TITLE:
Cytogenetic Effects of Low-Dose Tritiated Water in Human Peripheral Blood Lymphocytes—Experimental Studies on the Relative Biological Effectiveness and Chromosome Aberration Rate and CBMN in Human Blood Lymphocyte Irradiated by Tritium Low Dose Tritium β-Rays and 60Co γ-Rays
AUTHORS:
Bing Deng, Jingwei Hou, Yi Quan, Lan Dong, Zhaoyi Tan
KEYWORDS:
Tritium, β-Radiation, Chromosome Aberrations, MN, RBE
JOURNAL NAME:
Open Journal of Clinical Diagnostics,
Vol.5 No.4,
October
28,
2015
ABSTRACT: In this study, the yields of unstable chromosome aberrations in human lymphocytes induced by β particles from low-dose HTO have been measured. HTO was mixed with heparinized blood in varying amounts so that a dose of 6.24 × 10－4 Gy to 1.23 Gy were delivered in 24 and 48 h, respectively. After 72-h culture, the dicentric yield was measured as a function of dose to the blood and compared with data from 60Co γ-radiation. Using a linear-quadratic dose-effect relation to fit the experimental data, a significant linear contribution Y = 0.062D + 0.053D2 was found. The main difference between the coefficients for β and γ-radiation was in the a values, indicating that HTO β-rays were more efficient, particularly at low doses. As per the theory of dual radiation, the relative biological effectiveness (RBE) of HTO β-particles relative to γ-rays is 2.21 at 0.06 Gy and decreases with increasing dose. Micronucleus yield at low doses was fitted to a linear equation Y = C + αD, indicating that the RBE value of MN for HTO β-rays irradiation was between 1.46 and 2.17, which is similar in shape to the chromosome aberrations experiments. Thus, β-rays were found to be more efficient in producing two lesions with single ionizing tracks at low dose.