1997 年 32 巻 2 号 p. 173-184
The health effects of low doses and low dose rates exposure to human bodies have not been clarified yet. Under this situation, the Radiation Effects Association entrusted by the Science and Technology Agency of the Japanese Government began a survey entitled “The Epidemiological Study on Nuclear Industry Workers.”
The study population consisted of 114, 900 workers in the nuclear industry. Their vital status and identification of cause of death were confirmed by residence registration records and by magnetic tapes of National Vital Statistics, respectively. Their dose information was obtained from the Radiation Dose Registration Center for Workers. The total population dose of the study population was 1, 598.5 person-Sv, and the mean cumulative dose per individual was 13.9mSv. The study period was between 1986 and 1992, average follow-up period being 4.6 years. There were 1, 758 deaths including 661 of all malignant neoplasms among the population.
The SMR was used to compare mortality among members of the study population and that of Japanese males in general after adjustment for age distribution. Furthermore, members of the population were grouped by cumulative dose groups, and the O/E was calculated to test whether there is a trend for the death rate to increase with dose.
The present study demonstrated no evidence of any effect of low level radiation upon health, particularly upon the cancer mortality.
