保健物理
Online ISSN : 1884-7560
Print ISSN : 0367-6110
ISSN-L : 0367-6110
20 巻, 3 号
選択された号の論文の10件中1~10を表示しています
  • 渡部 輝久, 鎌田 博
    1985 年 20 巻 3 号 p. 227-240
    発行日: 1985年
    公開日: 2010/02/25
    ジャーナル フリー
    A literature study on the sources and behavior of 99Tc in the environment was made with 88 references. Special attention was directed to the description about the solubility of 99Tc in soil and its bioaccumulation in the terrestrial and aquatic environment. The description also includes a review of the data on such parameters as the distribution coefficient (Kd) and bioaccumulation factors, which are commonly used for radiological assessments of the environmental impact of the nuclear fuel cycle. Further efforts are expected to be made in order to complete understandings of 99Tc radioecology.
  • 山口 恭弘, 南 賢太郎, 大谷 暁
    1985 年 20 巻 3 号 p. 241-249
    発行日: 1985年
    公開日: 2010/02/25
    ジャーナル フリー
    The present paper describes the γ-ray attenuation coefficient and the dose buildup factor of various building materials, which are of great importance for estimation of the shielding effect of residential houses against γ-rays.
    The linear attenuation coefficients were measured for 19 building materials with γ-rays and filtered X-rays at energies ranging 44-1, 250keV. A corresponding atomic number, Zcor, was defined as an atomic number of the element having the mass attenuation coefficients akin to those of the material. According to Zcor, materials were classified into two groups: one is Zcor=7-9 and the other is Zcor=13-16.
    The dose buildup factors were measured for 4 materials selected from each material group with γ-rays and filtered X-rays at energies ranging 68-1, 250keV. It was found for the thin materials such as ordinary building materials, that the dose buildup factor could be represented approximately by the linear formula, BD=1+αμt, and α was characterized by both γ-ray energy and material group.
  • 高城 裕之, 木村 敏正, 小林 宏信, 岩島 清, 山県 登
    1985 年 20 巻 3 号 p. 251-257
    発行日: 1985年
    公開日: 2010/02/25
    ジャーナル フリー
    The pathway of iodine-129 mainly discharged into the atmosphere from nuclear fuel reprocessing plants can be copied by that of stable iodine because of its long half-life (1.6×107y). Among the routes of entry of iodine into the human body, the largest contribution seems to be made by the ingestion of rice in Japan. In view that the determination of 129I in rice is still not successful, the transfer of stable iodine from paddy field to rice grain has been studied by comparing the concentration in rice grain with that in soil on which the rice was grown. Polished rice and soil samples were collected in 1979 and 1980 from 14 Agricultural Experiment Stations throoghout this country. The methods of analysis are a radiochemical neutron activation technique developed by the authers. The results obtained are as follows:
    1) Fluctuations of the iodine concentrations between 1979 and 1980 are very small both in rice and soil.
    2) Except Iwate and Ibaraki Prefectures where the soil concentrations exceed some 10mg/kg, most soil contained around 1mg/kg (0.41-2.33 in 1979 and 0.61-2.46 in 1980) and general trend seems higher levels in Kanto and northern prefectures than in western ones.
    3) Rice level varied between 1.6-4.0μg/kg in 1979 and 2.5-5.0μg/kg in 1980. Coefficient of variation of rice level throughout this country is only 25% in both years.
    4) The average concentration ratio iodine in polished rice/total iodine in soil was calculated as 2×10-3, on the other hand, the ratio iodine in polished rice/water soluble iodine in soil was calculated as 2×10-1. It was suggested that the latter ratio was better to assess the iodine level in rice on the basis of soil levels.
  • 恵 和子, 辻本 忠, 岡 喬, 桂山 幸典
    1985 年 20 巻 3 号 p. 259-265
    発行日: 1985年
    公開日: 2010/02/25
    ジャーナル フリー
    Soil samples of surface layer were collected in Wakasa Bay area which is composed of various geologic properties. Concentrations of background radionuclides in soil samples were determined by γ-ray spectrometry with a coaxial type and a planer type of Ge(Li) detectors. The spectra of soil samples obtained by X-ray diffraction analysis show the characteristic composition of minerals based on the geologic properties of their mother's rocks. The concentrations of 238U, 226Ra, 228Ra and 40K in soil roughly correspond to the geologic properties. The highest concentrations of these four nuclides are the soil collected from granitic zone and next comes the soil from paleozoic zone. For homologous soil from granite and paleozoic the 40K contents decrease with increasing surface area, respectively. A good correlation between the 137Cs contents and the unsupported 210Pb contents was found in the soil samples of surface layer.
  • 草間 朋子, 板倉 周一郎, 吉澤 康雄
    1985 年 20 巻 3 号 p. 267-273
    発行日: 1985年
    公開日: 2010/02/25
    ジャーナル フリー
  • Ling-Nah SU, Pin-Chieh HSU, Pao-Shan WENG
    1985 年 20 巻 3 号 p. 275-277
    発行日: 1985年
    公開日: 2010/02/25
    ジャーナル フリー
    This paper deals with dose measurement in gonad and eyes with self-fabricated thermoluminescent dosimeters during CT scanning for brain. A female Rando phantom was used as the reference. The experimental results obtained from several patients show that for brain scan, the average eye dose was 169.5±204.1mrad/slice and gonad dose 0.20±0.15mrad/slice for male, and that for female was 195.3±193.2mrad/slice for eyes and 0.04±0.03mrad/slice for gonad. The results are also compared with that obtained from other models of CT scanner.
  • 土屋 武彦, 法村 俊之, 山本 久夫, 畠山 智
    1985 年 20 巻 3 号 p. 279-284
    発行日: 1985年
    公開日: 2010/02/25
    ジャーナル フリー
    The radiations emitted from the front surface of CRT of a color-television and a personal-computer display were measured by GM-counter. No difference was observed in the radiation dose between the cases with and without application of a high voltage to the CRT. The radiations were also measured by Si- and Ge-semiconductor spectrometers. It was found that the radiations emitted from CRT were composed of β- and γ-rays, and were essentially emitted from 40K and the nuclides of uranium- and thorium- series contained within the front glass of CRT. The exposure dose rate of these radiations at 50cm from the surface of CRT was, however, less than 1.6×10-3mrem/hr, and it was practically negligible in comparison with that of natural background radiations.
  • 岩崎 民子
    1985 年 20 巻 3 号 p. 285-290
    発行日: 1985年
    公開日: 2010/02/25
    ジャーナル フリー
  • 片桐 浩
    1985 年 20 巻 3 号 p. 291-297
    発行日: 1985年
    公開日: 2010/02/25
    ジャーナル フリー
  • 1985 年 20 巻 3 号 p. 345
    発行日: 1985年
    公開日: 2010/02/25
    ジャーナル フリー
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