Total activities due to the ingestion of 131 I were evaluated in different compartments of the human body of patients. It has been shown that the 131 I activity in urine of patients increases when the 131 I uptake decreases which could represent a source of radiation for their relatives when they leave hospitals. A new dosimetric model based on the specific betadose concept was developed for evaluating committed equivalent doses to thyroid due to 131 I uptake by different age groups of patients. Data obtained are in good agreement with those obtained by using the ICRP model for iodine. Committed equivalent dose to the thyroid gland is influenced by the mass of thyroid, 131 I uptake and energy of the emitted beta particles. In addition, 131 I uptake was measured by using a gamma camera and committed equivalent doses to the thyroid gland of female patients from the ingestion of 131 I for the treatment of hyperthyroidism diseases were evaluated. Data obtained by using our model and the ICRP ingestion dose coefficients are in good agreement with each other.

CR-39 and LR-115 type II solid state nuclear track detectors (SSNTDs) are both used, in order to assess the concentration of nucleus belonging to 238U and 232Th series, these ones can be also used to measure radon 222Rn and thoron 220Rn gases in different locations. In this paper, a Monte Carlo code was developed to calculate the mean critical angle for which alpha particles emitted from 238U and 232Th families in studied material samples reach CR-39 and LR-115 type II surfaces and bring about latent tracks on them. The dependence of the SSNTDs mean critical angle on the removed thickness, the initial alpha particle energy has been studied. A linear relationship between CR-39 mean critical angle and the initial alpha particle energy for different removed thicknesses has been found. This straightforward relationship allows determining quickly the mean critical angle of etching which corresponds to initial alpha particle energy for a given removed thickness. CR-39 mean critical angle ranged from 59° for an alpha particle emitted by 212Po to 71° for an alpha particle emitted by 232Th, for the value of removed thickness of 6 µm; whereas LR-115 type II mean critical angle does not depend on the initial alpha particle energy except for 232Th, 238U, 230Th and 234Ra when the removed thickness ranged from 6 µm to 8 µm. Obtained data by using the current method and those obtained in the literature [18] are in good agreement with each other.

Radioiodine 131I is successfully used in nuclear medicine for the treatment of hyperthyroidism and thyroid cancer. This radionuclide emits β− particles used for the treatment and gamma photons used for diagnosis. The aim of this study is to determine gamma radiation doses received by medical personnel situated at a distance of 1 m from patients having ingested 131I for the treatment of hyperthyroidism diseases. Indeed, gamma doses were calculated using a Monte Carlo code based on simulating the interaction processes of gamma photons emitted by 131I in the thyroid gland, air, and an ambient flow meter placed at a distance of 1 m from the thyroid gland to measure the administered 131I activity. The thyroid volume of patients was measured by means of a gamma camera. Gamma dose equivalent rates were measured by means of an ambient flow meter situated at a distance of 1 m from the thyroid of the treated patients. Data obtained by the Monte Carlo and experimental methods were found to be in good agreement with each other.

AbstractIn this work, we used CR-39 and LR-115 type II solid-state nuclear track detectors to measure 238U, 232Th,222Rn and 220Rn concentrations in Merzouga sand. The measured concentrations of 238U and 232Th in the studied sand samples vary from (332.59±16.62) mBq·cm−3 to (335.54±20.13) mBq·cm−3 and (80.43±4.02) mBq·cm−3 to (84.75±5.08) mBq·cm−3, respectively. We evaluated the radiation doses to the skin from the application of different sand baths by the patients by using a model based on specific alpha-dose and alpha-particle residual energy concepts. The maximum total equivalent dose to the skin due to the 238U and 232Th series from the cutaneous application of different sand baths by patients was found equal to (148.12±11.85) µSv y−1cm−2

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