Biological Dosimetry Technique for Estimation of Doses from Accidental Exposure to External γ-Rays.

Individual doses from external γ-rays were estimated using biological dosimetry based on limited samplings (n₁= 15 and n₂ 12 individuals) which comprised the Mayak workers group with acute radiation sickness (ARS). The following primary data were used for calculation as initial parameters: estimated dose from ex- ternal γ-rays based on physical dosimetry methods - D (Gy); time before first vomiting - T (h); number of lymphocytes in peripheral blood on a second day after acute radiation exposure - L (10⁹/1); number of neutrophils in blood during first hours after accidental radiation exposure - N(10⁹/). A number of mathe- matical models used for dose estimation were verified: power-law dependence of the absorbed dose from ex- ternal γ-rays (D) on time before first vomiting (7), exponential dependence of D on the number of lympho- cytes in peripheral blood (L), dependence of D on the number of neutrophils in peripheral blood (N) and complex models forD association with Tand L parameters as well as-with Tand Nparameters. The biological dosimetry technique based on a complex approach was shown to provide the best agreement with physical dosimetry methods for individual assessment of doses from external γ-rays.