Biological aspects of radiation protection

On March 21, 2007, in Essen (Germany) the new basic Recommendations for protection of man and environment from ionizing radiation issued by the International Commission on Radiological Protection (ICRP) were approved. In working out the Recommendations the ICRP took into account new biological and physical information, as well as the key trends in the development of radiation safety standards. A major reason for the revision of the Recommendations was the complexity of the old radiation protection system. The new Recommendations are focused on the further development of the fundamentals of the 1977 Recommendations (ICRP Publication 26) and the 1990 Recommendations (ICRP Publication 26): the principles of rightfulness, optimization and restrictions. Persons responsible for radiation protection are obliged to quantitatively commensurate risks and establish the optimum balance of risks and benefits. Thus, although the main focus of the new Recommendations is on protection of individuals from radiation sources, it would be necessary to optimize the protection in order to achieve its maximum effectiveness under any concrete circumstances. Responsibility for optimization is imposed on the respective national organizations. In addition to the main document of the Recommendations, documents on substantiation of effects of small doses and relative biological effectiveness of radiation were created which allowed revisions of weighting factors for different tissues and types of radiation. The key ideological principle the ICRP applied in the preparation of the new radiation safety system was the motto precedence to continuity rather than to changes.