Assessment of risks and dose thresholds for some effects of acute exposure.

Findings from the analyses of the dose-response relationship are reviewed with regard to different effects of acute radiation exposure. The analyses have been performed based on the dosimetry and clinical data for the nuclear workers acutely exposed to gamma rays or gamma rays and neutrons as a result of radiation accidents at the Mayak Production Association (Russia). The statistically significant risk curves for morbidity and mortality from acute radiation syndrome (ARS), as well as risks of the onset of vomiting at the prodromal phase and agranulocytosis, have been obtained. The Weibull model appropriately describes the corresponding risk curves. Estimates of the dose thresholds have been obtained for ARS morbidity (∼0.7 Gy) and mortality (∼6-7 Gy), vomiting at the prodromal phase (∼1.5 Gy), and agranulocytosis (∼3.5 Gy). The statistically significant power dependence between the onset of vomiting at the prodromal phase and the onset of agranulocytosis, as well as the dose dependence for the onset of agranulocytosis, has been revealed.