More Precise Determination of the Relative Biological Effectiveness of Fast Neutrons and Accelerated Multi-Charged Ions at Low Doses for Estimation of the Risk of Injury of Brain and Lens Neurons

Abstract

The authors review the available data on damage to cortical neurons and incipient lenticular opacity in small laboratory animals after exposure to fast neutrons, accelerated multi-charged ions (AMCIs), and different doses of X- and γ-rays. Analysis and possible revision of maximum coefficients of relative biological effectiveness (RBEM) for these effects, as well as RBEM coefficients for other space radiation-induced impacts, including blast transformation, cytogenetic alterations, increased probability of tumor development in organs and tissues, and reduction in estimated life expectancy, will lay the grounds for reconsideration of the existing normative documents and calculations of generalized and equivalent doses for organs and tissues based on the absorbed dose values. At present, Russian GOST 25 645.218-90 “Space Crew Radiation Safety during Space Fight” and recommendations of the International Commission on Radiological Protection (ICRP, papers 60 and 61, 1994) reflect the dependence of space radiation quality factors (QFs) on linear energy transfer.