Time variations in radiation-induced relative risk and implications for population cancer risks

The Armitage-Doll and Moolgavkar-Venzon-Knudson models of carcinogenesis have been examined and shown to predict a reduction in relative risk with time following the administration of a single instantaneous dose of radiation. The magnitudes of the reduction in relative risk that each model predicts are compared. The Japanese bomb survivors and 12 other cohorts have been analysed and provide evidence for a reduction in the radiation-induced relative risk of cancers (other than leukaemia) with time following exposure. (author)