Radiation risk and radiological protection

With respect to radioactive waste health risks are caused by ionising radiations which occur in conjunction with the decay of radionuclides. Biological risks of ionising radiation were already identified a few years after the discovery of X-rays by Rontgen (1895) and of radioactivity by Becquerel (1896). A very extensive knowledge has been achieved about estimating radiation doses (see section B 2.2) and radiation effects by clinical studies as well as by experimental investigations. For risk evaluations, the shape of the dose effect curves is of eminent significance (Fig. B.29). In radiation research as well as in toxicology of chemicals in general two principal categories of dose effect relationships have been described (ICRP 1977). The shape of these dose response curves is based on manifold experimental studies of radiation effects which have been experimentally investigated by studying molecular structures, living cells and animals after radiation exposures. Further data have been obtained from clinical experiences and epidemiological studies which have been observed after the exposure to ionising radiation in humans in connection with radiotherapy, diagnostics, atomic bomb explosions in Japan and further accidents (UNSCEAR 1993; 1994; 2000; 2006 BEIR 1990; 2005).