The study evaluated the relationship of occupational radiation exposure and mortality from several specific causes. The study showed that Hanford workers exhibited a strong healthy worker effect, having death rates substantially below those of the general U.S. population. Comparisons by level of exposure within the Hanford worker population provided no evidence of a positive correlation between exposure and mortality from all cancers combined or between exposure and mortality from leukemia.
The three analytic files in the HFC78A01 data set pertain to 44,101 Hanford workers initially employed at Hanford between 1944 and 1978. The first file (CEDR78_1) contains demographic, work history, and vital status data and indicators of internal depositions. Mortality data are provided for deaths occurring outside the state of Washington between 1944 and 1981, as well as for deaths occurring in Washington between 1944 and 1985. Internal deposition data include the radionuclide symbol and the year of first plutonium deposition. There is one record per individual. The second file (CEDR78_2) contains annual external whole- body doses that were compiled from external monitoring data for operations workers. These data include doses received while the worker was employed at other sites but, unlike another Hanford data set (HFI89A01), they do not include doses received while performing construction work at Hanford. There is one record for each year of exposure data for each of the 35,869 workers who were monitored. The third file (CEDR78_3) contains additional data related to onsite exposure and cause of death. There is one record for each worker.
The discussions in the published paper focus on monitored workers of both sexes. Dose response analyses (internal comparison) included 35,869 workers who were monitored for external radiation. Vital status was ascertained through December 31, 1981, the study end date. There were 4,846 deaths identified, and death certificates were obtained for 4,797 (99.0%) of these deaths. Comparisons with the U.S. general population included 42,291 white workers. There were 7,249 deaths identified, and death certificates were obtained for 7,155 (98.7%) of these deaths. Internal exposures were also examined.
Workers at the Hanford Site were involved in a variety of activities that resulted in their exposure to radiation, including reactor operations, chemical separation of reactor fuel to obtain plutonium, treatment and storage of hazardous waste, and biological and engineering research. Personal dosimeters (film or thermoluminescent) have been used since 1944. Also, bioassay programs to detect exposures to internally deposited radionuclides, primarily transuranics, were initiated in 1944. Dose estimates resulting from these monitoring programs appear in this analytic data set. Annual whole-body doses to penetrating external radiation are presented in units of millisieverts. Quality factors of 10 for fast neutrons, 3 for slow neutrons, and 1 for photons and electrons were used in the conversion of exposure to dose. Internal exposure data were collected and evaluated for all individuals who worked in locations where there was a potential for exposure to radioactive material (transuranics).