Cytogenetic analysis in human lymphocytes after exposure to simulated cosmic radiation which reflects the inflight radiation environment.
OBJECTIVE
To determine the relative biological effectiveness (RBE) of a mixed neutron-gamma-radiation field and its high LET component on the induction of chromosome aberrations in human lymphocytes.


METHODS
Human lymphocyte cultures were exposed in vitro to low doses of simulated cosmic radiation (2.39-5.81 mGy) at low dose rates (0.04-0.15 mGy/h). Chromosome aberrations, micronuclei, and sister chromatid exchanges (SCE) were analysed. The RBE for dicentric chromosomes was given in comparison to 60Co gamma-rays.


RESULTS
For the induction of dicentric chromosomes by simulated cosmic radiation the RBE was up to 64, and up to 113 when calculating only the high LET component. The investigation of micronuclei and SCE showed no significant differences between controls and irradiated samples.


CONCLUSIONS
Preliminary data indicate a high biological effectiveness of cosmic radiation and its neutron component in comparison with 60Co gamma-radiation.
Heimers
A
A
Department of Physics, University of Bremen, Germany. agmed@physik.uni-bremen.de
D000337:Aerospace Medicine; D002478:Cells, Cultured; D002869:Chromosome Aberrations; D003359:Cosmic Radiation / Q000009:adverse effects*; D004307:Dose-Response Relationship, Radiation; D005260:Female; D005720:Gamma Rays; D006801:Humans; D008214:Lymphocytes / Q000528:radiation effects* / Q000648:ultrastructure; D048629:Micronuclei, Chromosome-Defective / Q000528:radiation effects; D009502:Neutrons; D016273:Occupational Exposure; D012062:Relative Biological Effectiveness; D012854:Sister Chromatid Exchange / Q000528:radiation effects