http://ex-skf.blogspot.com/2012/05/black-dust-in-tokyo-with-243000-bqkg-of.html
MONDAY, MAY 14, 2012
"Black Dust" in Tokyo? With 243,000 Bq/Kg of Radioactive Cesium
Freelance journalist Rei Shiva [Shiba] writing for Nikkan Spa, a daily tabloid in Japan (part; 5/15/2012):
福島県南相馬市内で発見された超強力な放射能を持つ謎の“黒い粉”が話題になったのは今年２月のこと。It is 2,430 times the clearance level [100 Bq/kg] specified by the Nuclear Reactor Regulation Law.
It was this February when the super-radioactive and mysterious "black dust" found in Minami Soma City in Fukushima Prefecture was in the news.
1kgあたり108万ベクレル」というケタ違いの線量は衝撃的なものの、「南相馬での特殊な事例」として受け止められていた。ところが、その「黒い粉」は東京都内の至るところに存在しているという。
Although 1.08 million Bq/kg was shocking, it was considered to be specific only to Minami Soma. However, I've been told that "black dust" exists everywhere in Tokyo.
「放射線検知器を近づけてみると、明らかに反応があるので、汚染度が高いのかなとは思っていたのですが、まさかここまでとは……」「黒い粉」を都内で発見した、市民団体「NO！放射能 江東こども守る会」の石川あや子代表は驚きを隠せない。「江戸川区のJR平井駅周辺で『黒い粉』らしきものを見つけ、採取したサンプルを神戸大学の山内知也教授に検査してもらったところ、最大で１kgあたり24万3000Bqという数値が出たんです」。
"When I brought the radiation detector closer, it visibly responded. So I knew it might be highly contaminated, but didn't know it was this contaminated...", says Ayako Ishikawa incredulously. Ishikawa is the head of the citizens' group "No! to Radiation, Protect Children in Koto". [Koto-ku is one of the eastern Special Wards of Tokyo]. She says, "We found something that looked like "black dust" near the Hirai JR station in Edogawa-ku. We collected the sample and and asked Professor Tomoya Yamauchi of Kobe University to measure the radiation. The result was that it had the maximum 243,000 Bq/kg [of radioactive cesium]."
これは原子炉等規制法で定められた「安全基準（クリアランスレベル）」の約2430倍という、途方もない数値だ。
「注意して見ると、『黒い粉』は都内の至るところにあります」と石川さんは言う。そんなにあちこちに高汚染の物質が転がっているのだろうか？ という疑問を抱えつつ、「黒い粉」の調査に本誌記者も同行した。
"If you look carefully, "black dusts" are everywhere in Tokyo", says Ishikawa. Such highly contaminated materials are everywhere? I decided to accompany her to look for "black dusts".
まずは、JR平井駅から徒歩10分ほど。公営団地そばの運動場で「黒い粉」を発見した。フェンス近くで何か所にもわたって吹き溜まっていた「黒い粉」は、一見すると黒い土のように見える。近づいてよく見てみると、乾燥して干からびたコケやカビのようなものであるとわかる。
First, [to a location] about 10-minute walk from the JR Hirai Station. We found the "black dust" on the playground near the public housing. There were several drifts near the fence, and they looked like just "black soil". When I took a closer look, they were revealed to be something like a dried moss or mold.
「この前来たときと微妙に場所が変わっていますね。風雨で移動したのかもしれません」と石川さん。ガイガーカウンターよりも信頼性の高い、国産のシンチレーション式放射線検知器を「黒い粉」に近づけてみた。すると数値が急上昇し、毎時2μSvを超えた。東京都の平均的な空間線量（地上１ｍ）の約20倍だ。山内教授は「一般的に携帯式の放射線検知器は周囲の放射線量の平均値を表示します。つまり、少量の物質に検知器を向けて数値が急上昇するならば、その物質が極めて強い放射線を出している可能性があります」という。
Ishikawa said, "They are at slightly different locations. Rain and wind may have moved them." We measured the radiation with the scintillation survey meter made by a domestic manufacturer because it is more reliable than a geiger counter. The number shot up quickly, and exceeded 2 microsieverts/hour. That is twenty times more than the average air radiation level (at 1 meter off the ground) in Tokyo. Professor Yamauchi says, "In general, a scintillation survey meter shows the average radiation level. If the number rises rapidly when the survey meter is directed toward a small amount of substance, it is possible that the substance is emitting extremely strong radiation."...
果たして、「黒い粉」の正体とは何なのか？ そして、「黒い粉」の性質を利用した効率良い除染方法とは？ 5月15日発売の週刊SPA！「首都圏を襲う［放射能の黒い粉］」では、「黒い粉」の元になる物質の怖さのみならず有用性もまた報じている。
What is this "black dust"? What is the efficient decontamination method using the unique properties of the "black dust"? Shukan Spa [weekly magazine] that will go on sale on May 15 has the article "Radioactive black dust striking the Tokyo Metropolitan area", which will report on the danger of the substance that makes up the "black dust" as well as its usefulness.
I don't see much point in comparing it to the clearance level of 100 Bq/kg which is applicable only to enclosed nuclear facilities. After the Fukushima nuclear accident, it's a whole new ballgame where the disaster debris exceeding that clearance level is being shipped to Kyushu to be burned in a regular incinerator and the soil samples in Kanto and Tohoku easily exceed that level in many locations.
Even though I have reported on the "black dusts" in Minami Soma City (most recently, here), I am not completely convinced that this "black" substance is any different from a drift of dirt that one often saw on the road surface or near the drains even before the Fukushima nuclear accident. Cyanobacteria that supposedly make up the "black dust" are ubiquitous.
Professor Yukio Hayakawa of Gunma University says if the top 1 millimeter of the soil is taken the radioactivity can be extremely high, though he seems to think that "black dust" is a very good indicator of urban contamination.
No matter what it is or how it came about, it is clearly highly radioactive, and it'd better be removed to avoid contact. No municipalities are doing that, as they should.
Just don't go multiply that number (243,000 Bq/kg) by 65 and exclaim "Look, Tokyo is more contaminated than Chernobyl exclusion zone!" The multiplier of 65 only applies to soil samples that are taken from the surface to 5 centimeters deep, and whose specific gravity is about 1.3g/cm3. If Tokyo's "black dust" has the same weight as Minami Soma's "black dust", it would be less than 0.5g/cm3.
Even though I have reported on the "black dusts" in Minami Soma City (most recently, here), I am not completely convinced that this "black" substance is any different from a drift of dirt that one often saw on the road surface or near the drains even before the Fukushima nuclear accident. Cyanobacteria that supposedly make up the "black dust" are ubiquitous.
Professor Yukio Hayakawa of Gunma University says if the top 1 millimeter of the soil is taken the radioactivity can be extremely high, though he seems to think that "black dust" is a very good indicator of urban contamination.
No matter what it is or how it came about, it is clearly highly radioactive, and it'd better be removed to avoid contact. No municipalities are doing that, as they should.
Just don't go multiply that number (243,000 Bq/kg) by 65 and exclaim "Look, Tokyo is more contaminated than Chernobyl exclusion zone!" The multiplier of 65 only applies to soil samples that are taken from the surface to 5 centimeters deep, and whose specific gravity is about 1.3g/cm3. If Tokyo's "black dust" has the same weight as Minami Soma's "black dust", it would be less than 0.5g/cm3.
and....
http://ex-skf.blogspot.com/2012/05/ft-divisions-over-radiation-risk-have.html
MONDAY, MAY 14, 2012
FT: "Divisions over radiation risk have been exposed after Fukushima"
The article written by Mure Dickie and Clive Cookson for Financial Times that appeared in November last year seems to have engendered a lively discussion in the comment section regarding what is the "safe" radiation dose, if there is one.
From Financial Times (11/11/2011):
From Financial Times (11/11/2011):
Nuclear energy: A hotter topic than everIn May, radiation safety researcher Toshiso Kosako tearfully resigned as a scientific adviser to Japan’s prime minister after the government decided to set the limit for exposure in schools at 20 millisieverts a year, a level usually applied to nuclear industry workers. “It’s unacceptable to apply this figure to infants, toddlers and primary school pupils,” Professor Kosako said.
By Mure Dickie and Clive Cookson
Divisions over radiation risk have been exposed after Fukushima
In front of the government office in Japan’s Iitate village, the radiation monitor – a large metal box topped by warning lights – displays airborne levels in real time on a glowing digital display. A handheld dosimeter carried by local forester Toru Anzai gives more personal readings. In the nearby prefectural capital, sophisticated germanium detectors hum into the night analysing the radioactivity of local foods.
Eight months after a tsunami sent the Fukushima Daiichi atomic power station into near meltdown, data are pouring in across Japan on the scale of contamination caused by the world’s worst nuclear crisis in 25 years. Yet none of these detectors or their data can tell their users just how worried they should be. For the crisis has laid bare an absence of scientific and social consensus on radiation risk, which is undermining a disaster response already weakened by fractious leadership and an often slow-moving bureaucracy.
Uncertainty about radiation danger is not a problem for Japan alone. Atomic plants around the world are ageing fast, and more are being built in developing countries where there is often limited public oversight and high levels of corruption. It would be foolish for the world to assume that this crisis will be the last.
On one side, analysts say bowing to exaggerated fears of radiation will stunt global development of nuclear power, slowing economic growth and increasing pollution and global warming from fossil fuels. On the other, experts accuse the nuclear industry and government officials of playing down the dangers.
But Wade Allison of Oxford university says the 20mSv a year limit for evacuation should be raised to 100mSv a month, arguing that the principal health threat posed by the Fukushima Daiichi crisis is “fear, uncertainty and enforced evacuation”.
Underlying such stark differences lies a lack of clarity about what radiation does to the body at doses below 100mSv per year, the level at which an increase in cancer becomes clearly evident in epidemiological surveys. Prof Allison and many other scientists believe that, below a certain threshold, radiation is likely in effect to do no harm to health at all. However, the mainstream assumption is that even very low doses carry some risk, even if it is not yet measurable.
The result has been highly precautionary limits on artificial radiation exposure, such as an international safety standard for the public of just 1mSv in a year. That is less than half the exposure most people receive naturally from background radioactivity in rocks, soil and building materials, and from cosmic rays. This may make sense in normal times – but it means that in a crisis people tend to assume exposure above the limit is dangerous. The problem for authorities is that it is next to impossible to judge exactly at what point it will be safer to move a population away from the radiation or to limit its exposure by, for example, keeping children indoors and closing schools. Such moves themselves have health risks: evacuation can kill the elderly and thrust younger people into unemployment. Disrupted education can mar children’s future careers. Loss of exercise habits makes people vulnerable to illness and obesity.
David Boilley, a nuclear physicist and head of the French citizens’ radiation testing group Acro, believes the Japanese evacuation line of 20mSv a year is too high, but acknowledges that a 1mSv level would be unrealistic. French government experts have suggested setting the evacuation trigger at 10mSv per year – although this could mean adding another 70,000 people to the 150,000-200,000 evacuated from areas near Fukushima Daiichi.“Evacuation is terrible [and we] need to weigh the burden and benefit,” says Mr Boilley, whose group is helping with monitoring in Fukushima, adding that the appropriate trigger point varies not only by area and exposure but also by individual. “Where to put it? That’s a very hard question,” he says. “I am happy I am not a politician who has to decide.”
(Full article and the comment section at the link)
Professor Wade Allison left his comment, saying:
I have written and explained in accessible language, but in some depth, why the evacuation level should have been set in the region of 100 millisievert per month, that is 1200 per year -- that is 60 times the current value, not five times, as quoted in this FT article.
Hey that means I was right, saying in my post that Professor Allison's annual limit was 1.2 sievert...
(H/T TS)
(H/T TS)
and.....
http://enenews.com/japan-physicians-1-million-will-develop-cancer-die-fukushima-according-experts-figures-video
Fukushima Video
Dr. Atsuo Yanagisawa* (by The Japanese College of Intravenous Therapy)
Uploaded by NewlynResearchGroup
Uploaded on May 8, 2012
Dr. Atsuo Yanagisawa* (by The Japanese College of Intravenous Therapy)
Uploaded by NewlynResearchGroup
Uploaded on May 8, 2012
Dr Yanagisawa graduated from the Kyorin University School of Medicine in 1976, and completed his graduate work in 1980 from the Kyorin University Graduate School of Medicine in Tokyo, Japan. Dr. Yanagisawa served as Professor in Clinical Medicine at the Kyorin University School of Health Sciences, and concurrently as Professor in Clinical Cardiology at Kyorin University Hospital until 2008. (Source)
At 3:00 in (Part II)
According to Dr. John Gofman, the author of ‘Radiation and Human Health’ [...] when these figures are converted to the population of Japan, then approximately 1 million people will develop cancer and die.
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