Abstract
Following the 10th International Congress of Radiation Research held in Wu rzburg, Germany, in August 1995, around 100 scientists assembled in order to discuss one of the most urgent topics in radioprotection, namely what are the risks of exposure by ionizing radiations to man in the same low dose range as these exposures occur in the working place, in the environment, and through natural radiation sources. There is no doubt that carcinogenesis is the most important effect under these aspects. Epidemiological studies have generally shown a significant increase of this effect after exposures in the dose range 100 mSv. However, for lower radiation doses epidemiological studies do not give an answer to the questions if a threshold dose exists and whether the doseeffect curve is linear. It is therefore necessary to improve knowledge about the mechanisms of the biological effects of ionizing radiations.