著者

伊沢 正実 坪田 博行

出版者

Journal of Radiation Research 編集委員会

雑誌

Journal of Radiation Research (ISSN:04493060)

巻号頁・発行日

vol.3, no.2, pp.120-129, 1962

被引用文献数

5

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To evaluate hazards of environmental contamination due to fission products from nuclear weapon test explosions, determination of body burden of the radionuclides taken in human body is essential. Because urine analysis is one of the practical methods to estimate body burden, Cs-137 concentration in human urine has been surveyed in Osaka and Ishikawa Prefectures since the fall of 1959. From the results of analyses, time variation of Cs-137 concentration and difference between two sampling sites were discussed with respect to the fallout rate. Cs-137 body burden was estimated from the analytical results by assuming the exponential equation for continuous exposure : In November 1959 the values were 8.4 mμc in Ishikawa and 6.0 mμc in Osaka respectively. And they decreased to 3 mμc in October 1961 in both areas. These values were consistent with the results obtained by other methods. Cs-137 gonad dose could be calculated with these values assuming uniform distribution of Cs-137 in a human body. Gonad dose rate due to internally deposited Cs-137 at present is about 0.7 mrad/y, and gonad dose up to the present is in the range of 5 to 8 mrad.

著者

伊沢 正実 坪田 博行

出版者

Journal of Radiation Research Editorial Committee

雑誌

Journal of Radiation Research (ISSN:04493060)

巻号頁・発行日

vol.3, no.2, pp.120-129, 1962 (Released:2006-08-29)

参考文献数

16

被引用文献数

5

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To evaluate hazards of environmental contamination due to fission products from nuclear weapon test explosions, determination of body burden of the radionuclides taken in human body is essential. Because urine analysis is one of the practical methods to estimate body burden, Cs-137 concentration in human urine has been surveyed in Osaka and Ishikawa Prefectures since the fall of 1959. From the results of analyses, time variation of Cs-137 concentration and difference between two sampling sites were discussed with respect to the fallout rate. Cs-137 body burden was estimated from the analytical results by assuming the exponential equation for continuous exposure : In November 1959 the values were 8.4 mμc in Ishikawa and 6.0 mμc in Osaka respectively. And they decreased to 3 mμc in October 1961 in both areas. These values were consistent with the results obtained by other methods. Cs-137 gonad dose could be calculated with these values assuming uniform distribution of Cs-137 in a human body. Gonad dose rate due to internally deposited Cs-137 at present is about 0.7 mrad/y, and gonad dose up to the present is in the range of 5 to 8 mrad.

著者

坪田 博行

出版者

公益社団法人 日本分析化学会

雑誌

分析化学 (ISSN:05251931)

巻号頁・発行日

vol.9, no.9, pp.783-790, 1960-09-05 (Released:2009-06-30)

参考文献数

21

被引用文献数

1

著者

中根 周歩 坪田 博行 山本 真

出版者

一般社団法人日本森林学会

雑誌

日本林學會誌 (ISSN:0021485X)

巻号頁・発行日

vol.69, no.11, pp.417-426, 1987-11-25

被引用文献数

3

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広島県・府中町の花崗岩土壤を立地とするアカマツ林における, 伐採前後の土壤炭素の循環調査で得られたデータおよび伐採後のアカマツ林再生に関するデータに基づき, 伐採から森林再生に至る土壤炭素の循環動態を日平均気温および日降水量からシミュレートする数理モデルを構成した。このモデルによれぱ, A_0層量は伐採後10年で最小となりその後回復し, 約30〜40年で伐採以前の値にもどる。一方, 鉱質土層の腐植量は伐採直後の数年間, 枯死根からの腐植の供給によってやや増大するがその後30〜40年間減少を続ける。そのため, 伐採以前の値にほぽ回復するのに伐採後80年近く要すると思われた。土壤炭素のフローについては, A_0層の呼吸速度はA_0層量の, 鉱質土層中の腐植の分解速度はその腐植の蓄積量の変動バターンにそれぞれ類似した。一方, 全土壤呼吸は伐採後, 根の枯死による呼吸停止によって激減するが, その後の土壤有機物量の減少から増大, また根の呼吸の再生に伴って回復した。