Aspects of the dosimetry of alpha-emitting radionuclides in bone with particular emphasis on 226Ra and 239Pu.

The dosimetry of alpha-emitting radionuclides in bone is discussed. Results are presented for average dose rates to tissues close to endosteal surfaces and to haematopoietic bone marrow from thin plane sources of radionuclides buried to different depths in bone and emitting alpha-particles with energies in the range 3-8 MeV. These results are used to demonstrate that on an activity basis 239Pu is unlikely to be more than fifteen times as toxic as 226Ra with respect to osteosarcoma and leukaemia induction in man.