[Cytogenetic effects induced by neutrons in human peripheral blood lymphocytes in vitro. I. Dose-effect relationship for different types of chromosome aberrations when exposed to neutrons with different energies].

Human lymphocytes were irradiated in vitro during G0 stage by graded doses of thermal neutrons and of neutrons with mean energy of 0.04; 0.09; 0.35; 0.85 and 14.7 MeV as well as by 60Co gamma-rays. The data were fitted to the linear and linear-quadratic relations. The neutrons of low and intermediate energies showed the linear dependence on the dose, 14.7 MeV neutrons and gamma-rays--a linear-quadratic one, whereas the data obtained with 0.85 MeV neutrons fitted well the both models. Terminal and interstitial deletions produced by both gamma-rays and neutrons showed different dependencies upon the dose. Some qualitative pecularities of aberration spectra were found in the experiments with neutrons as compared with the data on gamma-irradiation: the ratio of exchanges to fragments was greater, and aberrations of chromatid type were produced. The specially designed experiments and calculations showed that the last effect was not connected with induced radioactivity.