Radiation-induced Chromosome Aberrations in Radiological Protection Dose–response Curves at Low Dose–levels

Abstract

The total number of dicentrics, centric rings and acentrics together with the number of dicentrics and acentrics per cell were studied in human lymphocytes exposed to X-radiation. The results were analyzed on linear and quadratic dose response models. When computed from the difference between the observed and expected frequencies of aberrations, the frequency of dicentrics was a good fit to a linear dose-response model but the frequency of acentrics was not a good fit. The acentric yield was higher than the dicentric yield up to 60 rad but at higher doses the dicentrics predominate. Because they are less variable the dicentrics seemed to provide a more accurate measurement of the dose even at low dose levels. The dicentric and acentric yields plotted against the dose can be fitted with a straight line. The x2 test showed that the agreement between observed and expected frequencies is significant only for the dicentrics while it showed a significant discrepancy for the acentrics.