Organ doses from environmental exposures calculated using the ICRP Reference Male and Reference Female voxel phantoms

In its recent recommendations the ICRP adopted two voxel models of an adult male and an adult female to be used for the forthcoming update of organ dose conversion coefficients. These voxel models are representative of an average population, i.e. they resemble the ICRP reference anatomical data with respect to their external dimensions and their organ masses and were constructed for this purpose. They will be used as the standard human models for the computation of dose conversion coefficients in occupational protection as well as for the protection of the patient and the general public. Using these new models, conversion coefficients for environmental exposures were computed. Two source geometries were simulated, exposure from a radioactive cloud and from ground contamination, by taking into account the precise angular and energy distributions of the gamma rays. The organ dose conversion coefficients were calculated using the Monte Carlo code EGSnrc simulating the photon transport in the voxel models. Furthermore, new nuclear decay data have been released by the ICRP. These have been used in order to calculate dose equivalent rates for photon exposures of several radionuclides for the above environmental exposures.