Room: AAPM ePoster Library
Purpose: Red bone marrow (RBM) doses for clean-up workers, who took part in decontamination activities after the accident on Chernobyl nuclear power plant were previously estimated using the Realistic Analytical Dose Reconstruction with Uncertainty Estimation (RADRUE) method to support an epidemiologic study on leukemia risk. The current study was intended to evaluate the impact of body weight of the workers on red bone marrow dose.
Methods: The cohort consisted of 137 cases of leukemia with 863 workers in control group. Air kerma for each individual was extracted from the dosimetry database. Three versions of RBM doses were calculated from three different sets of RBM dose conversion coefficients (CCs): the original CCs from the ICRP Publication 74; the recent CCs based on realistic computational human phantoms from ICRP Publication 116 and body size-dependent CCs (Lee, 2016). The calculation was carried out by means of 10,000 stochastic simulations. The CC was presented as normal distribution, the mean value and standard deviation was used for certain energies and irradiation types.
Results: RBM doses were calculated for AP, ROT and ISO exposure situations for photon energy range 0.15-0.4 MeV. The results with the body size-dependent CC coincide with the RARRUE results within the uncertainty. Individual RBM dose estimates were found in range 3.9·10?8 – 3.4 Gy with a mean of 124 mGy, average geometric standard deviation is 2.0.
Conclusions: For the same irradiation situation for workers with body mass 110 kg the mean RBM dose is 20% lower than for 60 kg. For the AP irradiation geometry for 60 kg body weight the mean dose is 33% higher than the mean dose in RADRUE, therefore for this kind of worker an underestimation of the RBM dose is possible. The difference in CCs will be significant while reducing other uncertainties of the RADRUE method.