Minami Soma Assemblyman: "5.57 Million Bq/kg Cesium from Soil, and People Are Cleaning Out Their Homes"

Part of Minami Soma City in Fukushima was inside the "no-entry zone" but the designation was lifted as of April 16 this year and people are returning. One such area is Odaka District, and as NHK reported, the returning residents are being assisted by volunteers from all over Japan in cleaning up the damage from the March 11, 2011 earthquake and tsunami.

Minami Soma Assemblyman Koichi Ooyama says he went and collected soil samples (what he calls "black dust") in locations in Minami Soma, including several in Odaka District after the no-entry zone designation was lifted. He had them tested by the city's laboratory for radioactive cesium, and the result, as posted on his blog (5/10/2012) is shocking.  The maximum is 5,570,000 becquerels/kg of radioactive cesium in soil in Odaka District. In the same district, half a million becquerels/kg of cesium in cow dung was also found.

Mr. Ooyama lists those with high radioactive cesium content, because the numbers are not in sequence. English labels are by me. (Unit is bq/kg, dry weight):

①1,320,000 原町区牛越土壌 Haramachi District, soil
②1,960,000 鹿島区橲原土壌 Kashima District, soil
⑥5,570,000 小高区金谷土壌 Odaka District, soil
⑧　　16,200 原町区国見町土壌 Haramachi District, soil
⑪　793,000 小高区上町土壌 Odaka District, soil
⑫　430,000 小高区本町土壌 Odaka district, soil
⑬　583,000 小高区本町土壌 Odaka district, soil
⑭2,970,000 小高区金谷土壌 Odaka district, soil
⑰　522,000 小高区金谷牛ふん Odaka district, cow dung

Even if these samples are from areas where radioactive cesium is getting highly concentrated, I haven't seen numbers like this anywhere else in Fukushima outside the immediate vicinity of Fukushima I Nuclear Power Plant.

NHK News said the volunteers helping the home owners in Odaka District were scooping out the sludges - probably highly contaminated sludge - with hardly any protection other than flimsy masks and gloves. Who is going to be responsible if anything should happen to these volunteers later? Volunteers themselves.

Assemblyman Ooyama screams, "And they're going to do what? Spring athletic meets? Swimming pool opening? I can't take it any more!"

(For the mind-numbing routine in post-Fukushima Japan in spring and summer, see my previous post.)

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3.43 Million Bq/Kg of Radioactive Cesium in "Black Dust" in Minami Soma City, Fukushima

Whatever this substance is, the number is extremely high.

About this "black dust" in Minami Soma, see my past posts, here, here, here.

Minami Soma City's Assemblyman Ooyama reports on his blog (3/8/2012):

試料：ID:080 鹿島区ジサ原C
Cs-134 1,498,000 ± 1,586 Bq/kg
Cs-137 1,932,900 ± 2,481 Bq/kg
TOTAL 3,430,900± 2,945 Bq/kg

It seems to be part of the report by Professor Tomoya Yamauchi of Kobe University who did the measurement. Mr. Ooyama lists the result of 11 samples tested by Professor Yamauchi.

The NGO in Minami Soma, HCR, seems to have some kind of a fallout with the assemblyman's volunteer group over the "black dust", and they've been making rather wild announcements (telling residents that the black dust was plutonium, when there was no alpha emission was detected, for example). I am still trying to get the overall picture on this matter.

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More on Minami Soma's Mysterious Black Dust: Spectrum Analysis by Prof. Yamauchi, and High Alpha Radiation Detection by an NGO

The data sheet of the black dust with over 1 million Bq/kg of radioactive cesium from Minami Soma, as Professor Yamauchi measured, from Naoya Fujiwara:

Minami Soma's Assemblyman Koichi Ooyama says he simply took the sample to a laboratory in Minami Soma instead of waiting for the city officials to come back to work on Monday. The result, presented in his blog, was:

dried soil
Germanium semiconductor detector for 600 seconds
718,000 becquerels/kg [of radioactive cesium]
margin of error 10%

He says the sample was from a different location than the sample that Professor Yamauchi had tested. Assemblyman Ooyama says he will be giving a press conference at 11AM on Monday February 19.

In his blogpost, Ooyama mentions OPCOM institute of isotopes. It is an arm of the NGO called HCR (Heart Care Rescue) which has been active in supporting people in the nuclear disaster since last March.

HCR's Facebook page has additional information of the surface radiation levels of this mysterious substance:

【今消されたツイート】「黒い粉」通報によりHCRの専門部会OPCOM Institute of Isotopes緊急出動、放射線測定を済ませて只今帰還。南相馬市営住宅の駐車場でγ＋β＋α：61.321μSv/h、γ＋β：15.622μSv/h,残り45.699μSv/h：α線！

(Tweet that just got deleted) Emergency survey by OPCOM Institute of Isotopes, special arm of HCR, upon the discovery of "black dust". In the parking lot of a public housing project of Minami Soma City, measurement was:

γ＋β＋α：61.321μSv/h
γ＋β：15.622μSv/h
which means α: 45.699μSv/h

If this is the same public housing apartments that the blogger "Night that never ends" wrote about, then people, including children, have been living there.

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Over 1 Million Bq/kg of Radioactive Cesium from the Mysterious Black Dust in Minami Soma City

Minami Soma City assemblyman Koichi Ooyama discloses the result of the test of the mysterious black dust found in locations in Minami Soma City, Fukushima Prefecture.

A blogger whom I featured before, "Night that never ends", has been measuring radiation on the strange, black dust he finds in many locations in Minami Soma City, mostly on the road surface. His geiger counter (Inspector) measures all alpha, beta, gamma radiations and x-ray, and his measurement on the surface of this black dust was 295 microsieverts/hour.

Assemblyman Ooyama apparently sent the sample to Professor Tomoya Yamauchi of Kobe University. Professor Yamauchi did the test, and here's the result, from Assemblyman Ooyama's blog:

Cs-134: 485,252 Bq/kg
Cs-137: 604,360 Bq/kg

TOTAL: 1,089,612 Bq/Kg

Converting the total number to Bq/square meter,

1,089,612 × 65 = 70,824,780 Bq/m2

"Night that never ends" says in his blog this substance is very light-weight and blows off easily. He is finding it all over Minami Soma. He has asked the construction workers if it is from asphalt used in roads. The workers say no. To see the image of this black dust, go here.

"Night that never ends" says he has alerted the City Hall, and Mr. Ooyama indicates there will be a meeting with the city officials on this finding.

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