This study continues to examine the relationship between occupational radiation exposure among Hanford workers and mortality from specific causes. The files used for this paper have been updated and refined since the 1989 publication. The study showed that both male and female workers continue to exhibit a strong healthy worker effect, with death rates from most causes substantially below those of the general U.S. population. Comparisons by level of radiation exposure within the Hanford worker population provided little evidence of a positive correlation between cumulative radiation exposure and mortality from leukemia or from all other cancers combined.
The three analytic files in the HFI89A01 data set pertain to 44,156 Hanford operations workers initially employed at Hanford between 1944 and 1978. The first file (IARC89_1), with one record per individual, contains demographic, work history, vital status, and internal deposition data. Mortality data are provided for deaths occurring outside Washington State between 1944 and 1986, and deaths occurring in Washington between 1944 and 1989, inclusive. Internal deposition data include the radionuclide symbol and the year of first plutonium deposition. The second file (IARC89_2), contains external exposure data for the years 1944 through 1989. The dosimetry data include doses received while performing construction work at Hanford as well as occupational doses received offsite at other facilities. There is one record for each year of exposure data for each of the 37,012 monitored workers. The third file (IARC89_3) contains additional data related to internal exposures, offsite exposures, and cause of death. There is one record for each worker.
Comparisons with the U.S. general population included a cohort of 42,070 white workers. There were 9,452 deaths identified, and death certificates were obtained for 9,285 (98.2%) of these deaths. Dose response analyses included 32,643 workers (24,672 males and 7,971 females) who were monitored for external radiation and employed for at least 6 months between 1944 and 1985. Vital status was ascertained through 1986, the study end date. There were 6,286 deaths identified, and death certificates were obtained for 6,200 (98.6%) of these deaths. Both types of analyses included deaths through December 31, 1986.
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. Bioassay programs to detect exposures to internally deposited radionuclides, primarily transuranics, also were initiated in 1944. Dose estimates resulting from these monitoring programs appear in this 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 intake of radioactive material (transuranics).