Epidemiological assessment of the cancer risk among the staff in radiotherapy departments in Denmark

Preliminary results are given here of a study of the cancer incidence among nurses, doctors and others exposed to ionizing radiation during their work in two Danish hospitals over the period 1954-1984. The number of persons is small (4281) and only few (3.6%) received cumulated doses above 0.1 Sv which is the order of the life-time dose from natural radiation sources. Therefore no relation between exposure and cancer incidence could be evaluated. The number of incident cancers of all types is not different from the number expected for the whole group, i.e. the relative risk, RR, is approx. 1.00, but the value was significantly increasing and exceeding 1.00 as the period of observation was increased. One reason for carrying out this investigation was the question of a possible higher incidence for certain types of cancers in this group of workers irradiated in the past. The possibility exists for cancer of breast and prostate, although the incidences are not significantly elevated. (author)