Abstract
This paper deals with an evaluation of radiation dose received by X-ray workers in the past days of Japan. For this evaluation, radiation dose received by X-ray workers is considered to be influenced by the following six factors: that is, attention to X-ray protection, sensitivity of X-ray films, sensitivity of intensifying screens, shield of control board, shield of X-ray tube, and quantity of X-ray work. Collection of data from actual history of radiological work in the hospitals and from literature was made and comparable considerations were given on these data between in the past and at present. The most suitable evaluation of radiation dose per year received by individual X-ray worker is considered to be 0.31 R at present, 1.55 R before 1957, 9.3 R before 1953, 90 R before 1945, 240 R before 1940, 350 R before 1935, 520 R before 1930, 680 R before 1926. and 900 R before 1921.
