Myeloid leukemia 239Pu-treated mice.

Incidence of myeloid leukemia was studied in 79 mice injected i.v. with 180 kBq 239Pu/kg. Plutonium-treated mice were compared with 70 controls of the same origin and sex (random-bred ICR-SPF female mice). The animals were killed moribund and the disease was diagnosed on the basis of histological and cytologic examination of bone marrow, spleen, liver, peripheral blood, and other tissues. It has been found that 22 plutonium-treated mice (27.8%) and 17 controls (24.3%) were leukemic. The mean survival of diseased animals was 459 +/- 19 days in the tested group and 559 +/- 24 days in controls. It means that the occurrence of myeloid leukemia was not very different in irradiated and control mice, but under plutonium contamination the disease appeared significantly earlier and its incidence was shifted to the younger age.