Induction of cell killing, mutation and oncogenic transformation following exposure to tritiated water in cultured mammalian cells

Induction of cell killing and mutation to 6-thioguanine resistance was studied in proliferating, cultured mouse leukaemia cells following their exposure to HTO, tritiated amino acids and low dose rate gamma rays. The combined effects of HTO and D2O were also studied. Tritium beta rays were found to have RBE values of 1.5 to 2.5 relative to gamma rays. No appreciable dose-response differences were found between HTO and tritiated amino acids per unit of absorbed dose. Studies with cultured, confluent 10T1/2 cells showed that tritium beta rays were more damaging than low dose rate gamma rays; RBE values between 1.5 and 1.8 were obtained using cell killing and cell transformation as endpoints. (author)