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Effect of Contaminated Soil on Food Chain Sparks Fears
Cesium absorption through roots may have long-term effect on farming
Six months after the nuclear meltdowns in Fukushima Prefecture, the public's awareness of the threat posed by radiation is entering a new phase: the realization that the biggest danger now and in the future is from contaminated soil.
The iodine-131 ejected into the sky by the Fukushima No. 1 power station disaster was quickly detected in vegetables and tap water — even as far away as Tokyo, 220 km south of the plant.
But contamination levels are now so low they are virtually undetectable, thanks to the short half-life of iodine-131 — eight days — and stepped up filtering by water companies.
But cesium is proving to be a tougher foe. The element's various isotopes have half-lives ranging from two to 30 years, generating concern about the food chain in Fukushima Prefecture, a predominantly agricultural region, as the elements wash fallout into the ground.
The root of the problem is, well — roots.
Cesium-134 and cesium-137 are viewed as potential health threats because vegetables can absorb the isotopes from the soil they're planted in.
"Until early spring, produce was contaminated (on the surface with radioactive materials) that the No. 1 plant discharged into the atmosphere. But now, the major route of contamination is through plant roots," said Kunikazu Noguchi, a radiation protection expert at Nihon University.
Whether absorption by plant roots can affect human health remains to be seen. Experts are warning that the region's soil and agricultural products will require close monitoring for many years.
At the moment, sampling data collected by the various prefectural governments indicate that no vegetables, except for those grown in Fukushima Prefecture, have been found to contain more than the government's provisional limit of 500 becquerels per kilogram since June.
Likewise, as of Sept. 7, samples of pork, chicken, milk and fruit had also tested within the provisional radiation limit, apart from Fukushima products and tea from Chiba, Kanagawa, Gunma, Tochigi, Saitama and Ibaraki prefectures.
In fact, the amount of radioactive materials in most of the food sampled has been steadily declining over the past few months, except for produce from Fukushima.
"The results of Fukushima's sampling tests show the amountof radioactive material contained in vegetables has dropped sharply in recent months, including those grown in areas with high radiation levels," Noguchi said.
"People shouldn't worry about it much (for the time being)," he said. "But mushrooms and other vegetables grown in contaminated forests are likely tocontain high levels of radioactive materials."
Now that soil in a wide area of eastern Japan has been contaminated with cesium, experts are calling for close monitoring of soil and produce.
The education ministry conducted soil surveys in June and July at 2,200 locations within 100 km of the crippled plant. At 34 locations in six municipalities in Fukushima Prefecture, including Minamisoma, Namie and Iitate, the data said cesium levels had exceeded 1.48 million becquerels per sq. meter — the same level that was used to define the exclusion zone around Chernobyl in 1986.
Yasuyuki Muramatsu, a radiochemistry professor at Gakushuin University, said that agricultural contamination will likely peak this year because cesium binds more strongly with minerals in soil as time passes, making it more difficult to be absorbed by plant roots.
"Data from the Chernobyl disaster show that radioactive cesium in soil tends to become fixed more strongly to clay minerals as time passes. So agricultural contamination will lessen next year," he said.
Muramatsu urged that special caution should be taken over products grown in soil rich in organic matter, such as in forested areas.
"If the soil is rich in organic matter, it makes (cesium) more easily transferable to plants. . . . Forest soil is rich in organic matter, so people should be careful," he said.
"This year, it's very important to conduct thorough surveys. The contamination will continue for a long time, so data collection is essential," Muramatsu said.
"We need to be prepared for the following years by recording data this year and studying the rate at which cesium in the soil is absorbed by each kind of produce," Muramatsu said.
In the meantime, the radioactivity itself will continue to weaken over the years. Cesium-134 has a half-life of 2 years and cesium-137 a half-life of 30 years, meaning the radiation they emit will drop by half in 2 years and 30 years.
The ratio of cesium-134 to cesium-137 in the Fukushima accident is estimated as 1-to-1, while the ratio during the 1986 Chernobyl disaster was 1-to-2. This indicates the radiation in Fukushima will weaken at a faster rate than at Chernobyl.
Between April and early August, the farm ministry tested soil at some 580 locations in six prefectures, including Fukushima, Tochigi and Gunma, to get a better picture of the full extent of contamination.
According to the results, 40 locations in Fukushima Prefecture had an intensity exceeding 5,000 becquerels per kilogram — the government's maximum limit for growing rice. Many municipalities within 30 km of the Fukushima No. 1 plant were banned from planting rice based on similar tests conducted in April.
In addition, the ministry has asked 17 prefectures in eastern Japan to conduct two-phase radiation tests on harvested rice.
So far, none of the tests performed on unmilled rice — including from Fukushima — exceeded the government's limit of 500 becquerels per kilogram.
Masanori Nonaka, an agriculture professor at Niigata University who specializes in soil science, said rice grown in contaminated areas is likely to be tainted, but to what extent is anyone's guess. White rice, however, may prove to be safe, Nonaka said. Because most of the radioactive material will adhere to the bran — the part of the husk left behind after hulling — about 60 percent of the cesium can be removed just by polishing it, he explained.
Other foods, such as marine produce, won't be as easy to handle, experts say. After the Chernobyl accident, for example, the radioactive contamination of fish peaked between 6 to 12 months after the disaster.
The Fisheries Agency, meanwhile, has asked nine prefectures on the Pacific coast to increase their sampling rates to prevent contaminated fish from landing in supermarkets.
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24 Comments so far
Show AllThe solution, we have observed. is a simple one: raise the acceptable limits.
"Whether absorption by plant roots can affect human health remains to be seen."
Right. No one knows if eating radioactive material is bad for you. It will take years of study to find out.
Reassuring to know sampling rates have to be increased in order to prevent contaminated fish from reaching market. All these figures being released, suppressed, or manipulated don't have a lot of credibility if I learned anything since this disaster. Glenn Greenwald's article yesterday, 'Orwell,' pretty much sums it up.
Ahh yasss. Nothing to worry about, just be patient.
The increase in miscarriages and still births in the coming years will just be "coincidence." The increase in cancers, the same.
A microscopic amount of these alpha and beta emitters, if it lodges in the lungs or the gut, will leave a tiny emitter bombarding a tiny amount of tissue. That can cause a cancer. Some of these isotopes have an affinity for certain types of tissue including bone.
It may take ten or twenty years for this to manifest into a malignant cancer. I am a nuclear veteran (Operation Redwing, Bikini Atoll, 1956) and was a frequent visitor to a website for nuclear veterans until the site finally went down. The deaths from various cancers was horrifying. Many families told me of the illness of their relative who had been at one of the test series, usually rather nasty cancers. Others wrote me of the birth defects and miscarriages that their families endured. There are not many of us left. So far, I am one of the lucky ones, but I still remember the horror as I became fatigued, had stomach pain, then my hair started coming out in clumps and my gums bled. I was almost nineteen then and doubted I would make twenty.
I'm still here, one of a rapidly diminishing number. You don't need a Hydrogen bomb to become poisoned. We've seen it at TMI, Chernobyl, a number of other, less publicized, accidents and now we are seeing it at Fukushima, and will for many years.
All of the nuclear industry's sugar pills will not make it any better. We breathe and eat. A microscopic amount needs only to be inhaled or ingested. It may or may not adhere to some cells, but if it does it will bombard said cells with low level radiation. The probability of a cancer developing is not 100%, but it is a lot higher than if the particle had not been inhaled or ingested.
So, we are looking at a global increase in cancers and birth defects, just as we have had after Chernobyl. DU turns up in atmospheric filters around the world, which means we have a strong possibility of ingesting a particle of that. It only has a half-life of around three-and-a-half billion years. But, since it blows holes in tanks and concrete walls, we continue to use it, and sell it.
Great post.
An old family friend was one of the first Americans ashore at Nagasaki just a few days after the bomb. The first thing he noticed was the fine dust that covered everything, including himself and all the other Marines.
At the time none of them knew much about the bomb and nothing at all about radiation. Like those of you at Bikini, they too were all told there was nothing to worry about.
What a pile of radioactive horseshit this article is! I see the Japan Times is happily carrying water for TEPCO.
Reading this happy happy news, you would hardly know there is an unprecedented 3 reactor meltdown/meltout in progress, as well as a destroyed fuel holding pool. The quantities of radioactive materials now being released into the air, ground, and oceans, exponentially dwarf Chernobyl's releases. Tepco has no idea how to contain this growing nightmare.
What I've learned from this nightmare is that the MSM in Japan is just as bought as the MSM in the U.S. and possibly even more corrupt. I didn't think that was possible, but how else to explain the total news blackout and manipulation in Japan about a catastrophic event that may yet render Tokyo uninhabitable and possibly destroy Japan?
Thanks for saying it straight out. Money talks ...bull shit walks. takes on a whole new meaning.
You are, of course, correct. Nothing "mainstream" in Japan can be "free" in the Western sense of the word.
The Japan Times isn't exactly bought however. Nor is it coerced like newspapers in dictatorships. It's more like a department in the public relations division of what used to be called Japan, Inc.
What we would call collusion is thought of as cooperation in Japan, and I understand traditionally journalists from "competing" newspapers and broadcasting companies hammer out a consensus so that all stories are tailored to fit an agreed-upon slant.
Virtually no news can come from Japanese news sources that isn't in someway the official line.
Advertisement: "Light up with this whole BRAN cereal from the Orient!" Get yours now...
Yes, it is easier and safer to see the emperor's new clothes as opposed to the truth that he is butt naked and ugly.
Sioux: I was thinking the same. Just how many people in the orient use rice bran oil in their cooking? Just makes for a double whammy.
According to E. Sternglass the dose response relationship describes a supralinear curve as opposed to the linear relationship our regulatory agencies tout . That is to say exposure to low level radiation is almost as bad as exposure to high levels. Once again, the U S will become the dumping ground for radioactive food as was the case after Chernobyl trashed eastern European farmlands. Radioactive preserves, cheeses, meats, wines were no longer consumed in aspiring second world countries, but were sold at 'bargain prices ' all across the U S . This time it will include lots of west coast products that we will be unable to export . Look for big jars of grape jelly at remarkable discounts. Also look for unusually large produce.
Ahh but the epidemiological effects of ingesting radioactivity are known. The VA has records on all the veterans exposed like minitrue and their families. The New York Academy of Sciences did a survey of the medical literature from Chernobyl and published their results, but there was concerted denial and and ignoring among the establishment, but the science was not disproved. The results--close to a million dead prematurely and 600,000,000 ill in the Northern Hemisphere. There are at least 2,600 genetic diseases that can be triggered by radioactivity. Today 25 years after Chernobyl only 1 in five children in Belarus has a normal IQ.
how many govts are now consumed in complete coverups such as TEPCOs info management with an openly complicit NEW japanese prime minister. An 8-day old environment ministers resigns for mentioning ghost town.
Tokyo region to become uninhabitable, N Japan and eastern pacific nuclear wastelands and no public comment on its ramification for the golbal food chain. We are in uncharted teritory and its security implications are far graver than any other political problem. Another quake could ignite this already bleak crisis. Is their any body which can manage the public interest
we are living in a futuristic nightmare... already.
And we don't even have the flying cars.
It's safe to assume that the executives at TEPCO are only eating imported food.
"Those are really big chickens"
Reminds me of a funny movie I saw back in the 70's. Wha da bunch a pigs we've all become!
...but...but...but...the MIT "expert" Josef Oehmen said there was nothing to worry about since the amount o fradiation released would not be any more than you get on a plane ride.
Whatever else may be true, one thing is certain: japan's export market for meat and produce is toast (for 30 years?)
Figure that into the cost of nuclear power.
Yeah ~~Jimbojangles~~... Don't you just love what some scienitsts say?___ I never realized when I rode on an airliner that I was in jeapordy of (inhaling) cesium-137.
I wonder if Japan's food exports are going to be toast? __ The US is the only country which imports contamintted food form the Chernobyl area. The major food mongols like Wal-Mart get it at bargain prices... Yummy yum.
What never fails to amaze me is scientists and writers speak of (eating) cesium 134 and 137 as a health hazard, but few ever talk about the health hazard of (inhaling) the microscopic, radioactive isotopes, which has to be far worse than eating any.
When eaten they normaly pass on through our digestive system and end up in the sewage treatment plants', or our spetic tanks, or in the woods and bushes.
When (inhaled) they end up in our liver, brain, bone marrow, or other body organs and radiate nearby body cells which can cause cancers to develop..It all depends upon how many are inhaled of course, one, or ten, or a hundred, or a thousand or more on what the odds and our chances are of cancers developing. The more the merrier.
There are an estimated five billion isotopes of cesium-137 in a cupfull. Wonder how many cupfulls arrive here from Fukushima and accumulate daily? They are (airborne) and easy to inhale... That is a well known fact which or EPA wizards and our Pro nukers don't wish to talk about.
Those deadly poisons arrive here via the Jet Stream. Those microscopic isotopes of poison don't just all lay in the soil... When the wind blows it picks up ground dust, pollens and other things, (like radioactive isoptopes) and blows them wherever the wind takes them.
Have I ever mentioned this before?
There you go again, confusing the issue with facts.
Wayne wrote:
'What never fails to amaze me is scientists and writers speak of (eating) cesium 134 and 137 as a health hazard, but few ever talk about the health hazard of (inhaling) the microscopic, radioactive isotopes, which has to be far worse than eating any.'
And for good reason. The hazards of inhaled radioactive cesium in mainland US are dwarfed by those of ingesting food containg the isotopes.'
'When eaten they normaly pass on through our digestive system and end up in the sewage treatment plants', or our spetic tanks, or in the woods and bushes.'
When (inhaled) they end up in our liver, brain, bone marrow, or other body organs and radiate nearby body cells which can cause cancers to develop..It all depends upon how many are inhaled of course, one, or ten, or a hundred, or a thousand or more on what the odds and our chances are of cancers developing. The more the merrier.'
What happens to Cs-134 and Cs-137 that leaves Fukushima? Since the metal is highly volatile, much of it becomes vapor, never to descend to Earth. Some of it (in either the solid or liquid phase) form tiny droplets or particles in the form of colloids, again, never to descend to Earth. Larger particles or droplets (aerosols) do indeed eventually fall to Earth or to water. Cesium adheres strongly to soil, where it is taken up by plants (which are eaten by animals), thereby entering the food chain. When ingested by humans, most of the cesium quickly enters the bloodstream, whence some of the isotope is distributed throughout the body, especially into muscle.
The element is eliminated from the body with a biological half-life of from 30 to 120 days, approximately. During its time in the body, the beta rays (a form of ionizing radiation) present a real health hazard.
The amount of radioactive cesium in the air breathed in mainland US may be too small to measure. And if it IS inhaled, it will likely then be exhaled. Although it CAN adhere to the alveoli of the lungs. And it CAN then enter the bloodstream. But dangers due to inhaled radiocesium pale compared to those of the ingested isotope.
John
~~John Lannetta~~ likely Also Known As,,, FRinston,,, Mark Abram,,, says once again that inhaling cesium 137 or other radioactive poisons is very unlikely and it is very unlikely those poisns are arriving here in the Northen American Hemisphere, US and Canada and beyond.
Johnny wrote,,, ("What happens to Cs-134 and Cs-137 that leaves Fukushima? Since the metal is highly volatile, much of it becomes vapor, never to descend to Earth.")... Whoooopie, we FINALLY now know exactly how to destroy radioactive isotopes.... All we have to do with radioactive wastes is burn them and let the isotopes enter the atmosphere and forget they ever existed.... Are you really that stupid John?
John also wrote, once again... (" The element is eliminated from the body with a biological half-life of from 30 to 120 days, approximately. During its time in the body, the beta rays (a form of ionizing radiation) present a real health hazard.")
That (biological half life) nonsense is an unproven theory and John knows it..Once lodged in a body organ it stays there radiating nearby bidy cells until the person dies.
It has been scientifically and medically proven that inhaling radioactive isotopes, cesium -137, DU, etc, will likely cause cancer... The isotopes are airborne and inhaling them is not at all uncommon and to do so is far worse than eating any. In the area of Fukushima inhaling them is very common. In fact most likely for all who are there.