The effects of tritiated water on the bone marrow cells in mice.

Tritium RBE/Tritiated Water/CFUs/CFUc The acute effects on hematopoietic tissue in mice of a single administration of tritiated water were compared with the effects of exposure to 6OCo gamma radiation. The activity of tritium in the bone marrow was measured directly using a sample oxidizer and the absorbed dose was calculated from the amount of activity of tritium in it. The number of nucleated cells, colony forming unit-spleen (CFUs), colony forming unit-culture (CFUc), and fibroblastoid colony forming unit (CFUf) in bone marrow were determined to evaluate the effects of tritium and 60Co gamma radiation on bone marrow. The dose-response curves were derived from the observed data and the RBE values of tritium beta rays relative to 6OCo gamma rays were calculated to be 0.91, 1.09 and 1.51 for nucleated bone marrow cells, CFUs and CFUc, respectively, for 2 days exposure to HTO and 6OCo gamma radiation.