Data on patients exposed to radioactive materials are being put on punched cards for a central catalog of cases. Over 800 cases of expcsure to radium, mesothorium, or their decay products have been located on which some details are available. Over 200 persons with occupational or therapeutic exposure to radioactive materials more » were located. Semiquantitative radium burden estimates were made on 32 individuals by means of breath samples. Assays of whole-body gamma emission due to radium burdens were made in the controlled background facility. The study of radium and mesothorium toxicity in human beings was continued, with emphasis on living persons as distinct from persons no longer living whose dosimetry is reconstructed from bone or tooth samples. The result is in substantial agreement with the half-periods already reported in the literature.
The half-period of thorium-232 was redetermined as 1.41 x 10/sup 10/ years. A list is included of publications during the period. Test results are also reported for an instrument designed for storing data in coded form on a magnetic tape loop for later transfer to an analyzer. A scintillation-type fast neutron dosimeter based on the Bragg-Gray cavity principle was tested for absolute dose measurements using a Pu-Be neutron source and 2.5 and 14-Mev monoenergetic neutrons obtained from d-d and d-t reactions. Results are summarized from dosimetry measurements, the development of radiation detection instruments and techniques, and miscellaneous related projects.
#Radium calm radio plus#
Measurements on the halflife of Ra/sup 228/ gave a result of 5.7 plus or minus 0.2 years. Whole-body radioactivity measurements weremade on 45 normal employees. Data are being recorded on punched cards for correlation with the incidence of various affects such as tumors, bone fractures, age at exposure, age at occurrence of effects, and other epidemicological conclusions. Comparison of results with data on Ra/Ca ratios of teeth and total skeleton and with data from whole-body measurements on the same individuals led to the conclusion that estimates of total skeleton Ra burden can be made with reasonable accurateness on the basis of data obtained from Ra gamma -counting a single tooth. Complete measurements were made of tooth and bone MsTh/Ra ratios on 24 individuals. An extensive intercomparison of Ra burden measurements on living subjects was carried out between more » M.I.T. In all cases possible gamma ray measurements were made of Ra and MsTh decay products retained in the body, alpha -ray measurements of Rn and Rn/sup 220/ in breath, a complete medical history was taken, a complete x-ray examination was made of the skeleton, and urinalysis, hematological, and blood chemistry studies were made. Physical and clinical studies were made on 151 persons. Several Thorotrast cases were also examined. The study of the toxicity of Ra and MsTh(Ra/sup 228/) in humans was continued. A list is included of publications during the period covered by this report. Several complementary inspection techniques were developed that appear capable of serving as reliable locators of recent underground explosions. Preliminary results are presented from studies of underground Rn concentrations as related to meteorological variables and the effects of underground explosions on Ra and Tn concentrations in soil gas. Investigations were continued on the behavior of Rn in the interstices of the soil. An attempt failed to remove Thorotrast from a patient by the use of the chelating agent, diethylenetriaminepentaacetic acid. The half-life of Cs/sup 132/ was found to be 6.53 plus or minus 0.03 days by the counting method used. The Cs/sup 137/ more » levels in normal subjects and Cs/sup 132/ levels in persons with tracer doses were determined by whole-body counting.
Data are presented on case histories and body burdens of Ra, MsTh, and Thorotrast in luminous dial painters and miscellaneous cases. The relative uptake of Ac and Th by the intestine was measured. The feasibility of thicksource alpha spectroscopy, using solid state detectors, for the analysis of bones containing Ra and MsTh was investigated. Measurements were carried out to check the reproducibility of the whole-body counting methods and to investigate scanning techniques. Studies were continued on the toxicity of Ra and MsTh in human beings having body burdens of about 0.02 mu c Ra or the equivalent.
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