Long Shadow of Chernobyl: 224 Bq/kg of Cesium-137 in the Ashes from Burning Wood Pellets Made from Trees in Shikoku

And of atmospheric testing of nuclear weapons by world nuclear powers, which did not stop until 1980 (China).

One of my twitter followers lives in southwestern Japan. A while ago he sent me the result of the test he had it done with the ashes from burning wood pellets in his stove this winter. The lab test, using the germanium semiconductor detector, found 223.8 Bq/kg of cesium-137.

He was upset, thinking it is from Fukushima I Nuclear Power Plant, until I pointed out to him that there was no cesium-134 found. The cesium in the ashes is most likely from the fallout from atmospheric testing, and the Chernobyl accident in 1986.

He burned 600kg of wood pellets made from cedar trees in Ehime Prefecture in Shikoku Island in southwestern Japan. According to the pellet manufacturer, the concentration factor was about 375, and radioactive cesium (Cs-137) in the pellets was estimated to be about 0.59 Bq/kg.

He said he will "entomb" the ashes with concrete and bury.

The chart plotting the historical monthly fallout in entire Shikoku (4 prefectures, as they didn't start measuring the fallout in Ehime until 1977) shows the spike from the Chernobyl accident was less than that of the atmospheric testing, and larger than that from the Fukushima accident. (The chart was created from data at Japan Chemical Analysis Center. Y-axis in log scale.)

In 2012 he tested the ashes from burning the wood pellets from a different company, and to his great dismay the test found 1,000 Bq/kg of radioactive cesium (Cs-137) in the ashes. He had already spread some of those ashes on his home garden. Those pellets, it turned out, were made from trees from Europe (Sweden, Finland, Germany, Austria) that the manufacturer had started to purchase in 1994 . That manufacturer told him that it had never ever occurred to them that the trees were contaminated from the Chernobyl accident, and there was no regulation on importing. The manufacturer told him that they chose European trees because they were cheap, and supply was steady.

April 26 marks the 27th anniversary of the Chernobyl Nuclear Plant accident.

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#Radioactive Strontium Was Detected in Monthly Fallout As Late As November Last Year in Chiba, Ibaraki, Ministry of Education's Data Shows

But the Ministry of Education (MEXT) doesn't think the strontium-90 fallout after May last year was of Fukushima origin.

Following up on the post about strontium-90 fallout last year that MEXT (Ministry of Education and Science) announced on July 24 this year, I found some interesting data in the Japan Chemical Analysis Center where I created the chart plotting the Sr-90 fallout for the past 50 years or so in Japan (reproduced here).

The 2011 monthly fallout data for strontium-90 at the Japan Chemical Analysis Center is easier to see than the MEXT PDF file pages (they are the same data). As I was browsing through the search result, I started to wonder:

When was the last month that strontium-90 was detected in the fallout for these ten prefectures?

So here it is, from the search result at the Japan Chemical Analysis Center's website, the last date when strontium-90 was detected in the monthly fallout in the cities/prefectures in Tohoku and Kanto in 2011:

Aomori City, Aomori: March 31
Morioka City, Iwate: September 10
Akita City, Akita: July 1
Yamagata City, Yamagata: July 1
Hitachinaka City, Ibaraki: November 1
Utsunomiya City, Tochigi: August 1
Maebashi City, Gunma: June 1
Saitama City (Sakura-ku), Saitama: August 1
Ichihara City, Chiba: November 1
Chiba City (Inage-ku), Chiba: November 1
Shinjuku-ku, Tokyo: August 1
Chigasaki City, Kanagawa: June 30

Of these results, MEXT doesn't seem to think the detection in Aomori had anything to do with the Fukushima nuclear accident, as the prefecture is excluded from the list by MEXT in the press release (see my previous post for the MEXT list). In addition, MEXT seems to think the fallout after the first two to three months of the accident (March through May, 2011) is due not to the Fukushima accident but to the past atmospheric nuclear testing because the measured amount did not exceed the amount prior to the Fukushima accident.

Outside Kanto and Tohoku regions, there are occasional detection of strontium-90 in:

Niigata City (Nishi-ku), Niigata: May 2
Imizu City, Toyama: April 1
Kakamigahara City, Gifu: July 1
Shizuoka City (Aoi-ku), Shizuoka: August 1
Yokkaichi City, Mie: May 2
Kyoto City (Fushimi-ku), Kyoto: April 1
Wakayama City, Wakayama: November 1
Okayama City (Minami-ku), Okayama: April 1
Ishii-cho (Myozai-gun), Tokushima: April 1
Takamatsu City, Kagawa: April 1
Matsuyama City, Ehime: April 1
Kochi City, Kochi: April 1

Likewise, none of the detections above is considered by MEXT as the result of the Fukushima accident.

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Radioactive Fallout in Futaba-machi, Fukushima Rose in February 2012

At 6PM on Friday March 30, 2012, the Ministry of Education and Science (MEXT) released the measurement of radioactive fallout in prefectures in Japan for the month of February 2012 (here's the link).

The fallout measured in Futaba-machi, Fukushima has increased by more than 70% over the January figure to 33,300 megabecquerels/square kilometer (or 33,300 becquerels/square meter):

MEXT is in the process of reorganizing their website, changing the links to the past data. It has screws up my bookmarks.

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Radioactive Fallout in Futaba-machi, Fukushima in January 2012: 19,120 MBq/Square Kilometer

The Ministry of Education and Science released the data on radioactive fallout by prefecture in January 2012, on March 23.

For Fukushima Prefecture, it is measured in Futaba-machi, where Fukushima I Nuclear Power Plant is located. The measurement for the month of January, 2012 was:

Cs-134: 8,020 Mbq (megabecquerels)/km2
Cs-137: 11,100 MBq/km2
Total cesium: 19,120 MBq/km2

The measurement in Fukushima in Futaba-machi started in September 2011. From September to November, the numbers were in 4 digits. The fallout amount jumped in December, as you see in the table below (created from the data at MEXT website):

There was a similar jump, albeit much smaller, in the fallout measured in Fukushima City starting December 2011. The increase in Fukushima City has been attributed to winds blowing the dusts. (FYI, here's the latest fallout data for Fukushima City.)

West of Shizuoka, it's all ND. Miyagi is supposed to have started measuring the fallout in March this year.

From MEXT announcement on March 23, 2012, "Reading of environmental radioactivity level by prefecture (Fallout)(January, 2012)"

Prefecture City	Fallout#
	I-131	Cs-134	Cs-137	Other detected nuclides
1	Hokkaido Sapporo	ND	ND	ND
2	Aomori Aomori	ND	ND	ND
3	Iwate Morioka	ND	1.6	2.0
4	Miyagi	-	-	-
5	Akita Akita	ND	0.069	0.086
6	Yamagata Yamagata	ND	3.0	3.9
7	Fukushima Futaba	ND	8020	11100
8	Ibaraki Hitachinaka	ND	15	18
9	Tochigi Utsunomiya	ND	16	20
10	Gunma Maebashi	ND	3.3	4.1
11	Saitama Saitama	ND	7.6	9.8
12	Chiba Ichihara	ND	7.1	11
13	Tokyo Shinjuku	ND	8.9	11
14	Kanagawa Chigasaki	ND	2.6	3.2
15	Niigata Niigata	ND	0.084	0.087
16	Toyama Imizu	ND	ND	ND
17	Ishikawa Kanazawa	ND	0.068	0.090
18	Fukui Fukui	ND	ND	ND
19	Yamanashi Kofu	ND	0.41	0.54
20	Nagano Nagano	ND	1.3	1.6
21	Gifu Kakamigahara	ND	ND	ND
22	Shizuoka Shizuoka	ND	0.34	0.51
23	Aichi Nagoya	ND	ND	ND
24	Mie Yokkaichi	ND	ND	ND
25	Shiga Otsu	ND	ND	ND
26	Kyoto Kyoto	ND	ND	ND
27	Osaka Osaka	ND	ND	ND
28	Hyogo Kobe	ND	ND	ND
29	Nara Nara	ND	ND	ND
30	Wakayama Wakayama	ND	ND	ND
31	Tottori Touhaku	ND	ND	ND
32	Shimane Matsue	ND	ND	ND
33	Okayama Okayama	ND	ND	ND
34	Hiroshima Hiroshima	ND	ND	ND
35	Yamaguchi Yamaguchi	ND	ND	ND
36	Tokushima Myozai	ND	ND	ND
37	Kagawa Takamatsu	ND	ND	ND
38	Ehime Matsuyama	ND	ND	ND
39	Kochi Kochi	ND	ND	ND
40	Fukuoka Dazaifu	ND	ND	ND
41	Saga Saga	ND	ND	ND
42	Nagasaki Omura	ND	ND	ND
43	Kumamoto Uto	ND	ND	ND
44	Oita Oita	ND	ND	ND
45	Miyazaki Miyazaki	ND	ND	ND
46	Kagoshima Kagoshima	ND	ND	ND
47	Okinawa Uruma	ND	ND	ND

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Mysterious Spike in Cesium Fallout in Fukushima on Jan 2, 2012 (Updated with Chiba Information)

The spike happened one day after the pretty big earthquake (seismic intensity scale 4) on January 1, 2012, which caused the water level of the Skimmer Surge Tank of Reactor 4 to fluctuate unexpectedly.

Only the people on the net paid attention to the data and it was not reported by the MSM. The Ministry of Education and Science issued the result of the fallout measurement, without saying anything as to why these dates (12/27/2011 to date) are being singled out.

This person tweeted the pic with three overlapping charts comparing (from the top): (1) amount of snow on the ground and amount of rain, (2) amount of cesium fallout, and (3) wind speed (average speed in black, maximum speed in blue, and maximum instantaneous speed in red), from December 1, 2011 to January 6, 2012:

The huge spike looks a few sigmas away from the norm, even with the wind speed picking up on January 2, 2012.

On Twitter, people in Tokyo were reporting strange white powder floating in the air several days ago, and people in Ibaraki and Chiba Prefectures were reporting elevated air radiation levels.

No news from the media, and these reports are dismissed by some on Twitter as "hysteria".

(UPDATE)

Inage District of Chiba City in Chiba Prefecture also had cesium fallout sometime between 12/26/2011 and 1/4/2012, according to the analysis by the Japan Chemical Analysis Center:

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Plutonium From Fukushima Detected in Lithuania

Not to show that the amounts were significant (they weren't) but to note that plutonium out of the Fukushima reactors did indeed travel far and wide, contrary to many nuclear experts (particularly the kind that live in Japan) have said.

What's more, the authors of the paper seem to think that plutonium came from the spent fuel.

Interesting. Does anyone have access to the full paper?

From PubMed.gov (US National Library of Medicine), emphasis is mine:

J Environ Radioact. 2011 Dec 27. [Epub ahead of print]
Radionuclides from the Fukushima accident in the air over Lithuania: measurement and modelling approaches.
Lujanienė G, Byčenkienė S, Povinec PP, Gera M.
Source

Environmental Research Department, SRI Center for Physical Sciences and Technology, Savanoriu 231, 02300 Vilnius, Lithuania.

Abstract

Analyses of (131)I, (137)Cs and (134)Cs in airborne aerosols were carried out in daily samples in Vilnius, Lithuania after the Fukushima accident during the period of March-April, 2011. The activity concentrations of (131)I and (137)Cs ranged from 12 μBq/m(3) and 1.4 μBq/m(3) to 3700 μBq/m(3) and 1040 μBq/m(3), respectively. The activity concentration of (239,240)Pu in one aerosol sample collected from 23 March to 15 April, 2011 was found to be 44.5 nBq/m(3). The two maxima found in radionuclide concentrations were related to complicated long-range air mass transport from Japan across the Pacific, the North America and the Atlantic Ocean to Central Europe as indicated by modelling. HYSPLIT backward trajectories and meteorological data were applied for interpretation of activity variations of measured radionuclides observed at the site of investigation. (7)Be and (212)Pb activity concentrations and their ratios were used as tracers of vertical transport of air masses. Fukushima data were compared with the data obtained during the Chernobyl accident and in the post Chernobyl period. The activity concentrations of (131)I and (137)Cs were found to be by 4 orders of magnitude lower as compared to the Chernobyl accident. The activity ratio of (134)Cs/(137)Cs was around 1 with small variations only. The activity ratio of (238)Pu/(239,240)Pu in the aerosol sample was 1.2, indicating a presence of the spent fuel of different origin than that of the Chernobyl accident.

Copyright © 2011 Elsevier Ltd. All rights reserved.

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"Now They Tell Us" Series: Radioactive Cesium Fallout in Fukushima from March to June Was 6.83 Million Becquerels

(UPDATE) The Ministry's other release says the measurement in Fukushima was done in July, therefore no detection of iodine-131 or any other short-lived nuclides. The Ministry sat on the data for only 5 months then.

===========================================


or 47 times as much as all the 45 prefectures (excluding Fukushima and Miyagi) combined.

Or 145 million times as much as the pre-accident annual number for Fukushima, in half a month.

It took only 9 months for the Ministry of Education and Science to finally disclose the number for Fukushima Prefecture. The Ministry is yet to say anything about Miyagi Prefecture.

The ostensible reason for not disclosing the numbers for Fukushima and Miyagi has been that the measuring stations got damaged by the earthquake. Well, by releasing the data, albeit very late, the Ministry makes it rather clear that the measuring station in Fukushima was just fine, and it had the data.

Still, the number is only for radioactive cesium (134 and 137). No word about radioactive iodine, or about any other nuclide.

From Asahi Shinbun (12/14/2011):

東京電力福島第一原発の事故で大気中に放出された放射性セシウムについて、文部科学省は１４日、事故後４カ月間で福島県に降った積算値は１平方メートルあたり６８３万ベクレルだったと発表した。文科省は先月、宮城、福島を除く４５都道府県の積算値を発表したが、最も多かった茨城県（４万８０１ベクレル）の１６８倍で、４５都道府県の合計値（１４万４４４６ベクレル）の４７倍に相当する。

Regarding the radioactive cesium that has been released into the atmosphere as the result of the Fukushima I Nuclear Power Plant accident, the Ministry of Education and Science announced on December 14 that the cumulative amount of radioactive cesium fallout in 4 months after the accident in Fukushima Prefecture was 6.83 million becquerels/square meter. The Ministry announced the cumulative amounts of radioactive cesium fallout for the 45 prefectures last month, excluding Fukushima and Miyagi. The amount in Fukushima is 168 times as much as that in Ibaraki Prefecture (40,801 becquerels) which had the highest amount among the 45 prefectures, and 47 times as much as the amount for the 45 prefectures combined (144,446 becquerels).

　各地の衛生研究所などで容器にたまったちりからセシウム１３４と１３７を測定した３～６月の積算値。福島県は震災の影響で分析が遅れていた。測定地は第一原発のある大熊町。６８３万６０５０ベクレルのうち９４％が３月に集中しており事故直後の深刻さがうかがえる。事故前にも大気圏内核実験による降下物などがあるが、福島県の０９年度の積算値は０．０４４ベクレル。

The numbers are the cumulative numbers, measuring cesium-134 and cesium-137 from the dusts collected in containers at institutes of public health throughout Japan from March to June. The analysis for Fukushima Prefecture was delayed because of the March 11 earthquake/tsunami. The measuring location was in Okuma-machi where Fukushima I Nuclear Power Plant is located. Of the 6,836,050 becquerels that fell [between March and June], 94% fell during March, attesting to the severity of the situation right after the accident. There was nuclear fallout from the past atmospheric nuclear testing before the Fukushima accident, but the cumulative fallout for Fukushima for the year 2009 was 0.044 becquerel.

For the entire year of 2009, Fukushima had 0.044 becquerel of radioactive cesium fallout.

In March of 2011, it had over 6.4 million becquerels. That's 145 million times more than the pre-accident level for a year, in half a month.

The Ministry of Education and Science's press release on December 14 (Japanese only) simply states the reason for the disclosure now as "The results just came in", on top of page 2.

Aside from cesium-134 and cesium-137, the press release also states the numbers for tellurium-129, tellurium-129m, and cesium-136. For the 4 months period in Fukushima, they are:

• tellurium-129: 528,936 becquerels/square meter

• tellurium-129m: 2,042,500 becquerels/square meter

• cesium-136: 247,000 becquerels/square meter (March only)

(The Ministry uses Mbecquerels/square kilometer.)

A smart move by the Ministry, I suppose, to disclose the worst number (in Fukushima) first before disclosing the number for Miyagi, which I suspect to be much higher than that of Ibaraki.

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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.)

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Japan's Idea of Decontamination: Give Manual to Citizens and Let Them Do It

So the vast tract of East Japan has been contaminated with radioactive materials that came out of nuclear fuel rods that were melted down (and through and possibly out), and many areas are more contaminated than the radiation control area of a nuclear power plant which requires strict control and decontamination by nuclear professionals in case of an accident.

So what have the affected municipalities done? Fukushima Prefecture already has a handbook for citizens on how to decontaminate. The national government has promised it will come up with a plan. (It reminds me of "Blackadder" - where Baldrick always say to Blackadder at the very last moment, "I have a cunning plan ..." which is not cunning and usually very bad or useless or both to say the least.)

That national plan may be something like the one that has been apparently released by the Japanese Society of Radiation Safety Management, and it relies on the citizens' effort to locate the high radiation "hot spots" and decontaminate using the household cleaning tools and materials, as if radioactive cesium and strontium and plutonium and cobalt should be no different from dirt and rust.

One great thing about this citizen decon idea is that it won't cost much at all to the national government, other than some support money given to neighborhood associations.

Asahi Shinbun (8/31/2011) reports:

個人の住宅周辺で特に放射線量が高い「ホットスポット」の見つけ方と、効果的な除染法について、日本放射線安全管理学会がマニュアルをまとめた。雨どいの下など、放射性物質が集まりやすい場所を紹介。放射性物質が飛散しない除染法なども説明している。

The Japanese Society of Radiation Safety Management has created a manual on how to find "hot spots" in and around one's home and how to decontaminate effectively. The manual shows the locations where radioactive materials tend to accumulate, such as under the rain gutters, and explains the methods of decontamination that do not spread radioactive materials.

　ホットスポットは、雨どい▽側溝▽排水溝▽マンホール周辺▽水たまりの乾燥跡▽さびた鉄材▽切り株や木材▽草木やこけの表面▽枯れ葉や土がたまった場所――などに多く見つかる。

[According to the manual,] hot spots are often found at rain gutters, side drains, manholes, locations where there were water puddles, rusted metals, tree stumps and lumber, surface of grass, trees and moss, pile of fallen leaves and dirt.

　雨どいや屋根の材質がさびたトタンや凹凸が激しい瓦の場合、セシウムが吸着しやすい。ちりや枯れ葉を掃除して集めると、線量が数十倍になることもある。

Cesium tends to adhere to the rain gutters, rusted tin roofs, and roofing tiles with uneven surface. If one sweeps dust and fallen leaves and collect them, the radiation level may jump significantly.

　家庭菜園で、３月中旬～下旬以降に枯れ葉などですき込み作業をした場合は、作物への放射性物質の移行に注意が必要という。

If dead leaves were plowed into the home garden after mid March, one should be aware that radioactive materials may have moved to the plants.

　屋根や雨どいを除染する場合はブラシを用い、汚れが落ちにくい場合は重曹水や酢を２～３倍に薄めた水を少しかけてこする。さびた部分は、オレンジクリーナーやクレンザーなどを使うと効果的だという。

According to the manual, one should use a brush to decontaminate the roof and rain gutters. If the dirt doesn't come off easily, one may wet the surface a little with water with baking soda or with vinegar and scrub. Cleanser is effective on rusty parts.

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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.)

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Another "Baseless Rumor": Cicadas in Japan This Summer Have Been Awfully Quiet

(Warning: Photos may be too disturbing to some people.)

This is one of those bits of information that people in Japan have been exchanging on the social media since the beginning of summer: "I don't hear cicadas this year".

A typical summer in Japan is hot and humid (except in a few lucky places like Hokkaido), and the air is filled with the "singing" of cicadas.

But this year, people report that cicadas are either extremely quiet or totally silent in large part of Japan. The exception seems to be the Kansai area, but almost everywhere else people say they don't hear cicadas, and it's been a strangely quiet summer.

It is quite possible that it's been like that every year and people have started to pay heightened and nervous attention to the nature around them after the nuclear accident.

But some people have started to post the photos of cicadas they've found this summer. No wonder they don't "sing". Again, it is quite possible that cicadas in Japan have been malformed for a long time and people have just started to notice, and it's nothing to do with radiation.

Picture of a cicada supposedly taken 60 kilometers from Fukushima I Nuke Plant, on July 22:

A cicada 120 kilometers from the plant. The person who took the photo says on her August 15 blogpost that it was on the ground and trying to flap its wings, and died soon:

Cicadas 300 kilometers from the plant. The person who took the photo says in her blog that in normal year about 100 cicadas hatch in her garden between mid July and mid August but this year the hatching peaked out in early August. He/she also says the male to female ratio is very lopsided this year (way more females than males, and only males "sing" to attract females), and he/she's found 8 cicadas so far that were unable to get out of the shells and died before they could hatch. In a normal year, he/she finds only one or two that fail to hatch and die.

He/she suspects these cicadas may have gotten their radioactive nutrition from the roots of the trees that have been absorbing radioactive materials since the nuke accident. Radioactive fallout like radioactive cesium cannot have penetrated deep enough into the ground to affect cicadas directly.

Cicadas spend between 3 to 17 years underground before they hatch and live a brief summer. Some say only a week, others say as long as one month.

There is another possibility why cicadas are quiet, and that's not good either. It is said in the folklore that the summer before a big earthquake hits is very quiet without hardly any cicadas.

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#Radioactive Fallout in Tokyo in March: Iodine, Cesium, Tellurium, Radioactive Silver

Silver-110m, half life about 250 days, wouldn't have been discovered unless the control rods had melted at Fukushima I Nuclear Power Plant.

There was the news in early April that radioactive silver was detected in South Korea. There was no way the same nuclide wasn't falling in Japan if it could fly all the way to Korea, I thought.

Sure enough.

It was not until 2PM on July 29 that the Ministry of Education and Science announced the "reading of environmental radioactivity level by prefecture [Fallout]" for March 2011.

What's the point of telling us now? Just for the record?

Radioactive materials that were falling in the Kanto region in March, other than iodine-131, cesium-134 and -137, are:

Niobium-95
Tellurium-129
Tellurium-129m
Tellurium-132
Silver-110m
Cesium-136
Lantanium-140
Barium-140

They look to be the nuclides coming out of melted fuel rods. No plutonium, strontium or uranium are mentioned.

The level of radioactive iodine (131) and cesium (134, 137) is also markedly high in Kanto. It is particularly high in Tochigi and Ibaraki Prefectures, and it is higher in Tokyo than in Saitama or Chiba. The area with the elevated level of radioactive fallout includes Shizuoka and Nagano Prefectures. For details for other prefectures, please go to the Ministry of Education website.

March result (part):

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