Analysis on the basic processes of biological radiation effects as probed by low-energy radiations

The induction of chromosome aberrations was studied in human lymphocytes irradiated with monochromatic soft X-rays with quantum energy between 1.9 keV and 14.6 keV and fission neutrons with different energy spectra. The analysis of dose-response curves led us to a 'distance model', in which chromosome exchange aberration does arise as a consequence of pairwise interaction of DNA damages. While DNA is the prime target, the spatial proximity of the elemental chromatin fibers as vehicles of damage fixation as well as particle range rather than LET are of significant importance as the measure of biological radiation effects. (author)