A Comparison of the Effectiveness of Radiations of Different Energies in Producing Chromosome Breaks

Some of the effects of ionizing radiations on chromosomes can be detected at the first mitosis after a treatment. By cytological examination of radiation-treated chromosomes it is possible to determine the frequencies of persisting chromosome breaks and of other induced aberrations. The experimental results reported by many investigators indicate that with any ionizing radiation of particular energy the frequency of chromosome breaks is directly proportional to the radiation dose. Chromosome breakage is probably not produced directly by ionization within the chromosome. More likely the ionizations initiate a series of chemical and biochemical events which result in the appearance of breaks. It has been suggested (see, e.g., Gray, 1, for review) that peroxides formed as a result of ionization may interact with molecules of chromosomes in ways that will eventually result in visible breaks.