The ZAFACW01 data set consists of three working files that were generated by the Epidemiology Section at the Los Alamos National Laboratory (LANL) for mortality studies of workers employed at Zia. Data were obtained in various formats and media from Zia, LANL departments, and other agencies. Demographic data were collected from three primary record sources provided by the Zia Company. Supplemental data were obtained from LANL's security badge book, personnel security questionnaires, LANL medical records, and LANL personnel records. Death information was abstracted from death certificates obtained from various states. Computerized data on exposure to external radiation and results of plutonium bioassays were obtained from the health physics department at LANL. Radiation protection and monitoring services are provided for Zia Company by LANL.
The three files in the ZAFACW01 data set are segegrated by type of data: demographic, external exposure, and plutonium bioassay results. Data pertaining to an individual that appear in one or more files may be linked by the individual pseudo-identifier number assigned to each worker.
The first working file (ZIAPFILE) contains demographic information, including birth and death dates, race, sex, work histories, coded cause of death, and state of death. The file includes 15,309 workers hired between 1946 and 1978, inclusive. The file includes data for 1,469 females, 11,215 males, and 2,625 workers with unknown sex. Race is determined for 74% of the workers. A roster of Zia workers was submitted to the Social Security Administration for vital status ascertainment. Information on vital status through December 31, 1984, was obtained in 1987. There are 4, 317 deaths identified in this working file.
The second working file (ZIAEFILE) contains external radiation exposure data consisting of annual whole- body doses (in centirem) where the whole-body dose was defined to be the sum of gamma, neutron, and tritium doses. Film dosimeters (badges) were used to measure exposures from 1944 through 1979, when thermoluminescent dosimeters (TLDs) replaced them. This file contains 44,452 records of exposure data from 1944 through 1985 for 5,911 monitored workers. These data include all measurements for individuals while working at Zia. Workers who were employed at Zia and also by LANL or another contractor may have measurements for both periods of employment. Therefore, all measurements in this file may not fall within a worker's period of employment at Zia.
The third working file (ZIABFILE) contains plutonium bioassay data for 1944 through October 1985. There are 35,434 records for 3,104 individuals. Measurements in 1944 are for nose swipes or urine samples. In March 1945, a formal bioassay program was established. Before 1968, all urine bioassay results were for plutonium-239 because that was the isotope used during that time. Beginning in 1968, the results are labelled as plutonium- 238 or plutonium-239. Until 1952, results were in units of cpm/24 hours; from 1952 through 1977, they were in dpm/24 hours; and from 1977 to 1985, they were in pCi/24 hours. Generally, they are annual measurements, but some individuals have multiple readings for one plutonium isotope within a year and some have separate readings for both isotopes within a year. All measurements are included in the file for each monitored worker. Some workers may have measurements that do not fall within the Zia period of employment.