Mortality among a cohort of U.S. cadmium production workers--an update

A previous retrospective mortality study of 292 U.S. cadmium production workers employed for a minimum of 2 years showed increased mortality from respiratory and prostate cancer and from nonmalignant lung disease. To examine further the mortality experience of these workers, investigators from the National Institute for Occupational Safety and Health extended the study to include 602 white males with at least 6 months of production work in the same plant between 1940 and 1969. Vital status was determined through 1978, which included the addition of 5 years to the original follow-up. Cause-specific mortality rates for seven causes of death potentially related to cadmium exposure were compared between the overall cohort and U.S. white males and between subgroups. Mortality from respiratory cancer and from nonmalignant gastrointestinal disease was significantly greater among the cadmium workers than would have been expected from U.S. rates. All deaths from lung cancer occurred among workers employed for 2 or more years. A statistically significant dose-response relationship was observed between lung cancer mortality and cumulative exposure to cadmium. A 50% increase in lung cancer mortality, which was not statistically significant, was observed even among workers whose cumulative exposure to cadmium was between 41 and 200 micrograms/m3 over 40 years. Since the previous investigation, no new deaths from prostate cancer and no excess of deaths from nonmalignant respiratory disease have been observed.