LEUKEMOGENIC EFFECT OF RADIOACTIVE PHOSPHORUS IN ADULT AND FETALLY EXPOSED BALB MICE.

Summary The leukemogenic effect of radioactive phosphorus has been studied in adult females and fetally exposed males and females of the BALB strain of mice. The results obtained in this series of experiments indicate that fetally exposed females are more sensitive to the effect of the agent than males (46.5 and 10.8 per cent, respectively). It has been observed that the incidence of leukemia in fetally exposed females is negatively correlated with the dose. In males, on the other hand, there is no such correlation and the over-all incidence is not increased (10.8 per cent). Adult and fetally exposed females submitted to sterilizing doses of P 32 show the same incidence of leukemias (42 and 36.3 per cent, respectively). The experiments herein reported demonstrate that P 32 is definitely leukemogenic.