[Cytogenetic effect of small doses of tritium beta irradiation].

The effect of tritium beta-radiation within the dose range of 0.5 x 10(-3) = 0.6 Gy on human blood lymphocytes in vitro was investigated. Dose-effect correlation was determined by the frequency of aberrant cells and the sum of chromosome aberrations per 100 cells. As compared to a rated curve corresponding to a linear-quadratic model y = a + bD + cD2, experimental curves (showing correlation between cytogenetic indices and a dose) are of abnormal nature with a plateau in a dose range less than 7.5 x 10(-2) Gy. A big confidence interval of cytogenetic effect indices in a dose range less than 7.5 x 10(-2) Gy was shown to be determined by the number of analyzed metaphases. The proof of significance of a plateau on a dose-effect curve in regions of small doses (e.g. with a confidence interval of +/- 24%) necessitated analysis of no less than 10,000 metaphases per dose.