doi: N/Apmid: N/A
The effect of stable scandium on the whole-body retention and tissue distribution of
doi: N/Apmid: N/A
A study of the total gonadotropins eliminated in 24-hr-urine samples carried out with 57 men with protracted irradiation during occupational exposures, showed a decrease in the amount eliminated in a significant number of subjects (P < 0.01). All but one was healthy and did not show any blood cell count alterations. One subject was suffering from a chronic irradiation disease. The film badge records during the last 5–10 yr showed doses lower than the maximum permissible. Though the mechanism of the lowering of the gonadotropic hormones secretion is not known, it may be supposed that this decrease contributes to the onset or the persistence of a vicious circle which brings about or keeps and/or aggravates the spermatogenesis alterations existent in subjects with long-term exposure to ionizing radiations.
doi: N/Apmid: N/A
A study was carried out in 31 young men (mean 33 yr) with long-term exposure (mean 8 yr) to microwaves. The investigation included a detailed andrologic questionary and semen analyses as well as determinations of total neutral 17-ketosteroids (17 ks) and total gonadotropin (t.g.) eliminations in 24-hr urine. The investigation showed a high frequency of libido decrease and sexual dynamic disturbances in the framework of the asthenic syndrome (70% of subjects) as well as various alterations of spermatogenesis in 74 % of the subjects. The alterations consisted of asthenospermia, hypospermia and/or teratospermia. The function of the testes leydigian cells, indirectly indicated by 17 ks determination, was normal. The normal or increased values of t.g. eliminations ruled out the possibility of the contribution of a hypothalamo-pituitary imbalance in the induction of germinal alterations shown in exposed men.
doi: N/Apmid: N/A
Incineration of radioactive waste has been found to be an excellent method for reducing both the bulk and the handling problems associated with the use of animals in a research institution. A cost analysis has been made at the University of Rochester for the incineration of certain wastes as compared to the cost of land burial. In determining the feasibility of incineration for a radioisotope the major factors to be considered are the activity, half-life, and maximum permissible air concentration of the isotope and the size of the carcass in which it is incorporated. Comparative examples are given for several specific isotopes in use at this institution. Environmental factors are also considered.
doi: N/Apmid: N/A
In spite of their very short half lives and/or low radiation energies, quite a number of the radionuclides produced during the operation of the high energy accelerators are to be treated as “unknown” nuclides, since their maximum permissible concentration (MPC) values are not listed in the table of ICRP Publication 2. Legal control values for these radionuclides are too strict, and this imposes unnecessary and difficult problems in the field of the high energy accelerator facilities. For these reasons, MPC values for radionuclides produced during accelerator operations, which are not listed in ICRP Publication 2, have been calculated according to methods of this ICRP publication.
doi: N/Apmid: N/A
A general description of a
doi: N/Apmid: N/A
Mesh wall ionization chambers are useful for determining the radial distribution of dose around a moving charged particle, by measuring the saturation ionization current. In order to evaluate and understand the saturation curves of the mesh wall ionization chamber, ionization current vs voltage curves were studied at pressures from 0.017 to 2 Torr in a large ionization chamber and in a small mesh wall ionization chamber located within the large chamber. Results indicate that saturation in the internal mesh wall chamber (probe) depends on (a) competition between collection in the probe and large ionization chamber, (b) recombination at very low voltages, (c) gas amplification at higher voltages, and (d) probe position. Saturation in the large chamber depends on recombination at low voltages and on gas amplification at higher voltages. For both the probe and large ionization chamber, collection of positive ions proved best; however, saturation voltages had to be chosen carefully at each pressure in order to achieve optimum balance of the above mentioned effects.
Showing 1 to 7 of 7 Articles