Variabilities in chromosomal aberrations in human somatic cells

: Variabilities in the frequency of spontaneous chromosomal aberrations depend on subjective and objective factors, the stochastic nature of occurrence and recording of the aberrations. Due to the low frequency of spontaneous chromosomal aberrations, it is impossible to exactly assess their frequency on an individual basis. The low accuracy of estimating the individual frequency of spontaneous chromosomal aberrations while analyzing 100-1000 cells virtually allows the use of the individual average frequencies of chromosomal aberrations without taking into account the size of a sample to have an average group estimation of the frequency of chromosomal aberrations. The average frequencies of spontaneous chromosomal aberrations can be obtained to a rather high accuracy for individual groups when a sample comprises 50 to several hundreds of individuals. It is shown that the frequency of spontaneous chromosomal aberrations does not depend on sex and age. There is a significant variability in their frequency in relation to a season and to the year of a follow-up. Regular changes are found in the frequency of spontaneous chromosomal aberrations depending on the number of a month and on the year of a follow-up.