Animal Investigation Program 1973 annual report: Nevada Test Site and vicinity

Data are presented from the radioanalysis of tissues collected from cattle, deer, desert bighorn sheep, and other wildlife that resided on or near the Nevada Test Site during 1973. Routine activities and special investigations are discussed. Iodine-131 was detected in the thyroid of a Nevada Test Site mule deer. The postulated source was worldwide fallout from a nuclear detonation conducted by the People's Republic of China. Other than the naturally occurring potassium-40, cesium-137 was the only gamma-emitting radionuclide detected with any consistency in soft tissues. Nine muscle samples from the Nevada Test Site beef herd contained levels of cesium-137 ranging from 14 to 50 pCi/kilogram. Muscle from two deer contained 20 and 30 pCi/kilogram. Rabbit muscle contained 200 pCi/kilogram and muscle from a feral horse contained 40 pCi/kilogram. Tritium levels in all animal tissues sampled were at background except for animals residing at the Area 15 farm and for a feral horse. Postulated sources of these exposures are discussed. The strontium content in bones continued the downward trend observed during recent years