grass contaminated with radioactive iodine. Soviet authorities failed to warn people of this danger, though only a handful of the victims have reportedly died of the ailment, which is one of the least lethal forms of cancer.)

Paul Blustein was formerly the Tokyo correspondent for the Washington Post.