The Cancer Hazards of Industrial and Accidental Exposure to Radioactive Isotopes

The location and relative numbers of rediosensitive cells and of cells not considered to be rediosensitive in bone and in bone marrow

“…One case might have been expected as the natural incidence. One further case recorded on the death certificate could not be confirmed on investigation (Evans, 1966;Hasterlik, Finkel and Miller, 1964). The possible effect of gamma irradiation in producing leukaemia in radium workers exposed to external radiation must not be forgotten.…”

“…The time of onset for sarcomas was 7-43 years (median 23 years) after first exposure; for carcinomas it was 19-51 years (median 39 years) after first exposure. The data of Hasterlik, Finkel and Miller (1964) shown in Table 1 might suggest a dependence of incidence on body burden. However, within the body burden limits of Evans' data, good agreement exists between the two.…”

“…The available biological data suggest that induction of malignant change should be regarded as the limiting factor in considering maximum permissible levels for bone since other crippling degenerative changes have not been seen when the dose is less than the carcinogenic dose. This statement is based on two extensive studies of patients who have a known body burden of radium and also on experimental results on animals (Evans, t966, 1967;Finkel, Miller and Hasterlik, 1964;Hasterlik, Finkel and Miller, 1964). In Table 1 is shown an analysis of the Chicago patients where a correlation between clinical and radiographic findings with current body burdens of 226Ra is made.…”

“…In human skulls carcinomas arise in the mastoid air cells and paranasal sinuses (Dudley, 1960;Hasterlik, Finkel and Miller, 1964;Hasterlik and Finkel, 1965;Evans, 1966). Anatomically these are among the few areas in the human skeleton where epithelium is directly adjacent to bone (Beal, Lindsay and Ward, 1965).…”

“…Squamous epithelium is not normally present in the mastoid air cells but may occur under certain circumstances (Friedmann, 1956 a and b;1966, personal communication). The total thickness of the epithelium and connective tissue in man in the paranasal sinuses and the mastoid air cells is reported to be 50-100/zm (Hasterlik, Finkel and Miller, 1964), and there-fore the proliferating cells may lie within the range of radium alpha particles emerging from the underlying bone.…”