An experimental study of fission neutron carcinogenesis

We previously investigated the dose-effect relationship for lung carcinomas in rats exposed to radon and daughters at doses ranging from 20 to 12,000 working-level months (WLM). For comparison of the carcinogenic effectiveness of neutrons, rats of the same strains were given doses from 0.01 to 8 Gy, and the dose-effect relationship was estimated for the same lung carcinomas. Other malignant and benign tumors from various organs were analyzed by using a classification similar to that used for man. The data obtained make it possible to relate frequency and time of observation to radiation dose for each type of cancer. The dose-effect relationship for the various types of radiation-induced cancers differs. The relative radiosensitivity of organs is therefore also apparently dose dependent. If effects from radon are taken as a reference, the carcinogenic effectiveness of neutrons in rats is higher than is reflected by the quality factor currently used for man. 7 refs., 8 tabs