[Comparative effectiveness in the induction of sister chromatid exchanges and chromosome aberrations]

The dose curves for 5 chemicals were studied to compare the efficiency of induction of SCEs and chromosomal aberrations by "polycentric" mutagens. The number of SCEs was found to increase linearly with the dose while that of chromosomal aberrations--nonlinearly. The efficiency of SCEs induction by these mutagens was found to be 25-50 times as high as in the induction of chromosomal aberrations. Division of alkylating mutagens into "monocentric" and "polycentric" is shown to be useful. It reflects their different efficiency in damaging one or simultaneously two DNA strands. The correlation between SCEs and formation of aberrations of the chromatid type is stated.