Modelling the peripheral blood count dynamics in workers externally exposed to ionizing radiation during prolonged periods

The aim of the study was to model the dynamics of the peripheral blood count (platelets) in Russian nuclear workers chronically exposed to external gamma rays. Workers were divided in three groups depending on the total dose absorbed in bone marrow: <1.0 Gy, 1.0 to 2.0 Gy, ≥2.0 Gy. Factors such as the total dose, dose rate and duration of employment were considered as determinants of the platelet count dynamics. A dynamic regression model revealed statistically significant dose–response relationship in all study groups, while, in contrast, the analytical model fitted the data well only in the third group. The proposed method allows for the quantitative assessment of the time-dependent changes in the parameters of the peripheral blood relative to the individual initial level. This is critically important in case of chronic occupational exposure when cumulative dose increases with the increase in the duration of work with the ionizing radiation sources.