Assessment of absorbed dose in the hematopoietic stem cell layer of the bone marrow, assuming non-uniform distribution around the vascular endothelium of the bone marrow

Recent studies have shown that hematopoietic stem cells (HSCs) are concentrated around the endothelium of the sinusoidal capillaries. However, the current International Commission on Radiological Protection (ICRP) dosimetry model does not take into account the heterogeneity of the bone marrow tissue and stem cell distribution. In this study, the absorbed doses to the stem cell layer in the perivascular HSC layer in the bone marrow from radionuclides inhaled into the body were estimated for the major beta- and alpha-nuclides and noble gases and compared with the absorbed dose based on the ICRP 60 and ICRP 103 recommendations. The absorbed doses to the bone marrow obtained from the model calculations were not significantly different from ICRP60 and ICRP103 for beta-nuclides but were much lower than previously estimated for alpha-nuclides, and the contribution of red bone marrow and blood sources was greater than that of trabecular bone for alpha-nuclides. Noble gases in the red bone marrow may also affect the bone marrow stem cell layer. The bone marrow dose assessment for alpha nuclides and noble gases should be re-examined using a precise model based on CT images from the perspective of occupational and public radiation protection.