effects of radionuclides were performed. occupational safety. The impetus for this work wes In addition, some medical work was also being done. In the 1950s and 1960s, the awareness of radioactive fallout changed the purpose of much work to addressing public safety. Much of the work was environmental tn nature, which evolved into the discipline of radioecology. The first symposium on radionuclides in the environment was held in 1959 (Caldecott and Snyder, 1960), closely followed by a symposium on radtoecology held in 1961 (Schultz and Kiement, 1963). In the 1960s and up to the present, work has contimed related to the public safety from internal emitters, though the driving force evolved fran contamination by nuclear weapons to the potential for contamination by nuclear reactors and related fuel cycle operations. problems of occupational exposure. Work also continued to address . Unlike the research of the 1940s, which ee tended to emphasize immediate effects of high levels of exposure, the more contenporary work has emphasized the consequences of long-term exposures and latent health effects of low level exposures as well as the mechanisms of these effects. Radiation-induced cancer has been the significant end-point of t - most of the more recent research.