Microdosimetric Interpretation of the Dose and Dose Rate Efficiency Coefficient

Resumo

A model of a hypothetical process resulting in damage to DNA by ionizing radiation, as a result of which a nonlinear dose dependence of carcinogensis can form at dose 10–100 mGy, is examined on the basis of a microdosimetric approach. The model assumes that the primary damage to DNA interacts with short-lived products of irradiation before the DNA is repaired or transformed into a precancerous defect that is transferred to a daughter cell. It is shown that there are grounds for using the ICRP effective dose and dose rate lowering coefficient equal to 2 in the evaluation of the lifetime risk of irradiation with a significant dose and in the validation of criteria for radiation safety on the basis of data on morbidity and mortality in a cohort of Japanese atomic bomb survivors.