Tuesday, February 7, 2012

1.37 Million Bq/kg Radioactive Cesium in Earthworm Castings in Fukushima

There was a piece of news about 20,000 becquerels/kg of radioactive cesium found in earthworms collected in Kawauchi-mura, Fukushima Prefecture (20 kilometers from Fukushima I Nuclear Power Plant) in Mainichi Shinbun (2/6/2012).

The article says the researchers at the Forestry and Forest Products Research Institute, a government institution, found radioactive cesium in earthworms collected at 3 locations in Fukushima. The amounts varied significantly (from 20,000 becquerels/kg to 290 becquerels/kg), and the researchers (or Mainichi Shinbun reporter) attributed to the varying air radiation levels in these 3 locations.

Ummm, earthworms live in the soil, not in the air, I thought. Still, 20,000 becquerels/kg was high, until I read Professor Bin Mori's blog about his own experiment using earthworms.

Professor Mori found over 1.37 million becquerels/kg of radioactive cesium in excrement of earthworms he picked up in Watari District of Fukushima City, where radioactive cesium exceeding the national provisional safety standard (500 becquerels/kg) has been found in rice.

From Professor Mori's blog (2/6/2012):

生きとし生けるものはすべて放射能染してしまったのである(ミミズの銀とセシウムについて)

All God's creatures, great and small, have been contaminated with radiation (About radioactive silver and cesium in earthworms)

福島県を中心に、我々が採取してきた生物を厳密に測定すると、これまで放射性セシウム汚染していない生物はいない。だから、このブログの最後に示す本日の毎日新聞の報道のようにミミズも当然放射性セシウム汚染している。

Our study on the living organisms collected in and around Fukushima Prefecture shows that there is no organism that is not contaminated with radioactive cesium. As the Mainichi Shinbun reported today, earthworms are also contaminated.

小生は、東電福島第一原発から約60キロ離れた福島市渡利地区で、ミミズはもっとも土壌と接触している(土を丸ごと食べる!)から、強度にセシウム汚染しているに違いないと思って、長さ5センチぐらいのミミズを多数採取した。

I collected a lot of earthworms that are about 5 centimeters in length in Watari District of Fukushima City, about 60 kilometers away from the Fukushima I Nuclear Power Plant. Earthworms were in direct contact with soil, and so I assumed they would be highly contaminated with radioactive cesium.
    
  それを予備的にNaI検出器で一匹一匹調べた。多いものではCs-137が数万ベクレル/Kgあった。すべてのミミズが強く汚染していたが個体毎に非常にばらつきがあったのが不思議であった。

As a preliminary test, I used the NaI scintillation detector over each worm. On the high end, there were several tens of thousands of becquerels/kg of cesium-137. All worms were highly contaminated, but I wondered at why there were wide variations between the worms.
  
  よく観察すると、その理由として、ミミズに呑み込まれた土が体内にまだ残留しているミミズは放射性セシウム値が明らかに高いと思われた。

On closer observation, it seemed that the worm that still had the soil it had eaten remaining in the body tested high in radioactive cesium.

そこで、現場で偶然長さ30センチにわたる大きなミミズを捕まえていたので、これを、水で十分に洗って室温で放置して2週間にわたって糞を全部吐き出させて、乾燥させた。それをゲルマニウム半導体検出器で測定した。乾燥させた理由は、通常放射性セシウムの測定値を乾物重あたりで表示するためでもある。(写真1)

One of my catch was a large earthworm, 30 centimeters in length. So I washed it carefully with water, and left at room temperature for 2 weeks until it excreted all the castings and was dry. I measured [the worm and the castings] using the germanium semiconductor detector.
  
そうすると、このミミズの放射性セシウム値は顕著に少なかった(表1)。これは意外であった。

To my surprise, radioactive cesium in this worm was significantly less (Table 1). I didn't expect it to be this low.

Table 1: Radioactivity of earthworm in Watari District in Fukushima City
  

Radionuclides

Radioactivity (Bq/kg)

Ratio

Cs134

360

42

Cs137

480

Ag110m

20

1



さらに意外であったのは、ミミズの糞の放射能が驚くほど高かったことである(表2)。

Even bigger surprise was that the radioactivity in the castings was extremely high (Table 2).

Table 2: Radioactivity of the worm castings

Radionuclides

Radioactivity (Bq/kg)

Cs-134

569,032

Cs-137

804,340

Ag-110m

0


 
念のために、この場所の土壌の放射能も測定した(表3)。

I measured the radioactivity of the soil where I got the worm (Table 3).

Table 3: Radioactivity of the soil

Radionuclides

Radioactivity (Bq/kg

Ratio

Cs-134

37,629

345

Cs-137

44,031

Ag-110m

237

1


 

  ちなみにこのミミズがいたどぶのヘドロから1センチ離れた表面の放射線線量値は13.31マイクロシーベルト/時間という非常に高い値を示した。

The worm was found in the sludge of a ditch. The radiation level at 1 centimeters off the surface of the sludge was extremely high, at 13.31 microsieverts/hour.

計算の結果ミミズは土壌の放射性セシウムを0.01倍(840Bq/81660Bq)しか濃縮していないが、一方では放射性銀を0.085倍(20Bq/237Bq)に濃縮していた。

According to my calculation, the worm concentrated radioactive cesium in soil at a ratio of 0.01 (840 Bq/81660 Bq). On the other hand, it concentrated radioactive silver at a ratio of 0.085 (20 Bq/237 Bq).

ミミズの放射性セシウムに対する放射性銀の比は、土壌の放射性セシウムに対する放射性銀の比に対して、8.2倍(345/42)の濃縮率を示していた。つまり、セシウムよりは銀がはるかにミミズでも生物濃縮されやすいことがわかる。

The ratio of radioactive cesium to radioactive silver in the worm was 8.2 times the ratio in soil (345/42). In other words, in earthworms [as well as other living organisms we tested], radioactive silver tends to get concentrated more than radioactive cesium.      

また、ミミズの糞は土壌の放射性セシウムを16.8倍(1373372Bq/81660Bq)に濃縮していることがわかった。糞の放射性銀は検出限界以下であった。

Also, I found that radioactive cesium in the worm castings was 16.8 times as much as that in soil (1,373,372 Bq/81660 Bq). Radioactive silver in the worm castings was below detection level.      

ここで詳しくは述べないが、すべての生物において、放射性銀のほうが放射性セシウムよりも生物濃縮されやすい傾向にある。

I won't elaborate here, but there is a tendency in all living organisms [that I tested] that radioactive silver gets more concentrated in the organisms than radioactive cesium.
                
  私見では、下記の記事の森林総研の報道発表は、ミミズを体内に含まれている糞ごと測定している可能性が高い。     

In my personal opinion, the Forestry and Forest Products Research Institute, as reported by Mainichi Shinbun, is likely to have measured the radioactivity of earthworms with the castings that are still inside the worms.

Earthworms are near the bottom of the food chain in the forest. They eat dirt , or rather, eat organic materials already digested by bacteria and other organisms in the dirt. I am very curious to see if anyone has studied the effect of radiation in organisms such as bacteria in the soil.

What we need here is the ecologists who can evaluate the whole forest ecosystem, from the lowest in the food chain such as bacteria that break down the raw materials (such as fallen leaves) up the chain - worms, insects, frogs, lizards, fish, birds, and mammals. There is also another chain of concentration that may go like - bacteria that break down the raw materials, bacteria that feed nutrients from the breakdown of the raw materials to the plant root, worms, insects/lizards/birds that eats part of the plant.

Why study these, instead of human beings? Alternation of generations is much faster in them, so the effect of radiation may be easier to observe, if any.

But alas, only a handful of researchers in Japan seem even interested in studying. Most of those who did study seem to be waiting for their peer-review magazine debut.

Dr. Bin Mori is professor emeritus at the University of Tokyo Graduate School of Agricultural and Life Sciences. His specialty is plant nutrition.

19 comments:

farfromhome said...
This comment has been removed by the author.
netudiant said...

Welcome back!
I'm very glad that you are feeling better.
Re the topic:
Afaik, earthworms eat organic detritus, mostly fallen leaves and similar plant matter, rather than simply ingesting and digesting soil.
So it is no surprise that they carry a disproportionate radiation load in their gut and in their castings.
That said, it is obvious that this situation cries out for intensive and sustained study, to understand the impact of this disaster on the ecosystem of Japan. It is just irresponsible to close ones eyes to the challenge and sleepwalk into the future. The impact on everything from the microorganisms on up, through the entire food web, must be understood if Japan is to minimize the longer term damages this will wreak.
We know that TEPCO is talking of a 30-50 year period to eventually take down the site. So there must be a larger project, to capture all the effects and put them into context. This is something that Japan has world leading skills in doing. Why is it not getting the priority it deserves?

Anonymous said...

because it ain't over, studying is dumb, it's been done already. Studying is being behind, a backwards thinker and someone who is mentally sick. You need future forward types, not someone who revels pn the past. Research done, japan done/dead, fukushima not done, not by a mile/hardly begun. Run around with your notepads idiots, should have paid more attention before GAMBLING. Study that.

Anonymous said...

I made the previous post a;ternatech1@gmail.com + I say ALL fuel on site fissions/burns NOMATTER WHAT long ago +
www.fukushima-diary.com IS DOWN

Anonymous said...

ALTERNATECH1 I meant

Anonymous said...

RETARDS!!!!!!!!!!!!!!
UR RETARDEDNESS KILLED/KILLING HOW MANY?
LIFE LAND OCEAN FLORA&FAUNA GONE, LEFT TO SURVIVE IN LESS THAN, WHEN COULD HAVE BEEN MORE THAN?
ANSWER FOR ALL BUT ESPECIALLY 4 JAPAN WAS INTEGRATED NEUTRON POISONS
IDIOTS!!!!!!!!!!!!!!!!!!!!!!!!
AND I'M WORSE THAN JPN GOV TEPCO 2U RIGHT

Anonymous said...

SMART?
NO, NOT SMART, NO!!!!!
U PROVE NOT SMART JAPAN.
U PROVED IT!
NOT SMART
DUMB!!!!!
DUMB LIKE CHILD

Anonymous said...

YAH!!!!!!!!!!!!!! FUKUSHIMA-DIARY DOWN@@@@@@@@
YOU NEXT EX-KF
TEACH YOU TO GO AGAINST JAPAN/NIPPON
YOU MOTHERBASTARD

Anonymous said...

Here we go again.

Anonymous said...

on your moms ass, i swear to hari krishna we are nuclar waste

Anonymous said...

people need to eat crow right now, leave japan alon you malcontents

Mike said...

hi areva -- something seems to be amiss in this sentence: "there is a tendency in all living organisms [that I tested] that radioactive silver gets more concentrated in the organisms than radioactive silver." perhaps it should read "... than radioactive cesium"?
thanks again for all your efforts.

arevamirpal::laprimavera said...

@Mike, thank you. Yes it should have been "cesium" at the end of the sentence.

Maju said...

"earthworms live in the soil, not in the air, I thought"

Air and soil (and water) are not strictly separated entities. Surely air radiation comes from soil and/or reaches the soil (by microporosity or just rain, etc.) Earthworms must breath in any case, just as we do.

Anonymous said...

"IDIOTS!!!!!!!!!!!!!!!!!!!!!!!!
AND I'M WORSE THAN JPN GOV TEPCO 2U RIGHT"


Awww craap, not Arto Lauri's lubed buddy again...

Anonymous said...

Fukushima diary blog seems to be fine, you crazy ass troll.

Anonymous said...

No, Mr. Troll Dude, you are not worse than the Japanese government but you display paranoia, you don't seem to grasp anything anyone has written( including when they agree with you) and you are a total douche with your religious holier than thou shit. Fuck off yet again.

Anonymous said...

Well, now we know why so many birds are dropping dead. They eat worms and they feed huge amounts to their nestlings. The amount of radiation in the Japanese soil far exceeds the Chenobyl levels. It's a new paradigm for habitat destruction.

A curse and a pox on the nuclear cabal for killing so many species...you are higher up on the food chain and your turn is coming.

Your insane greed for money will not save you and your children from the poison of your dirty bombs at Fukushima Daiichi and all your other nuclear hellholes you call electricity-generators. In Japan you have destroyed one of the great wonders of the world in your mad quest for money.

Sayonara to the serenity and beauty of Japan...she is dying an ugly death she never deserved.

SP

Anonymous said...

aternatech1@gmail.com, are you masquerading as a Canadian now. Same toilet worthy droppings as the troll from Finland though. How smart.

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