Chromosomal aberrations in healthy persons.

The frequency of chromosomal aberrations was studied in peripheral blood lymphocytes obtained from 175 healthy individuals of both sexes between 18 and 45 years of age. No aberrations were detected in 113 individuals, but a total of 154 aberrations was found in lymphocytes from 62 persons. The chromosomal aberrations occurred with frequencies between 1 and 6% per cell. These anomalies appeared as 80 chromatid breaks, 62 chromosome fragments and 12 dicentrics, giving an average of 0.88% aberrations per person. This value may be considered as the spontaneous level of aberration frequency in a normal population and may serve as a reference for the evaluation of those occupationally exposed to radiation.