On the distributions of spontaneous chromosomal aberrations in human peripheral blood lymphocytes in culture

It has long been established that radiation-induced chromosomal aberrations are distributed among cells essentially according to the Poisson distribution, at least for low doses. In fact, the distributions tend to be underdistributed (i.e., variance smaller than the mean) at high doses for exchange-type aberrations, owing to the limitation imposed by there being only a finite number of chromosomes available to participate. Also, at low doses the distributions often tend to be a bit overdistributed (i.e., variance somewhat larger than the mean) for low linear-energy transfer (LET) radiations, and, naturally, quite markedly overdistributed when the aberration inducer is radiation of high LET. (DBO)