Chromosomal mutations by low dose radiation vs. those by other mutagenic factors

In order to estimate the genotoxic risk due to low dose radiation, it is essential to distinguish the effect of radiation from those of chemicals. In this presentation, the difference between radiation-induced chromosomal aberrations and those induced by chemical mutagens, and the characteristics of dicentrics and translocations are described. Then, the significance of the chromosome aberrations in the normal living circumstances is discussed. It is shown that dicentrics and translocations are very sensitive and useful biomarkers in the study of the effect of low dose radiation in comparison with the effect of other clastogens. It is suggested that any effect of radiation such as malignant diseases attributable to the alteration of DNA would not be revealed by the epidemiological study at the excess dose level of 20 cSv in the normal living circumstances.