DNA replication and repair in human cells exposed to thermal neutrons.

The degree of inhibition of DNA replication and the level of DNA repair synthesis induced by thermal neutron irradiation was determined in human lymphoblastoid cell lines. Dose response experiments revealed that, when compared with equivalent doses of 60Co-γ-irradiation, thermal neutrons gave rise to similar levels of inhibition of DNA replication but induced relatively low levels of DNA repair synthesis. The amount of repair synthesis after exposure of cells to thermal neutrons, was about ten-fold lower than that observed after γ-radiation. Reasons for this difference are discussed in terms of the type and incidence of damage induced by thermal neutrons.