The single analytic file (MOSTEXP) in this data set consists of one record per person in the study cohort and contains demographic, work history, and vital status data as well as information concerning exposures to chemicals and uranium. Examples of these are exposures to uranium hexafluoride, nitric acid, and hydrofluoric acid.
The cohort was selected from a roster of all persons ( 1,551) employed at the Linde Plant, which was in operation from 1943 to 1949. All females, non-white males, males of unknown race, and people employed less than 30 days were excluded, leaving 995 white males in the study cohort. Vital status was ascertained for 94. 3% of the cohort through December 31, 1979, the study end date. There were 429 deaths identified, and death certificates were obtained for 406 (94.6%) of these deaths.
At the Linde Plant, Congo pitchblende and uranium from domestic mines were converted to uranium tetrafluoride. This process yielded intermediate products, including uranium oxide, uranium trioxide, and uranium dioxide. Compared to uranium tetrafluoride, these products are relatively insoluble. Workers were also potentially exposed to low levels of external radiation and to a wide variety of chemicals. The more hazardous chemicals included chlorine, hydrofluoric acid, lead sulfate, nickel, nitric acid and nitrogen oxides, silicon dioxide, sulfuric acid, uranium dust, and uranium hexafluoride. Generally, four types of measurements contained information useful in assessing radiation hazards. They were (1) air monitoring results for radon-222 and airborne uranium, (2) measurements of surface contamination, (3) urinalysis results, and (4) personnel film badge results. The first three types of measurements were used to assess the potential for internal radiation exposure for each job that existed at the plant. Three separate analyses were carried out using each type of data, and the results were combined to assign a given job to one of three exposure groups. These data also were used to estimate individual lung doses. The limited film badge data were used to evaluate the potential for exposure to external radiation. Each job at the plant was assigned to one of two categories, namely, jobs with mean weekly film badge results below the minimum detectable level and jobs with mean weekly film badge results above the minimum detectable level.