Cs 137 dose measurements in tissue--II.

Abstract

The silver phosphate glass dosimetry system was used to measure the beta and gamma radiation dose from Cs/sup 137/ to the testicles, muscle, liver, and kidneys of dogs. The size of the dosimeter rods (1 x 6 mm) permitted surgical placement within the tissues, and use of lucite shields allowed measurement and comparison of the beta and gamma exposure relationships from known amounts of the ingested Tadioactivity. Two groups of dogs were used in the in vivo experiments. One group was given a single meal of Cs/sup 137/ and killed after 28 days. The second group was given the radioactivlty daily for a 56-day period. Blood and muscle blopsles were taken for determination of radioactive concentratlons throughout the exposure periods, and extensive tissue sampling was done at autopsy. The beta -dose to muscle, when calculated from concentration- time data, compared favorably with that measured with dosimeters. It was estimated that gonads would receive a radiation dose of 0.05 to 0.10 rad/ mu c Cs/ sup 137/ ingested when calculated with an exposure time of 1 year. No difference in the delivered radiation dose per microcurie ingested was observed between the two groups. Extrapolation of the dog data to man wasmore » made. It is calcuated from the data that an intake of 80- 160 mu c Cs/sup 137/ would deliver the maximum permissible dose (MPD) of 5 rads/ year. This range spans the 110- 160 mu c Cs/ sup 137/ estimate for standard man computed from NBS Handbook 69 values. (auth)« less