2008 Paper by French Researchers Says There Is No Histological/Morphological Change in Rats' Hearts after Chronic Ingestion of Cesium-137

French researchers concluded in their paper published in 2008 that there was no histological and morphological change and no arrhythmia in rats' hearts after chronic ingestion of low levels of cesium-137, though they did observe cardiovascular system impairments.

The researchers were trying to determine whether chronic ingestion of cesium-137 caused cardiovascular system impairment observed in children and liquidators after the Chernobyl nuclear power plant accident.

The researchers' conclusion runs counter to the assertion by several researchers like Dr. Yury Bandazhevsky, former director of the Medical Institute in Gomel, Belarus, that cesium accumulates in hearts, causes heart arrhythmia and results in histological and morphological change. In fact, after Dr. Bandazhevsky made lecture tours in Japan earlier this year, it is widely believed as truism, at least among lay people (non-researcher).

From Cardiovascular Toxicology March 2008, Volume 8, Issue 1, pp 33-40, via Springer Link (emphasis is mine):

Chronic Contamination of Rats with 137Cesium Radionuclide: Impact on the Cardiovascular System (Yann Guéguen,Philippe Lestaevel,Line Grandcolas,Cédric Baudelin,Stéphane Grison, Jean-René Jourdain,Patrick Gourmelon,Maâmar Souidi)

Abstract:

Cardiovascular system impairment has been observed in children and in liquidators exposed to the Chernobyl nuclear power plant accident. No experimental studies of animals have analyzed whether these disorders might be attributed to chronic ingestion of low levels of cesium 137 (¹³⁷Cs). Biochemical, physiological, and molecular markers of the cardiovascular system were analyzed in rats exposed through drinking water to ¹³⁷Cs at a dose of 500 Bq kg⁻¹ (6500 Bq l⁻¹). Plasma concentrations of CK and CK-MB were higher (+52%, P < 0.05) in contaminated rats. No histological alteration of the heart was observed, but gene expression was modified in the atria. Specifically, levels of ACE (angiotensin converting enzyme) and BNP (brain natriuretic peptide) gene expression increased significantly (P < 0.05). ECG analysis did not disclose any arrhythmia except ST- and RT-segment shortening (−9% and −11%, respectively, P < 0.05) in rats exposed to ¹³⁷Cs. Mean blood pressure decreased (−10%, P < 0.05), and its circadian rhythm disappeared. Overall, chronic contamination by an extreme environmental dose of ¹³⁷Cs for 3 months did not result in cardiac morphological changes, but the cardiovascular system impairments we observed could develop into more significant changes in sensitive animals or after longer contamination.

(H/T Dr. Masahiro Kami)

Tweet

Cesium-137 in Sediment in Lake Biel in Switzerland, Attributed in Part to Mühleberg Nuke Plant Located Upstream

The article attributes cesium-137 to discharge from Mühleberg Nuclear Power Plant.

From AFP, via Yahoo Malaysia (7/14/2013):

'Radioactivity found in Swiss lake' near nuclear plant

Scientists have discovered a radioactive substance in sediment under a Swiss lake used for drinking water and situated near a nuclear plant, the Le Matin Dimanche weekly reported Sunday.

While scientists cited in the report stressed there was no danger to human health, the discovery raises concerns about safety practices and a lack of transparency at the Muehleberg nuclear plant in northwestern Switzerland.

The plant is believed to have caused a spike in cesium 137 found in the sediment of Lake Biel and dating back to 2000 through the discharge of contaminated waste water into the Aar river that feeds into the lake, about 20 kilometres (12 miles) downstream, the weekly reported.

Geologists from Geneva University happened upon the spike while working on an unrelated research project in 2010, and chemists in the northern canton of Basel recently verified the findings, it said.

The Muehleberg plant is permitted to discharge water with very low levels of radioactivity subject to strict controls several times a year, according to Le Matin Dimanche.

Politicians and environmentalists however expressed outrage Sunday that the plant and nuclear inspectors had provided no information about the higher levels of cesium 137 released more than a decade ago into a lake that provides 68 percent of the drinking water to the nearby town of Biel.

"No one ever told me that there were abnormally high concentrations in the lake," Hans Stoekli, who served as Biel mayor from 1990 to 2010, told the paper, insisting that in light of the use of the lake for drinking water "the plant should have alerted us even in the case of minimal risk."

Environmental group Greenpeace voiced dismay at the news, urging the public prosecutor in the canton of Bern, where Biel and the Muehleberg plant are located, to investigate.

The group, which has long called for the plant's closure, also questioned in a statement how the Swiss Federal Nuclear Safety Inspectorate could have either missed the higher radioactive levels or decided not to inform decision makers or the public about them.

The Muehleberg plant, which came online in 1972, is 17 kilometres (11 miles) west of the Swiss capital Bern.

In the wake of the 2011 Fukushima disaster in Japan, the Swiss parliament approved a phase-out for the country's five atomic power plants by 2034.

As the article does not talk in numbers, I looked for the paper and found it: "Human impact on the transport of terrigenous and anthropogenic elements to peri-alpine lakes (Switzerland) over the last decades", by Florian Thevenon, Stefanie B. Wirth, Marian Fujak, John Poté, Stéphanie Girardclos, Aquatic Science, July 2013 (open access at Springer.com). It turns out that a cesium-137 spike was not just one time, but three different occasions:

Abstract

Terrigenous (Sc, Fe, K, Mg, Al, Ti) and anthropogenic (Pb and Cu) element fluxes were measured in a new sediment core from Lake Biel (Switzerland) and in previously well-documented cores from two upstream lakes (Lake Brienz and Lake Thun). These three large peri-alpine lakes are connected by the Aare River, which is the main tributary to the High Rhine River. Major and trace element analysis of the sediment cores by inductively coupled plasma mass spectrometry (ICP-MS) shows that the site of Lake Brienz receives three times more terrigenous elements than the two other studied sites, given by the role of Lake Brienz as the first major sediment sink located in the foothills of the Alps. Overall, the terrigenous fluxes reconstructed at the three studied sites suggest that the construction of sediment-trapping reservoirs during the twentieth century noticeably decreased the riverine suspended sediment load at a regional scale. In fact, the extensive river damming that occurred in the upstream watershed catchment (between ca. 1930 and 1950 and up to 2,300 m a.s.l.) and that significantly modified seasonal suspended sediment loads and riverine water discharge patterns to downstream lakes noticeably diminished the long-range transport of (fine) terrigenous particles by the Aare River. Concerning the transport of anthropogenic pollutants, the lowest lead enrichment factors (EFs Pb) were measured in the upstream course of the Aare River at the site of Lake Brienz, whereas the metal pollution was highest in downstream Lake Biel, with the maximum values measured between 1940 and 1970 (EF Pb > 3). The following recorded regional reduction in aquatic Pb pollution started about 15 years before the actual introduction of unleaded gasoline in 1985. Furthermore, the radiometric dating of the sediment core from Lake Biel identifies three events of hydrological transport of artificial radionuclides released by the nuclear reactor of Mühleberg located at more than 15 km upstream of Lake Biel for the time period 1970–2000.

The researchers took the sediment core sample from Lake Biel and measured the radioactivity over several decades. The chart below, from the paper, shows the initial bump in cesium-137 in 1951, then a high peak in 1963, both from the fallout from atmospheric nuclear testing. After Mueleberg Nuclear Power Plant came on line in 1972, cesium-137 peaked in 1976, then in 1986 (Chernobyl fallout), and again in 2000.

According to the researchers, cesium contamination attributable to Muehleberg Nuke Plant occurred in mid 1970s, early 1980s, and 2000:

Additionally to the three 137Cs markers generally used for dating (1951, 1963 and 1986) European sediment records, the Lake Biel sediment core (BIE10-3) revealed two additional 137Cs activity peaks at 8.5 (41 Bq/kg) and 30.5 cm core depth (94 Bq/kg) (Fig. 2). On the basis of the 210Pb age model, these peaks are dated to 2000 and 1975. The peak dated to 1975 has been reported in a previous study and detected in several Lake Biel sediment cores, of which the nearest is only 300 m away from our site (Albrecht et al. 1998). This increased 137Cs activity was caused by higher radionuclide discharges of the upstream Mühleberg NPP due to the use of low-quality fuel rods between 1976 and 1978 (Albrecht et al. 1998). In addition, a small 60Co activity peak detected at 22.5 cm core depth is dated to 1984 on the basis of our 210Pb activity age model (Fig. 2). Albrecht et al. (1998) suggested that this peak was related to higher wastewater discharges from the Mühleberg NPP documented in August of 1982. The age difference of 1–2 years between the age model and the date of the known nuclear events lies within the error range of our age model (see next paragraph). Our results therefore confirm the previous identification of increased radionuclide discharge by the Mühleberg NPP in 1976 (137Cs) and 1982 (60Co). However, regarding the 1982 event, our data is not as definite as Albrecht et al. (1998, 1999) because 60Co, which was the only released radionuclide during this event, shows at present only slightly elevated activity in our Lake Biel record.

In the upper part of our Lake Biel sediment core, a small 137Cs activity peak dated to 2000 is for the first time revealed by this study (Fig. 1). The 60Co as well as the 210Pb in excess (obtained after subtracting the 226Ra activity to the total 210Pb activity) profiles demonstrate that this 137Cs activity peak was not caused by other processes, such as reworking of sediment containing Chernobyl-linked activity or changes in sedimentation rates which would appear in the 210Pb in excess profile. Therefore, this 137Cs activity peak that is not accompanied by a coeval 60Co peak can be explained by two possible causes: (1) only 137Cs radionuclides were released to the environment, or (2) the 137Cs was better scavenged by the minerogenic fraction than 60Co. Indeed, only 30 to 55 % of the discharged 60Co is transferred to Lake Biel sediments and the scavenging efficiency of 60Co is higher during the winter period than during summer, in spite of higher particle fluxes during summer (Albrecht et al. 1999). Thus, the found moderate 137Cs activity peak likely points to an additional and so far undetected release of liquid radionuclides from the Mühleberg NPP to the Aare River in the year 2000 ± 2. This discharge event could coincide with an event reported at the Mühleberg NPP on the 6th of June 1998, when an accidental opening of a steam-relief valve led to an emergency shutdown of the reactor (Prêtre 1999). Yet, the Swiss government monitors radionuclide activity in the air and water near the Mühleberg NPP, but registered values for 1998 are similar to those of previous years and lie all below 3 % of the legal limit (Prêtre 1999).

Tweet

Cesium-137 Dispersion Simulation in the Pacific Ocean, 3/21/2011 - 1/27/2012

The radioactivity dispersion simulation JCOPE (Japan Coastal Ocean Predictability Experiment) by JAMSTEC (Japan Agency for Marine-Earth Science and Technology), showing cesium-137 dispersion in the Pacific Ocean from March 21, 2011 to January 27, 2012.

March 21, 2011 was when the high levels of radioactive materials from the seawater near the plant were first detected.

Screenshots from their JCOPE page with the simulation animation (1/30/2012). Click for bigger view:

Tweet

Cesium-137 Deposition Simulation Shows Extensive Ocean Contamination Even in Japan Sea

I wrote on Monday November 14 about the paper by the international team of scientists on cesium-137 deposition simulation after the Fukushima I Nuclear Power Plant accident, from March 20 to April 19.

In the English paper that I linked, there was a map of cesium-137 deposition simulation in much wider area of Japan, which I showed in the post.

But then, in the press release by Nagoya University (one of the scientists is from this university), I realized I should have linked the different map of cesium-137 deposition simulation on land and on the ocean. A whole lot of radioactive materials may have fallen on the ocean, the Pacific Ocean AND the Japan Sea. (Remember, this is a simulation map, not the actual measurement.)

Looking at the map, I don't think I want to eat anything from the Pacific Ocean. Or the Japan Sea. Abalone fishing just started in Iwate Prefecture.

By the way, the paper and the researchers were criticized heavily on Twitter a couple of days ago (it still continues) from other researchers in Japan. Their beef was that the researchers of the paper withheld this information from the public when it could have made the difference in determining the government policy or in alerting more people on the possibility of much wider radiation contamination. Instead, the researchers waited for the peer review in the very prestigious scientific venue (the National Academy of Sciences of the United States) to be finished and the paper published. Some say the researchers had the temerity to say in their Nagoya University press release on November 15, "We request that the information in the paper not be used to spread a new set of "baseless rumors" [on the contamination]."

Well, as we have seen, they are not alone. There have been a lot of Japanese researchers who have done what they just did, announcing what could have been the vital information after their papers got accepted by foreign peer-reviewed magazines. I personally know one, whose radiation survey result in locations in Fukushima might have made a significant difference. But the researcher is still sitting on the data (though he was careless enough to put it on his website for a long time), because his paper is being peer-reviewed.

But then there are researchers like Professor Yukio Hayakawa of Gunma University, who released the radiation contour map he created soon after the accident, to much ridicule from the establishment initially. And Professor Bin Mori of Tokyo University, who published his world-first discovery of bio-concentration of radioactive silver in spider on his personal blog, and allowed me to spread the information both in Japanese and in English so that more people know about it as soon as possible.

Well, Professors Hayakawa and Mori have the professorship, and these researchers do not. Still it is too bad that they had to put their careers before the welfare of the population in Japan.

Tweet

Yomiuri: Cesium in Body Will Halve in 1.5 Years in Wild Animals Even If They Eat Contaminated Food Everyday

Yomiuri Shinbun may have made a fool of itself by summarizing the finding by a university researcher regarding the biological half-life of radioactive cesium in a very exaggerated (and inaccurate) way.

If you read the article, it's rather embarrassingly clear that "wild animals" are lab mice, and "eating contaminated food everyday" is drinking cesium-laced water only once. It is possible that the researcher's paper made a connection between a mouse and a wild animal, and drinking water once and eating contaminated food every day, and Yomiuri Shinbun, in its eagerness to bring the good tidings to the general public in Japan, omitted the connection in the article.

Oh well. Many of my Japanese twitter readers who read the article are saying, "What can you expect from a pro-nuke newspaper like Yomiuri?" or "Gomiuri (garbage seller)?"

From Yomiuri Shinbun (11/18/2011):

東京電力福島第一原発事故直後に野生動物に大量に取り込まれた放射性セシウム１３７の量は、動物が原発周辺の食物を摂取していても約１年半ごとに半減し、最初の５年間で８分の１以下になる可能性が高いことを大阪大学の中島裕夫助教が突き止めた。

Hiroo Nakajima of Osaka University has found that there is a high possibility that a large amount of radioactive cesium-137 ingested by wild animals right after the Fukushima I Nuclear Power Plant accident may halve every 1.5 years, falling to one-eighths after the first 5 years even if the animals keep eating the food around the nuclear power plant.

原発周辺地域の野生動物や住民の内部被曝(ひばく)の状況などを知る手がかりになるもので、１７日、神戸市で開かれている日本放射線影響学会で発表した。

It will provide a clue to the internal radiation exposure of wild animals and people in the areas near the plant. His research was published in the meeting of the Japan Radiation Research Society in Kobe City on November 17.

中島助教は、マウスに半減期が約３０年のセシウム１３７を含んだ水（体重１グラム当たり１キロ・ベクレル＝１匹当たり２８キロ・ベクレル）を一回だけ飲ませた後、時間経過とともに体内に残る量を調べた。

Nakajima fed mice with water with cesium-137 whose half life is about 30 years (1 kilo-becquerel/1 gram of live weight, or 28 kilo-becquerels per mouse) once, and studied the amount of cesium remaining in the body over time.

心臓や腎臓など大半の臓器では、摂取後すぐにピークを迎えたが、１週間後には２５分の１以下、２週間後には１２０分の１以下になった。

In most organs such as heart and kidney, the amount of cesium peaked right after ingesting the water. However, it dropped to one-25th in one week, and to one-120th in 2 weeks.

So?

These wild animals (eh... mice) are likely to have been eating contaminated food and drinking contaminated water ever since March 11. So did people, like villagers in Iitate-mura or town folks in Namie-machi, for quite some time after the March 11 accident. They ate the vegetables they grew, and drank water from their wells, on assurance from the experts like Dr. Yamashita.

Here's the ICRP's chart, showing how the one-time episodic intake of 1000 becquerels of radioactive cesium is handled by the body, compared to the continuous, daily intake of low-level (10 becquerels and 1 becquerel) radioactive cesium (from ICRP publication 111, page 21):

(The researcher could have just put up this chart for his presentation, instead of feeding lab mice with cesium water.)

Tweet

Now They Tell Us: Cesium-137 Soil Deposition May Be Much Wider Than Thought, Hokkaido and Western Japan May Have "Hot Spots"

Not the news that weary radiation-vigilant residents of Japan (including Tokyo Brown Tabby) wanted to hear.

But according to a new research paper by the international team of scientists to be published on the electronic version of the Proceedings of the National Academy of Sciences of the United States of America (PNAS), cesium-137 (half life 30 years) may have deposited in the soil in much wider areas including Hokkaido, Chubu, Chugoku, Shikoku in one month starting March 20. The cesium deposition in these regions is considered to be in much lower concentration than in Tohoku or Kanto, but the researchers say there may be radiation "hot spots" in these regions.

It's no surprise to anyone who used to look at the dispersion simulations by Austria's ZAMG, Germany's DWD and Norway's NILU in the early days of the nuclear crisis in March, April and May. I remember seeing large plumes engulfing Hokkaido a number of times, and occasional small plumes swiping Shikoku.

From Jiji Tsushin News (11/15/2011; links added):

東京電力福島第1原発事故で放出された放射性物質のうち、半減期が約30年と長いセシウム137が、3月20日からの1カ月間に中部や中国、四国地方の山 岳地帯や北海道の土壌に沈着した可能性があることが分かった。米大学宇宙研究協会（USRA）や名古屋大、東京大などの国際チームが14日までに行ったシ ミュレーションの結果で、米科学アカデミー紀要電子版に発表される。

Of radioactive materials released from the Fukushima I Nuclear Power Plant accident, cesium-137, whose half life is 30 years, may have deposited in the soil in the mountains in Chubu and Shikoku regions, and Hokkaido, in a month starting March 20. It is a conclusion from the simulation done by the international team of scientists including those from the USRA (Universities Space Research Association), Nagoya University, and Tokyo University. Their paper will be published in the electronic version of the Proceedings of the National Academy of Sciences of the United States of America.

　これらの地域の大半は人体に影響を及ぼしたり、除染が必要だったりする汚染濃度ではないと推定される。ただ、局所的に濃度が高いホットスポットが存在する可能性があり、詳細な調査が必要という。

It is assumed that most of these areas do not have the level of contamination that may affect the health or may require decontamination. However, there may be "hot spots" with locally high radiation, and a detailed investigation may be necessary, according to the scientists.

　USRAの安成哲平客員研究員や名大の安成哲三教授、東大の早野龍五教授らは、ノルウェーで開発された地球全体の大気輸送モデル（20キロ四方単位）とヨーロッパ中期予報センターの気象データ、文部科学省の降下物観測データを組み合わせシミュレーションした。

Teppei Yasunari of USRA, Tetsuzo Yasunari of Nagoya University, and Ryugo Hayano of Tokyo University combined the global atmospheric transfer model (20-kilometer grid) developed in Norway, the meteorological data from European Centre for Medium-Range Weather Forecasts (ECMWF) [in Redding, UK] and radiation fallout measurement data from Japan's Ministry of Education and Science to do the simulation.

　その結果、日本列島へのセシウム137沈着量は1カ月間で1000テラ（テラは1兆）ベクレル以上と推定された。福島県を中心に東北、関東の太平洋側の 沈着量が多いのは文科省の航空機モニタリング結果などと一致したが、中部、中国、四国の山岳地帯や北海道でも、低気圧が通過した際に同原発からセシウム 137の微粒子を含む風が流入し、雨で沈着した可能性が示された。　

According to their simulation, the cesium-137 deposition in Japan was estimated to be more than 1,000 terabecquerels in one month [starting March 20]. The simulation matched the result of the aerial survey by the Ministry of Education that showed the Pacific Ocean side of Tohoku and Kanto had a larger amount of cesium deposition. However, the simulation also shows that when the low pressures passed over the mountain areas in Chubu, Chugoku and Shikoku regions and in Hokkaido, wind that contained cesium-137 particles from Fukushima I Nuclear Power Plant may have blown and the particles may have fallen with the rain and deposited in the soil.

The paper is here: http://www.pnas.org/content/early/2011/11/11/1112058108.full.pdf

From the "Discussion" section of the paper (page 4, left column)

...we expect the true soil contamination across Japan to be considerably more variable than in our estimate. Even in regions where we find relatively low soil contamination levels, hot spots with high concentrations (e.g., due to convective rain fall, orographic enhancement of rainfall, or fine-grain soil flow by rainwater on the ground) may be possible. In contrast, relatively clean patches may also be present in areas with high overall contamination levels.

Supplementary information and data: http://www.pnas.org/content/suppl/2011/11/14/1112058108.DCSupplemental/pnas.1112058108_SI.pdf

From Page 5 of the supplementary data above, "Estimated Cs137 Concentration in Soil" (screen shot from a movie)

"Movie S4. Estimated 137Cs concentration range in soil using DRT of 0.001 and conversion coefficient (CC) of 38, 53, and 68 kgm−2 over Japan. CCs of 38, 53, and 68 kgm−2 correspond to −1σ, mean value, and þ1σ in Fig. S5, respectively. Outputs 0.2° × 0.2° were interpolated into finer resolution using cubic interpolation. The Merged IBCAO/ETOPO5 Global Topographic Data Product (1) was used to mask out ocean area below 0 m above sea level (a.s.l.)."

The movie can be seen here.

Tweet

Nature: New Study Shows Fukushima Fallout Much Larger Than Japanese Government Estimate

The amount of cesium-137 is more than twice the official number, and the amount of xenon-133 55% more, according to a new study using a larger data set, says Nature.

The study claims the amount of cesium-137 from Fukushima is half of that from Chernobyl, and the amount of xenon-133 from Fukushima far exceeds Chernobyl.

As the reason why the Japanese government numbers were low: the Japanese government probably only accounted for the radioactive fallout within Japan. So the large amount that went over the Pacific Ocean, reaching North America and Europe was never considered by the Japanese government.

The new study also claims that the Reactor 4 Spent Fuel Pool emitted a large amount of cesium-137.

From Nature News (10/25/2011):

Fallout forensics hike radiation toll: Global data on Fukushima challenge Japanese estimates. (Geoff Brumfiel)

The disaster at the Fukushima Daiichi nuclear plant in March released far more radiation than the Japanese government has claimed. So concludes a study that combines radioactivity data from across the globe to estimate the scale and fate of emissions from the shattered plant.

The study also suggests that, contrary to government claims, pools used to store spent nuclear fuel played a significant part in the release of the long-lived environmental contaminant caesium-137, which could have been prevented by prompt action. The analysis has been posted online for open peer review by the journal Atmospheric Chemistry and Physics.

Andreas Stohl, an atmospheric scientist with the Norwegian Institute for Air Research in Kjeller, who led the research, believes that the analysis is the most comprehensive effort yet to understand how much radiation was released from Fukushima Daiichi. "It's a very valuable contribution," says Lars-Erik De Geer, an atmospheric modeller with the Swedish Defense Research Agency in Stockholm, who was not involved with the study.

The reconstruction relies on data from dozens of radiation monitoring stations in Japan and around the world. Many are part of a global network to watch for tests of nuclear weapons that is run by the Comprehensive Nuclear-Test-Ban Treaty Organization in Vienna. The scientists added data from independent stations in Canada, Japan and Europe, and then combined those with large European and American caches of global meteorological data.

...The latest report from the Japanese government, published in June, says that the plant released 1.5 × 10^16  bequerels of caesium-137, an isotope with a 30-year half-life that is responsible for most of the long-term contamination from the plant. A far larger amount of xenon-133, 1.1 × 10^19 Bq, was released, according to official government estimates.

The new study challenges those numbers. On the basis of its reconstructions, the team claims that the accident released around 1.7 × 10^19 Bq of xenon-133, greater than the estimated total radioactive release of 1.4 × 10^19  Bq from Chernobyl. The fact that three reactors exploded in the Fukushima accident accounts for the huge xenon tally, says De Geer.

Xenon-133 does not pose serious health risks because it is not absorbed by the body or the environment. Caesium-137 fallout, however, is a much greater concern because it will linger in the environment for decades. The new model shows that Fukushima released 3.5 × 10^16  Bq caesium-137, roughly twice the official government figure, and half the release from Chernobyl. The higher number is obviously worrying, says De Geer, although ongoing ground surveys are the only way to truly establish the public-health risk.

Stohl believes that the discrepancy between the team's results and those of the Japanese government can be partly explained by the larger data set used. Japanese estimates rely primarily on data from monitoring posts inside Japan, which never recorded the large quantities of radioactivity that blew out over the Pacific Ocean, and eventually reached North America and Europe. "Taking account of the radiation that has drifted out to the Pacific is essential for getting a real picture of the size and character of the accident," says Tomoya Yamauchi, a radiation physicist at Kobe University who has been measuring radioisotope contamination in soil around Fukushima.

Stohl adds that he is sympathetic to the Japanese teams responsible for the official estimate. "They wanted to get something out quickly," he says. The differences between the two studies may seem large, notes Yukio Hayakawa, a volcanologist at Gunma University who has also modelled the accident, but uncertainties in the models mean that the estimates are actually quite similar.

The new analysis also claims that the spent fuel being stored in the unit 4 pool emitted copious quantities of caesium-137. Japanese officials have maintained that virtually no radioactivity leaked from the pool. Yet Stohl's model clearly shows that dousing the pool with water caused the plant's caesium-137 emissions to drop markedly (see 'Radiation crisis'). The finding implies that much of the fallout could have been prevented by flooding the pool earlier.

(The article continues.)

Tweet

Amount of Radioactive Cesium in Urine Increased in a Boy Who Remained in Fukushima

From Jiji Tsushin (9/7/2011):

市民団体「福島老朽原発を考える会」などは７日、尿検査で放射性セシウムが検出された福島市などの子ども１０人を２カ月後に再調査したところ、他県に避難しなかった１人で数値が減少せず、微増したと発表した。

A citizen's group (福島老朽原発を考える会) announced the result of the second testing of the 10 children in Fukushima City and other locations whose urine had been tested 2 months earlier. In one child who did not evacuate from Fukushima, the amount of radioactive cesium didn't decrease but increased slightly.

　同会などは５月、フランスの放射線計測機関に依頼して６～１６歳の男女１０人の尿を検査し、全員からセシウムを検出。７月末に再調査した結果、県外に避難した９人は数値が下がったり、検出されなくなったりしたが、福島市に残った１６歳の少年はセシウム１３７が１リットル当たり０．７８ベクレルから同０．８７ベクレルに増えたという。

In May, the group asked a French laboratory to test the urine samples from 10 children from 6 to 16 years old. Radioactive cesium was detected from all samples. In the second test conducted at the end of July, the amount was lower, or in some cases not detected, in 9 children who evacuated from Fukushima Prefecture. However, from the urine sample of a 16-year-old boy who remained in Fukushima City, cesium-137 increased from 0.78 becquerels/liter in May to 0.87 becquerels/liter.

France's ACRO, who did the testing, has more details and harsh words for the Japanese government (emphasis is original):

Comments :

At the request of Japanese citizens, ACRO analyzed the urine of 18 Japanese children from the prefecture of Fukushima and from Tokyo and its surroundings.

All the 15 children from Fukushima have or had their urine contaminated with radioactive fallout from the nuclear accident located approximately 60 km away. This means that children themselves have been or are contaminated. However, we did not detect any contamination in the urine of the three children from Tokyo and surroundings.

While the tests performed by the Japanese authorities give about one child from Fukushima out two that is contaminated, we get 100%. This reflects the fact that the official measurements are not accurate enough and did not detect all contaminations.

The first 10 children are the same as in our previous measurement campaign (results released June 30). 9 of them have left the province of Fukushima since. Only one remained (U2).
U6 child was evacuated in end of March. U3 and U4 children were evacuated in the end of May. 3 left late June, early July and three others at the beginning of the school holidays from July 22.

Finally, five new children live nearby Fukushima-city. One of them was evacuated in the middle of May (U14).

U11 and U12 attend the same high school where they frequently practice sports on the same playground. The difference in the contamination could be due to food.

More than four months after the massive discharges of radioactivity into the environment, all children still in Fukushima at the time of urine sampling were contaminated, although their parents do their best to reduce this contamination. Evacuation is a way to reduce contamination. Variations in internal contamination between different children might be due to food.

It is important to conduct an accurate, systematic and regular monitoring of internal contamination of children from Fukushima. Families must have access to the measurement of radioactivity to help them reduce this contamination.

(H/T 44de256)

Tweet

Simulation Map of Cesium-137 Deposition Across the Pacific by CEREA Shows Contamination in US Greater Than That of Western Japan

France's CEREA has the simulation map of ground deposition of cesium-137 from the Fukushima I Nuclear Power Plant accident on its "Fukushima" page. It not only shows Japan but also the entire northern Pacific Rim, from Russian Siberia to Alaska to the West Coast of the US to the entire US.

According to the map, the US, particularly the West Coast and particularly California, may be more contaminated with radioactive cesium than the western half of Japan or Hokkaido. It looks more contaminated than South Korea or China. Canada doesn't look too well either, particularly along the border with US on the western half.

From CEREA's Fukushima page:

Atmospheric dispersion of radionuclides from the Fukushima-Daichii nuclear power plant

CEREA, joint laboratory École des Ponts ParisTech and EdF R&D
Victor Winiarek, Marc Bocquet, Yelva Roustan, Camille Birman, Pierre Tran

Map of ground deposition of caesium-137 for the Fukushima-Daichii accident.

The simulation was performed with a specific version of the numerical atmospheric chemistry and transport model Polyphemus/Polair3D. The parametrisations used for the transport and physical removal of the radionuclides are described in [1,2,3,4].

The magnitude of the deposition field is uncertain and the simulated values of deposited radionuclides could be significantly different from the actual deposition. In particular, the source term remains uncertain. Therefore, these results should be seen as preliminary and they are likely to be revised as new information become available to better constrain the source term and when radionuclides data can be used to evaluate the model simulation results.

The page also has the animated simulation of cesium-137 dispersion from March 11 to April 6, 2011. If the Japanese think they are the only ones who have the radiation and radioactive fallout from the accident, they are very much mistaken, if the simulation is accurate. (Meteorological institutes and bureaus in Austria, Germany, and Norway all had similar simulation maps.)

Radioactive materials spewed out of Fukushima I Nuke Plant went up and away on the jet stream, reaching the other side of the Pacific. When the fallout from explosions (March 14, 15) reached the US West Coast, it came with an unusually heavy rainfall in California.

CEREA's description of the animation (if the animation doesn't work, or if you want to see the bigger one, go to CEREA's page):

Movie of the Fukushima-Daichii activity in the air (caesium-137, ground level)

The simulation was performed with a specific version of the numerical atmospheric chemistry and transport model Polyphemus/Polair3D. The parametrisations used for the transport and physical removal of the radionuclides are described in [1,2,3,4].

The magnitude of activity concentration field is uncertain and could be significantly different from the actual one. In particular, the source term remains uncertain. Therefore, these results should be seen as preliminary and they are likely to be revised as new information become available to better constrain the source term and when radionuclides data can be used to evaluate the model simulation results.

(Go to their page to see the references.)

Tweet

Soil Contamination in 34 Locations in Fukushima Exceeds Chernobyl Confiscation/Closed Zone Level

In one location, the contamination level is more than 10 times the Chernobyl level.

What a surprise. Now that PM Kan is out, the government dribbles out the information that it withheld as it de-emphasized and even attacked the reports of high soil contamination as measured by private entities including citizens' groups.

The most contaminated location found so far is Okuma-machi, where Fukushima I Nuke Plant is located: 29,460,000 becquerels per square meter with cesium-134 and cesium-137 combined, 15,450,000 becquerels per square meter if only cesium-137 is counted.

The confiscated/closed zone after the Chernobyl accident is set in locations whose cesium-137 level in soil exceeds 1,480,000 becquerels per square meter. The level of cesium-137 in the location in Okuma-machi is 10 times that of the Chernobyl confiscated/closed zone.

From Yomiuri Shinbun (3:05AM JST 8/30/2011):

東京電力福島第一原子力発電所事故で拡散した放射性物質による土壌汚染の状態を調べた地図がまとまり、２９日に開かれた文部科学省の検討会で報告された。

The soil contamination as the result of the Fukushima I Nuclear Power Plant accident was reported on the August 29 meeting at the Ministry of Education and Science.

　立ち入りが制限されている警戒区域や計画的避難区域で、チェルノブイリ原発事故での強制移住基準（１平方メートル当たりの放射性セシウム１３７が１４８万ベクレル）を超える汚染濃度が測定されたのは、６市町村３４地点に上った。住民の被曝(ひばく)線量などを把握するのが狙い。菅首相が２７日、「長期間にわたり住民の居住が困難になる地域が生じる」との見通しを示したが、それを裏付けた。

The survey found 34 locations in 6 municipalities exceeding the level of the confiscation/closed zone of the Chernobyl accident (1,480,000 becquerels/square meter of cesium-137 in soil). The purpose of the survey was to understand the radiation exposure of the residents. Prime Minister Kan said on August 27 that there might be locations where the residents wouldn't be able to return for a long time. The survey data validates the prime minister's comment.

　測定結果によると、６月１４日時点で、セシウム１３７の濃度が最も高かったのは、警戒区域内にある福島県大熊町の１平方メートル当たり約１５４５万ベクレル。セシウム１３４と合わせると、同約２９４６万ベクレルとなった。

According to the survey, the highest cesium-137 concentration in soil as of June 14 was in Okuma-machi in Fukushima Prefecture, within the no-entry evacuation zone, at 15,450,000 becquerels/square meter. If combined with cesium-134, the radioactive cesium concentration was 29,460,000 becquerels/square meter.

　同３００万ベクレル超となったのは、セシウム１３７で同町、双葉町、浪江町、富岡町の計１６地点に上った。高い濃度の地点は、原発から北西方向に延びており、チェルノブイリ事故の強制移住基準を超える地点があった自治体は、飯舘村、南相馬市を加えた計６市町村だった。同省は約２２００地点の土壌を測定した。

Total 16 location in 4 municipalities (Okuma-machi, Futaba-machi, Namie-machi, Tomioka-machi) exceeded 3,000,000 becquerels/square meter in cesium-137 concentration. The area with the high cesium-137 concentration extends northwest from the nuclear power plant. In total, 6 municipalities including Iitate-mura and Minami Soma City had the locations that exceeded the Chernobyl confiscation/closed zone level of cesium-137. The Ministry measured the soil samples from about 2,200 locations.

Here's the map by Asahi Shinbun, including the locations with cesium-137 concentration of less than 1 million becquerels/square meter.

Tweet

13% of Radioactive Iodine, 22% of Radioactive Cesium from Fukushima I Nuke Plant Landed in Central/Northern Japan

The rest was either blown off to the ocean or landed somewhere else in Japan.

Researchers at the National Institute of Environmental Studies (NIES) had their paper published in the electronic version of "Geophysical Research Letters" published by the American Geophysical Union on August 11, and they announced the result of their research in Japan on August 25.

The paper was submitted on June 27, and they kept quiet until the research was published. The researchers at this government institute therefore knew all along how bad the contamination was all over southern Tohoku and all of Kanto and part of Chubu.

Abstract of the paper titled "Atmospheric behavior, deposition, and budget of radioactive materials from the Fukushima Daiichi nuclear power plant in March 2011" by Yu Morino, Toshimasa Ohara,* and Masato Nishizawa, Regional Environment Research Center, National Institute for Environmental Studies, 16-2, Onogawa, Tsukuba, Ibaraki, 305-8506, Japan:

To understand the atmospheric behavior of radioactive materials emitted from theFukushima Daiichi nuclear power plant after the nuclear accident that accompanied the great Tohoku earthquake and tsunami on 11 March 2011, we simulated the transport and deposition of iodine-131 and cesium-137 using a chemical transport model. The model roughly reproduced the observed temporal and spatial variations of deposition rates over 15 Japanese prefectures (60–400 km from the plant), including Tokyo, although there were some discrepancies between the simulated and observed rates. These discrepancies were likely due to uncertainties in the simulation of emission, transport, and deposition processes in the model. A budget analysis indicated that approximately 13% of iodine-131 and 22% of cesium-137 were deposited over land in Japan, and the rest was deposited over the ocean or transported out of the model domain (700 × 700 km2). Radioactivity budgets are sensitive to temporal emission patterns. Accurate estimation of emissions to the air is important for estimation of the atmospheric behavior of radionuclides and their subsequent behavior in land water, soil, vegetation, and the ocean.

No other nuclides are discussed in the paper. But just for these two, if you look at the deposition and concentration simulation maps below, you see that at least half Fukushima Prefecture is "red", not just along the coast, which means the highest deposition of both iodine-131 and cesium-137 in high concentration. Southern Miyagi is just as bad as Fukushima , so is part of Ibaraki and Tochigi.

From their paper (page 19) - top row is the cumulative surface deposition amount of iodine-131 and cesium-137 from March 11 to 29; the bottom row is the average concentration of iodine-131 and cesium-137, again from March 11 to 29:

Now that their paper has been safely published, I wonder if these researchers will speak up (or the government will allow them to speak up) on the subject of radioactive contamination in much of Tohoku and Kanto. I doubt it, but I hope so. I wish they had spoken up much earlier, but I understand that having their paper published by a prestigious foreign academic society is very important for a scientific researcher.

(While I do understand the restriction on the researchers like not allowing them to publish the data before the paper is peer-reviewed and published, but I do wonder if the academic society or the magazine would have given them some sort of waiver. The paper was not about Chernobyl cesium deposition 25 years after people were evacuated from the area; it is about an on-going disaster where many people's lives may be at stake. Oh well.)

Tweet