7 Microsieverts/Hr Radiation Measured in Matsudo City, Chiba

According to Mainichi Shinbun (linked and translated below), the group of Japanese Communist Party assemblymen in Matsudo City in Chiba Prefecture released the result of their radiation survey of 144 locations in the city, and found 37 locations with over 1 microsievert/hour radiation. The highest was 7 microsieverts/hour. If you stand on the spot 24 hours a day for one year, you would get 61 millisieverts of external radiation.

Matsudo City, located on the western edge of Chiba Prefecture, are one of the cities and towns that have relatively high overall radiation in Kanto. (The map (version 4) is by Professor Yukio Hayakawa of Gunma University. Matsudo City is circled in red.)

The Communist Party assemblymen in the Tokyo Metropolitan Assembly did the similar survey of Tokyo back in May, which helped force the Tokyo government to start monitoring radiation in more details.

From Mainichi Shinbun (10/20/2011):

千葉県松戸市の共産党市議団は２０日、同市内の公園、民家、保育園など１４４カ所での空間放射線量の測定結果を発表した。１カ所あたり最大２５地点で測定し、農業用ビニールハウスそばで記録した毎時約７．０マイクロシーベルトが最高。３７カ所で同１マイクロシーベルト以上の地点があった。

The group of Japanese Communist Party assemblymen in Matsudo City in Chiba Prefecture announced on October 20 the result of the air radiation survey of 144 locations in the city. The locations included parks, private residences, and nursery schools. They measured up to 25 points in one location, and the highest radiation was recorded at the side of an agricultural greenhouse, at 7 microsieverts/hour. More than 1 microsievert/hour radiation was measured at 37 locations.

　調査には市民ら約１８３０人が参加し、先月７日から今月１７日、各地点の地上５センチで計測。同市議団は同約７．０マイクロシーベルトを記録した場所については「風評被害の恐れがあり、場所やその後の対応も答えられない」と話している。公園での最高値は西ノ下公園（同市西馬橋幸町）砂場の同約３．４２マイクロシーベルトで、連絡を受けた市が除染し、同０．３マイクロシーベルトに低下した。

1,830 Matsudo City residents also participated in the survey that was carried out from September 7 to October 17. The radiation was measured at 5 centimeters off the ground at each location. The group says it will not reveal the details of the location that measured 7.0 microsieverts/hour radiation for the fear of "baseless rumors". The highest measurement in parks was recorded at the sand box of Nishinoshita Park, at 3.42 microsieverts/hour. The group notified the city, who decontaminated the sand pit. The radiation was reduced to 0.3 microsievert/hour after decontamination.

　同市はこれまでも、市民が独自に測定した地点で再測定するなどし、既に約１０カ所で緊急除染を実施。今後も、公園などでより詳細な調査を進める。

The city has already carried out emergency decontamination at 10 locations after confirming the radiation measurements done by the city residents. It will conduct a more detailed survey in parks.

　砂場など特定の場所で局所的に高い汚染が確認される傾向が強く、同市議団は「比較的安全と考えられていた場所で突出した数値が出て驚いている。より細やかな調査が急務だ」と話している。

Localized, high radiation contamination has been consistently found in places like sand boxes. The group says, "We are surprised at the very high numbers in locations that have been considered relatively safe. We should make it an urgent task to conduct a more detailed survey."

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