Second analysis of mortality of nuclear industry workers in Japan, 1986-1997

This article is a commentary concerning the second report of the study in the title committed by the Science and Technology Agency (the present Ministry of Education, Culture, Sports, Science and Technology) to Radiation Effects Association. The study is an epidemiological one as for the relationships between long-term low dose radiation and its health effects in workers of nuclear industry like nuclear power plant and uses the cohort methodology for the factor (exposure dose) and diseases (mortality). In about 244,000 personnel, mortality was calculated from obtainable 179,000 resident cards of object males. For those died during the study period, cause of death was checked with the card for the movement of population (Ministry of Health, Labor and Welfare). The exposure dose was checked with the dose records of radiation workers stored in the registration center. Analysis results of standardized mortality ratio (comparison of mortality of the objects and non-object Japanese males) and of correlation of integrated dose and mortality gave no clear evidence that the low dose radiation exposure affects the mortality due to cancer. (K.H.)