Radiation Protection in Canada: Part III. * The Role of the Radiation Protection Division in Safeguarding the Health of the Public

The current status of radiation protection in Canada is discussed in the last of a three-part series. Particular emphasis has been placed on the role of the Radiation Protection Division of the Department of National Health and Welfare. A radioactive fallout study program has been established involving the systematic collection of air and precipitation samples from 24 locations, soil samples from 23 locations, fresh-milk samples from 16 locations, wheat samples from nine areas and human-bone specimens from various hospitals throughout Canada. A whole-body-counting facility and a special study of fallout in Northern areas have also been initiated. For any age group, the highest average strontium-90 concentration in human bone so far reported has been less than four picocuries per gram of calcium compared with the maximum permissible level of 67 derived from the International Committee on Radiation Protection (ICRP) recommendations. By the end of 1963 a general downward trend of levels of radioactivity detected in other parts of the program has been observed. Programs to assess the contribution to the radiation exposure of members of the population from medical x-rays, nuclear reactor operations and natural background-radiation sources have also been described. The annual genetically significant dose from diagnostic x-ray examinations in Canadian public hospitals has been estimated to be 25.8 mrem. Results from the reactor-environment monitoring programs have not suggested the presence of radioactivity beyond that contributed from fallout.