Modeling the Depressed Hematopoietic Cells for Immune System under Chronic Radiation

Although moderate dose (0.5 to 2 Gy) of ionizing radiation (IR) is well recognized to cause various disorders of the hematopoietic system (e.g., short-term effects like cytopenia, and long-term effects like leukemia), many quantitative aspects of the dynamics of the hematopoiesis response to long duration low dose rate IR still require additional investigation. Recently two cell kinetics models after acute radiation exposure are proposed to describe the perturbation of granulocytes and lymphocytes, respectively, in peripheral blood of various mammals. These two models are indeed built on a similar coarse-grained structure of hematopoietic system, thus they have the potential to form a unified model to characterize the mammalian hematopoietic system after various types of IR exposure. In this study we investigate the capability of the models to simulate the data of hematological measurements of the Techa River residents chronically exposed to IR in 1950-1956. Our modeling investigation indicates human hematopoietic precursor cells are more sensitive to chronic radiation than previously considered.