| The Paducah Gaseous Diffusion Plant was located in western Kentucky. In response to concern about past and present radiation and chemical exposures, NIOSH funded a collaborative study by the Universities of Louisville, Kentucky, and Cincinnati to conduct an occupational cohort mortality study titled “Health effects of occupational exposures in PGDP workers.” The purpose of the study was to determine if PGDP workers had mortality patterns that differed from the general U.S. population and to investigate if mortality patterns were associated with job title or workplace exposures. |
| Demographic, work history, and vital status data were collected on 6,820 workers. Inclusion criteria required workers to have been employed at PGDP for at least 30 days from the start of plant operations in September 1952 through the end of study, December 2003. Work history, demographic, and exposure data were gathered from employee records at the Paducah Gaseous Diffusion Plant. For vital status, personal identifying information was submitted to the U.S. Social Security Administration or the National Death Index. For known deaths, death certificates were requested from the departments of health in the state the worker was believed to have resided. |
| This working data file set consists of one file, PGDPSW02_d1, generated for a worker mortality study of the Paducah Gaseous Diffusion Plant. |
| Information found in the working file includes demographic information, employment history including positions held and start and end dates for those positions, vital status, cause of death and underlying causes of death for deceased employees, relative exposure rankings for five metals (arsenic, beryllium, chromium, nickel, and uranium) and TCE, and actual or imputed yearly external and internal radiation exposure. The working file has 119,474 records and contains multiple records for each employee. Each record represents a time period in the worker’s employment history. Many workers changed job positions during their employment tenure, and therefore their exposures changed. In addition, exposures for the same job position changed over time. Each record represents a maximum of 1 year of employment history. |
| A total of 1,674 deaths were identified out of the 6,820 workers in the cohort. Sixtyone workers have incomplete history or outcome data, leaving complete data for 6,759 workers and 1,638 deaths. |
| Known exposures at the facility included metals (arsenic, beryllium, chromium, nickel, and uranium) and both internal and external radiation exposure. For metals, certain positions in the plant were known to have higher exposures compared with other positions. Because measurements for exposures were inconsistent throughout the plant’s history, a job exposure matrix was developed that ranked exposures based on the position within the plant and the time period worked. These ranks are relative exposure amounts and are based on few measurements. The job exposure matrix gave ranks on a scale of 0 (no exposure) to 5 (highest exposure). In the analysis of exposures, these ranks were condensed into low (0-1), medium (2-3), and high (4 5) exposure groups. |
| Measurements for radiation exposure were incomplete. For external radiation exposure, badge readings were used and average yearly exposures were determined for each grouped job title, and the average (based on number of days worked) was assigned to individuals with that job title that did not have measurements. For grouped job titles with no measurements in a year, the assigned value was the limit of detection (LOD)/sqrt(2)/365.25*number of days in time period. The LOD was 30 mrem prior to 1980 and 10 mrem from 1980 to the end of study. Four grouped job titles were considered to have no exposure and were assigned a value of 0. |
| The process for internal radiation exposure was similar. Measurements were in both disintegrations per minute and µg/L for specific radionuclides. More measurements were available in µg/L, so measurements in dpm were converted to µg/L, and a surrogate measure of internal radiation exposure in µg/L-years was employed. For employees with no measurements, values were imputed in the same manner as with the external radiation exposure. The LOD for internal radionuclide exposure was 5 µ/L. |
