For the estimation of tritium surface contamination by a smear technique, some experiments have been made on the optimum content of glycerol loaded in the smear paper, the fraction of tritium removed by the paper from the surface contamination (i. e., removal efficiency), the counting efficiency for a 2π gas flow counter, and the desorption of tritium from contaminated smear papers. Of the total contamination, 1% and 10% can be removed using a 25w/o glycerol loaded smear paper from a permeable material such as synthetic polymer resin tile and a non-permeable one like stainless steel plate, respectively. The counting efficiency for a tritium smear sample is about 10% for the counter. It is therefore appropriate to assume that the overall counting efficiency in this method (removal efficiency multiplied by counting efficiency) is 0.1% and 1% for the above two materials, respectively. The desorption of tritium is much less from a glycerol loaded smear paper, being only 20% in 40min, while it is as high as 70% from the non-glycerol loaded one.
Distribution in the body and excretion pattern of uranium have been investigated, following the inhalation of uranyl nitrate aerosols (concentration of uranium were 4.2μg/l and 26.4μg/l respectively) by adult rats. Amounts of uranium in the lung and the kidney immediately after the inhalation of the aerosol were about ten to several tens times greater than those in other organs, but decreased to the level of back ground after about one month. Following the single inhalation of the aerosol, the levels of uranium in liver, spleen, blood and bones were almost in back ground level during the period of one month thereafter. However, as the amout of uranium in the liver almost coincided with that of the spleen, it is estimated that the dose delivered to the spleen is more than ten times than that of the liver, in comparison of the both weights. The excretion of uranium in urine increases, according to the inhalation of uranyl nitrate. Therefore, uranium in urine is considered as a good index of the body burden of uranium for the estimation in case of the inhalation of the uranyl compound.
Nowadays, many types of personnel dosimeters are being used to monitor personnel doses. However it is generally difficult to determine organ doses by personnel dosimeters attached on surface of the body. Personnel monitoring should be controlled on each organ separately, because both external and internal doses should be considered for protection of radiation workers. According to the principle of personnel monitoring, it is neccessary to find a correlation between organ doses and indication of personnel dosimeters. In this study, LiF thermoluminescence dosimeters are used to measure organ doses in a human phantom (Alderson Co.), and LiF-TLD and pocket dosimeters (chamber type) are used as personnel dosimeters. The human body effect on correlation between organ and surface doses is also studied by some experiments. In order to acquire an angular response of any organ dose, three organs were chosen; testicles on surface of the body, ovary in the thick part of the trunk and liver in the comparatively thin part of the trunk.
This is a brief investigation of biological dosimetry for human subjects. During the past decade techniques have been developed for the analysis of radiation-induced chromosome aberrations in human lymphocytes. As a result, a vast amount of studies on chromosome aberrations induced by radiation in human lymphocytes have been carried out. These studies have revealed the relationships between aberration frequencies and absorbed doses. At present this method appears to be the most readily quantifiable one of biological dosimetry available. The problems associated with the use of this method in estimating radiation dose are discussed. These problems include time of sampling after irradiation, culture time, dose rate, type of radiation, temperature at the time of irradiation, etc.