TY - JOUR
T1 - Cytogenetic damage analysis in mice chronically exposed to low-dose internal tritium beta-particle radiation
AU - Roch-Lefèvre, Sandrine
AU - Grégoire, Eric
AU - Martin-Bodiot, Cécile
AU - Flegal, Matthew
AU - Fréneau, Amélie
AU - Blimkie, Melinda
AU - Bannister, Laura
AU - Wyatt, Heather
AU - Barquinero, Joan Francesc
AU - Roy, Laurence
AU - Benadjaoud, Mohamed
AU - Priest, Nick
AU - Jourdain, Jean René
AU - Klokov, Dmitry
PY - 2018/6/1
Y1 - 2018/6/1
N2 - © Roch-Lefèvre et al. The aim of this study was to carry out a comprehensive examination of potential genotoxic effects of low doses of tritium delivered chronically to mice and to compare these effects to the ones resulting from equivalent doses of gamma-irradiation. Mice were chronically exposed for one or eight months to either tritiated water (HTO) or organically bound tritium (OBT) in drinking water at concentrations of 10 kBq/L, 1 MBq/L or 20 MBq/L. Dose rates of internal β-particle resulting from such tritium treatments were calculated and matching external gamma-exposures were carried out. We measured cytogenetic damage in bone marrow and in peripheral blood lymphocytes (PBLs) and the cumulative tritium doses (0.009 - 181 mGy) were used to evaluate the dose-response of OBT in PBLs, as well as its relative biological effectiveness (RBE). Neither tritium, nor gamma exposures produced genotoxic effects in bone marrow. However, significant increases in chromosome damage rates in PBLs were found as a result of chronic OBT exposures at 1 and 20 M Bq/L, but not at 10 kBq/L. When compared to an external acute gamma-exposure ex vivo, the RBE of OBT for chromosome aberrations induction was evaluated to be significantly higher than 1 at cumulative tritium doses below 10 mGy. Although found non-existent at 10 kBq/L (the WHO limit), the genotoxic potential of low doses of tritium ( > 10 kBq/L), mainly OBT, may be higher than currently assumed.
AB - © Roch-Lefèvre et al. The aim of this study was to carry out a comprehensive examination of potential genotoxic effects of low doses of tritium delivered chronically to mice and to compare these effects to the ones resulting from equivalent doses of gamma-irradiation. Mice were chronically exposed for one or eight months to either tritiated water (HTO) or organically bound tritium (OBT) in drinking water at concentrations of 10 kBq/L, 1 MBq/L or 20 MBq/L. Dose rates of internal β-particle resulting from such tritium treatments were calculated and matching external gamma-exposures were carried out. We measured cytogenetic damage in bone marrow and in peripheral blood lymphocytes (PBLs) and the cumulative tritium doses (0.009 - 181 mGy) were used to evaluate the dose-response of OBT in PBLs, as well as its relative biological effectiveness (RBE). Neither tritium, nor gamma exposures produced genotoxic effects in bone marrow. However, significant increases in chromosome damage rates in PBLs were found as a result of chronic OBT exposures at 1 and 20 M Bq/L, but not at 10 kBq/L. When compared to an external acute gamma-exposure ex vivo, the RBE of OBT for chromosome aberrations induction was evaluated to be significantly higher than 1 at cumulative tritium doses below 10 mGy. Although found non-existent at 10 kBq/L (the WHO limit), the genotoxic potential of low doses of tritium ( > 10 kBq/L), mainly OBT, may be higher than currently assumed.
KW - Chronicle
KW - Genotoxicity
KW - Low-dose
KW - Tritium exposure
U2 - 10.18632/oncotarget.25282
DO - 10.18632/oncotarget.25282
M3 - Article
SN - 1949-2553
VL - 9
SP - 27397
EP - 27411
JO - Oncotarget
JF - Oncotarget
IS - 44
ER -