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Volume 21, Issue 1
Displaying 1-6 of 6 articles from this issue
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JOHN H. HARLEY1980 Volume 21 Issue 1 Pages 83-104
Published: March 15, 1980
Released on J-STAGE: July 14, 2006
JOURNAL FREE ACCESSThe plutonium that will be produced in the nuclear fuel cycle is a matter of extreme importance to regulators and to members of the public concerned with the environment. At the present time there is plutonium present in the environment on a global scale from weapons testing and from a satellite failure and on a local scale from nuclear operations and from the loss of nuclear weapons. The sensitivity of plutonium measurement has allowed us to study the present environmental levels of plutonium in the atmosphere, on the ground, in the oceans and in the pathways leading to man. This information, in turn, may allow us to predict the probable distribution of this material from any future contamination.
Since the present levels from even local contamination are low, it is desirable to be able to distinguish among the various sources, particularly distinguishing local sources from global fallout. When plutonium-238 is involved, alpha spectrometry can provide the contribution from this source. When the question involves the 239/240 ratio, mass spectrometry is necessary and only very high quality mass spectrometry is adequate for environmental levels of plutonium.
This paper will review our present knowledge of environmental plutonium and give some examples of problems where it has been necessary to distinguish among the various plutonium isotopes.View full abstractDownload PDF (1065K) -
MADHU KUMAR, ASHOK KUMAR, RAKESH MOHAN BHAGAT1980 Volume 21 Issue 1 Pages 105-110
Published: March 15, 1980
Released on J-STAGE: July 14, 2006
JOURNAL FREE ACCESSAdult, male house sparrows (Passer domesticus, Linn.) during recrudescence phase were divided into 4 groups. Gpoup i served as control ; group ii received total 2.5 mg of testosterone propionate (T. P.) ; group iii. birds were exposad to 450 R from a Co-60 source; group iv. birds were exposed to 450 R after administering 2.5 mg of T. P. There is no significant change in the body weight ih all the experiments. However, there is marked change in the testis weight in various groups. There is an increase in the testis weight of birds of group ii, but a significant decrease in the testis weight of birds of group iv. The testes show marked histopathological changes in group iv. The testes show depletion of spermatozoa, pyknotic spermatocytes, exfoliation of spermatids and formation of giant cells.View full abstractDownload PDF (342K) -
HIROYUKI OKABAYASHI1980 Volume 21 Issue 1 Pages 111-117
Published: March 15, 1980
Released on J-STAGE: July 14, 2006
JOURNAL FREE ACCESSIn case of the inhalation of plutonium nitrate (contained 241Am) aerosols in rats, the activity ratios of 241Am to total α activity in lungs of rats decreased with the elapsed day after inhalation. They were 11.84%, 11.00%, 9.46% and 8.40%, immediately after inhalation, 14 days, 32 days and 80 days after inhalation, respectively. These results showed that americium was more rapidly removed from lungs of rats than plutonium.
Therefore, when the lung burden of plutonium is suggested by the in vivo measurement used the γ-rays of 60 KeV emitted from 241Am, it should be noticed that the differential movement of these two elements exists.
On the other hand, the movement of 238Pu and 239, 240Pu in lung of rat was almost same during 80 days after inhalation.View full abstractDownload PDF (237K) -
A. SHIRAGAI, F. SATO, N. KAWASHIMA, S. KOBAYASHI, H. OTSU, M. SEKI, T. ...1980 Volume 21 Issue 1 Pages 118-125
Published: March 15, 1980
Released on J-STAGE: July 14, 2006
JOURNAL FREE ACCESSTo study on late effects by continuous gamma irradiations, the absorbed dose in mice was estimated in detail. A Cs-137 source was used for exposures. Dosimetry was performed with an air ionization chamber and a thermoluminescence dosimeter (TLD). The absorbed dose mapping of the gamma irradiation room was carried out by using the ionization chamber. Arcshaped racks with shelves made from wire net were designed on the basis of the dose map. The dose distributions in cages were measured under the racks and cages arrangements used during the experiments. Furthermore, by inserting TLD phosphors into abdomen of mice, exposure dose of the mice was actually measured under the experimental conditions.View full abstractDownload PDF (293K) -
H. MAEZAWA, T. MATSUURA, K. SUZUKI1980 Volume 21 Issue 1 Pages 126-136
Published: March 15, 1980
Released on J-STAGE: July 14, 2006
JOURNAL FREE ACCESSBacteriophage TI dried in a vacuum was irradiated with synchrotron orbital radiation (SOR) having a broad spectrum above 115 nm. For comparison, the phage was also irradiated with monochromatic 122 nm and 254 nm light in a dry state. When the phage was irradiated with SOR in a vacuum (above 115 nm), the fraction of host cell reactivation was larger than that irradiated with monochromatic 122 nm light but smaller than that irradiated with SOR under atmospheric conditions (light with wavelengths shorter than 190 nm being cut) or with 254 nm light. Photoreactivation of the phage irradiated with SOR was negligible. For the phage irradiated with 122 nm, no photoreactivation was observed. It may be concluded that the major photoproduct produced in dried phages by vacuum-uv light is different from the pyrimidine dimers of cyclobutane type which has been known to occur in phages irradiated with 254 nm light in a wet state.View full abstractDownload PDF (375K) -
N. ISHII, K. SUZUKI1980 Volume 21 Issue 1 Pages 137-147
Published: March 15, 1980
Released on J-STAGE: July 14, 2006
JOURNAL FREE ACCESSThe life-shortening effects of ultraviolet light (UV) and X-rays were investigated with a strain of free-living nematode, Rhabditidae tokai. UV exhibited a significant life-shortening effect on adult worms, and it also inhibited growth of larvae, hatching of eggs and reproduction. Sensitivity to UV was decreased with increasing ages. In contrast, nematodes showed a marked resistance to X-rays. Data were obtained suggesting that X-ray-induced singlestrand breaks in DNA can be rapidly and efficiently rejoined by a repair mechanism. Malformations were observed when immature larvae were irradiated with X-rays.View full abstractDownload PDF (543K)
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