WILD DEER AS A SOURCE OF RADIONUCLIDE INTAKE BY HUMANS AND AS INDICATORS OF FALLOUT HAZARDS.

Concentrations of various fallout radionuclides were measured in native forage and in tissues of wild mule deer over a five-year period in north-central Colorado. Concentrations of 137 Cs in deer flesh were 5 to 13 times higher than concentrations reported in beef and in pork. The data indicated that consumption of deer flesh could result in a 137 Cs intake which could possibly exceed the intake of the nuclide from all other items of the total diet combined. Consumption of deer liver would result in the ingestion of 144 Ce, 137 Cs, 54 Mn, and 106 Ru. The data indicated that deer tissues can be useful and in some cases, unusually sensitive indicators of environmental contamination by 144 Ce, 137 Cs, 131 I, 54 Mn, 106 Ru, and 90 Sr. Relationships between forage and deer tissue for 137 Cs, 131 I, and 90 Sr were investigated. During 1963, the radiation dose to the skeleton of yearling deer from 90 Sr averaged 330 mrad, which was generally higher than the total dose from natural background and other sources combined. During the same period, the 90 Sr concentrations in deer bone were higher by a factor of 35 than reported bone levels in humans. During the study, dose rates to deer thyroid, liver, and muscle reached 20, 0.014, and 0.012 rad/year, respectively.