[Risk of radiation exposure and internal medicine]

The paper informs in concise form about the risk which consists in the medical application of the ionizing radiation for physician and patient. In the introduction a short retrospective view on the development of the knowledge of the various radiation injuries is given. Following this is shown which international activities concerning the limitation of the radiation risk are to be registered in view of the world-wide increase of the nuclear and radiation technology. The principle of radiation protection is explained by giving limit values in order to exclude non-stochastic radiation injuries and to limit stochastic injuries to a measure worth being advocated for persons exposed to radiation. The importance of the risk calculation necessary for the derivation of limit values is explained and thereby is referred to the open problems in connection with the dose-effect relations for certain radiation effects. Finally in the light of two examples the actually presumable risk for the physician and his staff and for the patient is demonstrated which altogether is to be classified as extremely low.