Abstract
The population doses and risks of stochastic effects from occupational exposures in Japan in 1978 were estimated on the basis of a nationwide survey. The survey was conducted on annual collective dose equivalents by sex, age group and type of radiation work for about 82, 500 workers other than the workers in nuclear power stations. The data on the workers in nuclear power stations were obtained from the offitial publication of the Japan Nuclear Safety Commission. The total number of workers except for nuclear power stations was estimated to be about 170, 000 persons. Radiation works were subdivided as follows: medical works including dental; nondestructive inspectional ; non-atomic energy industrial; research and educational; atomic energy industrial and nuclear power industrial.
The annual collective dose equivalents were estimated to be about 6, 000 man rem for medical workers, 450 man rem for non-destructive inspectional, 450 man rem for non-atomic energy industrial and 13, 300 man rem for nuclear power industrial, respectively. The population doses from occuaptional exposures in Japan were calculated to be about 0.14 mrad person-1 year-1 for the genetically significant dose, 0.15 mrad person-1 year-1 for per Caput mean bone marrow dose, 0.14 mrad person-1 year-1 for the leukemia significant dose and 0.07 mrad person-1 year-1 for the malignancy significant dose, respectively. The risks of stochastic effects to individual and the Japanese population from occupational exposures were estimated using the data on the annual collective dose equivalent to individual and on the population doses, respectively. The total risk of population was estimated to be about 4 persons year-1. The analyses of occupational exposures such as the dose equivalent per unit electrical power generated by nuclear energy or per radiological practice to patients were carried out.
