Mortality among men employed between 1943 and 1947 at a uranium-processing plant.

Mortality is described in a cohort of 18,869 white males who were employed between 1943 and 1947 at a uranium conversion and enrichment plant in Oak Ridge, Tenn. Workers in certain departments (especially chemical workers) were exposed to high average air levels of uranium dust. Based on deaths reported in 1974 by the Social Security Administration (SSA) and using mortality rates for U.S. white males, standardized mortality ratios (SMRs) for various causes in the entire cohort were generally less than 1.00. After correction for unascertained deaths and missing death certificates, the SMR for lung cancer was 1.22 (95% confidence limits, 1.10 and 1.36). SMRs for various causes, including lung cancer, did not tend to be higher in 8,345 workers employed in areas where uranium dust was present or in 4,008 of these 8,345 workers employed for one year or longer at the plant. Other causes of particular interest (i.e., bone cancer, leukemia, diseases of respiratory and genitourinary systems) did not exhibit high SMRs. The suggestive finding of the authors was an increased number of lung cancer deaths in a group of chemical workers hired at greater than or equal to 45 years of age. Continued follow-up of the cohort is necessary for further evaluation of the long-term health effects of exposure to uranium.