Wildfires in Fukushima: reliable data or disinformation?

The forest fire in the Ide area of Namie in Fukushima prefecture, which occurred on April 29, has been going on for almost a week.

4月29日に発生した浪江町井出地区の山林火災が、ほぼ1週間たっても鎮火していません。

See video 消火活動動画
Video and photo sources 写真と動画の出典 : 陸上自衛隊第6師団; JGSD 6th Division

The major media reported it at the time of the outbreak, but except for some local television news, the fire has not been covered much. Furthermore, the news does not pop out immediately on web sites, and we have to make a considerable effort to find the information. Let’s keep in mind that most of the nuclear accident victims have only cellphones, and not PCs, which makes it very difficult to search for the information if it involves several clicks and the opening of PDF documents.

マスメディアは発生当時は報道したものの、テレビニュースの地方版を除いては、その後殆どこの火災を取り上げていません。また、各HP上で一面には出ず、かなり探さないと、記事が出て来ません。パソコンでなく携帯電話しか持たない、多くの原発被災者の皆さんにとって、何回もクリックしたり、PDFファイルをダウンロードしたりするのはほぼ不可能と言わざるを得ません。

The danger of the secondary dispersion of the radioactive substances is not mentioned at all in the announcement of Fukushima prefecture (see the picture below).

福島県のお知らせでは放射性物質の二次拡散の危険性について、全く触れられていません。(下の写真参照)

Equally, no mention is made about the danger on its homepage.

ホームページ上でも危険性には言及していません。

This is the announcement from Fukushima prefecture. The danger of the secondary dispersion of radioactive substances is not given to the residents, though it’s said that there is the possibility of repression of the fire.

こちらは福島県からのお知らせです。鎮圧のめどあり、と言っていますが、放射性物質の二次拡散の危険性については住民に通知はなしです。

18339657_939101659566432_743420143_o

As for the media, about the secondary dispersion of the radioactive substances that accompanies the fire, they say that there is no change in the radioactivity measurement values at present, and that there is nothing to worry about. The local newspaper Fukushima Minyu (in Japanese) calls for attention to the hoax about radiation risk.

また、報道では火災にともなう放射性物質の二次拡散について、今のところ測定値に変化はなく、憂慮する事態ではないとし、地元新聞の福島民友はデマに注意という方向で情報を伝えています。

The information source of the risk of secondary dispersion of radioactive substances used by the media is the data of airborne radioactivity measurements by monitoring posts and the airborne dust measurement published on the Fukushima prefecture website. 

報道に使われている、放射性物質の二次拡散の危険性が僅少であることの情報ソースは福島県のホームページに掲載されている大気中の浮じんデーターとモニタリングポストによる空間線量率です。

For those who have difficulties to open the PDF files, please look at the pictures below.

PDFファイルを開けない方は下の写真をご覧ください。

data dust page 1

data dust page 2

data dust page 3

Are these data reliable?

このデーターは信頼できるものでしょうか?

In addition, the public relations of Fukushima prefecture as well as the major media say that there is no influence on inhabitants’ life and health because there is little variation in the airborne radioactivity measurements. Do the measurement values of the individual dosimeters or of the nearby monitoring post help the residents to judge the situation?

また、福島県の広報や報道では、空間線量率の変動が少ないことから、生活や健康に影響はない、と伝えています。個人の線量計や付近のモニタリングポストの示す、空間線量率の数値は住民の皆さんが状況を判断する助けになるのでしょうか?

Currently, the “Fukuichi (Fukushima Daiichi) Area Environmental Radiation Monitoring Project” group and “Chikurin-sha” are collecting the data of airborne dusts by setting up linen and dust samplers.

現在、「ふくいち周辺環境放射線モニタリングプロジェクト」グループと「ちくりん舎」がリネンとダストサンプラーを設置、大気中の浮じんの採取中です。

We have received comments from Mr Yoichi Ozawa of the “Fukuichi Area Environmental Radiation Monitoring Project”, that we are reporting below.

私たちは「ふくいち周辺環境放射線モニタリングプロジェクト」の小澤洋一さんからコメントをいただいたので、以下にお伝えします。

___ ___   ___  ___  ___

【放射能の問題は、汚染の増加】
A. 空間線量率(Sv/h)だけを見ていてはだめ

・線量(Sv)は人体への被ばくの影響を表す単位で、環境の汚染(Bq)を表す単位ではありません
・プルームにより、どれだけ汚染が侵攻してきたかを評価します
・代表機種は、周辺の環境を除染後に設置し地表高1メートルを測定するモニタリングステーション(MP )です
・MPはガンマ線だけの測定で、ベータ線量やアルファ線は対象外の扱いになり、そこが汚れているという環境汚染の評価には不向きです
・MPは10分間の平均値を表わし、数秒間だけ汚染プルームが通過したとしても結果は反映されません
・線量が高くても、汚染が少なければ内部被ばくの心配は薄れます

A. Airborne radioactivity measures in terms of sievert are not appropriate.
“The problem is of that of the increased radio-contamination”

-The sievert is a measure of the health effect of ionizing radiation on the human body, and not a unit of measure of the environmental contamination (becquerel).
-It evaluates how much pollution has come in with the radioactive plume.
-The representative measuring device is a monitoring post (MP) that measures the radiation dose at one meter from the ground. The monitoring posts are installed after the decontamination work of the surrounding environment.
-MP measures only gamma rays, beta and alpha rays are not covered, and thus it is not suitable for environmental contamination evaluation.
-MP gives an average of 10 minutes measurements. Consequently, the result cannot reflect the passage of radio-contaminated plumes of a few seconds.
-Even if the dose is high, if there is less contamination, the fear of internal irradiation is less.

B. 福島県の大気中浮じんの発表データの信頼性

・環境中でのプルーム採取時間が短すぎる、大気は流れている
通常の原子力施設では、ダストサンプリングは20分程度だそうです。密閉された部屋の空気を全部吸い込むからです。しかし、環境中ではすべての空気を吸い込むことは、できません。ですから、長時間採取、長時間測定が必要になります。私たちのサンプリングは一週間、測定は2~4日程度です。
・測定時間が短すぎる、セシウム134が検出されるまで測定すべき
・事故前のデータと比較すべき
・すべてのデータが不検出、または、新たな基準に合致するように仕組んでいると考えざるを得ない。

B. Reliability of the data on airborne dust published by Fukushima.

-The time period of the plume collecting in the environment is too short. The air is flowing.
In normal nuclear facilities, dust sampling takes about 20 minutes. It is because all air in the sealed room is absorbed in this time. However, it is not possible to absorb all air in the open environnent. Therefore, it takes a long time to collect the dust and to measure it. In our case, it takes us a week for sampling and from 2 to 4 days for measurement.
-The measurement time is too short. They should continue measuring until cesium 134 is detected.
-The result should be compared to the data before the accident.
-We cannot help thinking that all data are organized in such a way that they are either under the lowest limit (marked as ND – Non Detected) or they conform to the new standards.

リネンは10ヶ所、エアーダストサンプラーは2ヶ所で稼働しています。 リネンの設置は、「ふくいち周辺…」のように、火災現場を取り囲んでいます。浪江町、双葉町、大熊町、田村市、葛尾村、南相馬市のように、全体的に取り囲んでいます。

We have installed linen cloths at 10 locations and air dust samplers in 2 places. The installation of linen surrounds the fire scene, like in the case of usual measurements of “Fukuichi Area Environmental Radiation Monitoring Project”. They are installed in Namie Town, Futaba Town, Okuma Town, Tamura City, Katsurao village, and Minami Soma City, surrounding the scene of the forest fire (Mount Jyuman in the map).

good map jyuman Eng

放射性物質の2次拡散について、結論を出すのは時期尚早です。

It is premature to draw conclusions about the secondary dispersion of radioactive materials.

鎮火後、3~4日後にピークがくるものと考えています。でも、その後風雨で汚染の移動はつづくでしょう。

I think that the peak will come after three to four days after the extinction of the fire. But then, the contamination will continue to move with the wind and rain.

また、落ち葉の測定結果のまとめも進行中です。浪江町と葛尾村の境界、火災現場から4~5km 西のものです。大柿ダムよりは低い汚染量ですが、燃やした灰も測定しています。

In addition, a summary of the measurement results of the fallen leaves is underway. They are from the border between Namie Town and Katsurao Village, which is 4-5km west of the fire site. The contamination is lower than that of the fallen leaves collected at the Ogaki dam. We are also measuring the burnt ash.

「ふくいち周辺環境放射線モニタリング・プロジェクト」のメンバー、田村市都路地区在住の深田和秀さんと取り組んでいます。 落ち葉、5,710 Bq/kg が燃やすことで、 19,500 Bq/kg と3.4 倍濃縮しました。手を加えて燃やすと、30倍ほど濃縮しますが、自然ではこんなものだと思います。

We are working with Mr. Kazuhide Fukada, another member of “Fukuichi Area Environmental Radiation Measuring Project”, living in Miyakoji District, Tamura city. When we burn the fallen leaves measuring 5,710 Bq/kg, we obtain the ash of 19,500 Bq/kg that is, 3.4 times more densly contaminated in terms of weight. We can concentrate the contamination up to about 30 times artificially, but I think this is about the value in the natural environment.

___  ___ ___ ___

ほぼ2週間後には市民グループによる大気中浮じんのデータが得られるものと思われます。情報が得られ次第拡散させていただきます。

しかし、今回の火災で環境汚染の流動性は異なってくると考えられ、短期的ではなく、長期的な監視が必要と思われます。鎮火に至った時点で観察を停止し、関心を払わなくなることが最も危険なのではないでしょうか。今の報道はその方向に向いているように思われます。

東電福島第一原発事故直後に政府は「ただちに健康に影響はありません」と繰り返しました。マスコミは福島から逃げ、東京から「福島は安全だ」と報道しました。

私たちはこれらの事実を忘れていません。

In about two weeks, the data on airborne dust by the citizen groups will come out. We will publish the information as soon as it is known.

However, it is likely that the the environmental contamination fluctuation will become different by this fire, and we need long-term rather than short-term monitoring.
It would be most dangerous to stop monitoring and paying attention after the fire is extinguished. The current media reports seem to be leading us to that direction.

Just after the Tepco Fukushima Daiichi accident, the central government repeated many times that “there is no immediate risk on health”. The major media fled from Fukushima, and they diffused the news from Tokyo, saying that there was nothing to worry about in Fukushima.

We have not forgotten.

_____

ふくいち周辺環境放射線モニタリング・プロジェクト」HP

Fukuichi Area Environmental Radiation Monitoring Project web site (in Japanese)

8 thoughts on “Wildfires in Fukushima: reliable data or disinformation?”

  1. Thank you for this article. I realise it may be early to say but what are the perceived risk increases for those living in Tokyo area (inhalation and ingestion)?

    Like

    1. Hi, Steve
      Thank you for the comment. The data on fallout in the Tokyo metropolitan region in May will come out on July 31. It is very difficult to forsee, but at least you should wear a mask and be concerned about where your food comes from.

      Like

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