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Volume 28 (1993)
- Issue 4 Pages 407-
- Issue 3 Pages 273-
- Issue 2 Pages 116-
- Issue 1 Pages 4-
Volume 28, Issue 1
Displaying 1-7 of 7 articles from this issue
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Masami ISAWA1993 Volume 28 Issue 1 Pages 4-6
Published: 1993
Released on J-STAGE: February 25, 2010
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Ryusi ICHIKAWA, Tomoko KUSAMA, Sadayoshi KOBAYASHI, Hiroshi TANOOKA, S ...1993 Volume 28 Issue 1 Pages 7-21
Published: 1993
Released on J-STAGE: February 25, 2010
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Naoya SATTA, Toshifumi BITOU, Kenzo NISHIMAKI1993 Volume 28 Issue 1 Pages 23-30
Published: 1993
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSTwo simple methods were developed to calculate migration rates of excess radioactive 210Pb from undisturbed soil profiles. The migration of excess 210Pb was described by one-dimensional differential equation with decay term under steady state. One method (method 1) assumes a constant migration rate of excess 210Pb in the ground. This assumption gives resultantly the constant initial concentration of excess 210Pb per unit bulk volume at the ground surface. The other method (method 2) assumes that the migration flux of 210Pb through the ground decreases only by radioactive decay. The latter method can estimate the travel time of 210Pb from the ground surface to any horizon of interest.
Undisturbed soil samples were taken at Kyoto City, Japan. 210Pb and 226Ra contents were analyzed to get an excess 210Pb profile in the ground. Each method was applied to the observed profile. The resultant migration rate was respectively found to be 0.70 and 0.25-1.00mm/y for methods 1 and 2. These results could be applied well to evaluate the stable Pb migration through the ground.View full abstractDownload PDF (1031K) -
Sangduk SA, Michio YOSHIZAWA, Masakuni NARITA1993 Volume 28 Issue 1 Pages 31-40
Published: 1993
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSA simplified method in which the equivalent doses in tissue or organs and effective dose for external photon exposure according to the ICRP 1990 Recommendations could be approximated by a single empirical expression is proposed. In this method, the position of an organ is assumed to be the main factor that determine its dose for external photon irradiation. Many organ depths with different body size for ages 1, 5, 10 years and adults were determined using the cross-sections of mathematical organ descriptions, and effective depth for approximating effective dose was obtained with the organ depths assigned to tissue weighting factors.
Compared with the precised data for adults by the Monte Carlo method, the simple expression gives good approximates for most of deep organs and effective dose within about 20% except some organs, especially for lateral geometry. It was found that irradiation geometry affects the variations in age-dependent effective dose, and that the effective depths for ages 1, 5, 10 years, normalized to the adults depth, are directly proportional to the cubic root of the body weight. The usefulness of the concept of effective depth was also discussed with regard to the specified point of effective does in the body, obtained from the combination of the depths for the three typical geometries.View full abstractDownload PDF (1300K) -
Itaru SATO, Naonori MASTUSAKA, Kunihiro SHINAGAWA, Haruo KOBAYASHI, Yo ...1993 Volume 28 Issue 1 Pages 41-45
Published: 1993
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSEfficacies of intraperitoneal injection of stable manganese for enhancing the elimination of incorporated 54Mn was studied in mice. At the start of the experiment, each mouse was given 37kBq of 54Mn and initial whole-body radioactivities were measured. Forty-eight hours after the injection, mice were given intraperitoneally a single dose of stable manganese at 0.3, 1.0, 3.0 and 10mg/kg, respectively. Then Whole-body retentions and principal organ distributions were measured at suitable intervals.
Whole-body retentions of 54Mn decreased markedly following the stable manganese injection, and the efficacies for elimination were estimated to be 45.3% for 0.3mg/kg, 59.6% for 1.0mg/kg, 71.4% for 3.0mg/kg and 78.0% for 10mg/kg. The substitution rates of incorporated 54Mn for the injected stable manganese were 61.5, 70.8, 79.5 and 83.7%, respectively, suggesting that most of the manganese exists in free or exchangeable state in the body. The concentrations of 54Mn in organs also decreased by stable manganese injection, however, the efficacies for elimination varied with organs. It was generally effective in the soft tissues, and it was ineffective in the bone.
In conclusion, intraperitoneal injection of stable manganese was very effective to eliminate the incorporated 54Mn and it could reduce the risk of possible future biological effects.View full abstractDownload PDF (656K) -
Yuji NAKAMURA1993 Volume 28 Issue 1 Pages 47-61
Published: 1993
Released on J-STAGE: February 25, 2010
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Committee for Internal Dose Evaluation Code1993 Volume 28 Issue 1 Pages 63-76
Published: 1993
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSThe codes developed or being developed for internal dose assessment were reviewed. Firstly, the current research and development in ORNL were introduced based on the lecture of M. CRISTY in the meeting on April 4 in 1991 at NIRS. Secondly, the typical codes developed in Japan were described mainly on the characteristic aspects. Lastly, three codes in other countries were selected for notable codes having different features. Particularly, the code of LUDEP being developed by ICRP is noteworthy for the use of a new respiratory model and a user-friendly software.View full abstractDownload PDF (1827K)
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