A Retrospective Cohort Study of Mortality and Cancer Incidence Among Chemists

This retrospective cohort study examines mortality and cancer incidence among 3,686 men and 75 women who were employed as chemists in 1959. During the period 1964 to 1977, the male chemists experienced lower overall mortality than other salaried employees of the chemical company (198 deaths observed, 241.0 expected, SMR = 82). Large deficits are seen in lung cancer and arteriosclerotic heart disease death. The chemist appear to be at slightly higher risk for death from malignancies of the colon (12 observed, 6.7 expected, SMR = 178) and from cerebrovascular disease (15 observed, 10.8 expected, SMR = 138). The low overall mortality resulted in a larger than expected proportion of deaths due to cancer. Fewer than expected cases were diagnosed of cancer of all sited combined (61 observed, 86.5 expected, SIR = 71) and of the lung (8 observed, 20.0 expected, SIR = 40). The incidence rates of melanoma and of cancer of the prostate are slightly higher than expected, relative to the Third National Cancer Survey and the experience of nonchemists, respectively. Among female chemists, deaths due to all causes and suicide occurred more frequently than expected. Possible explanations for the lack of anticipated excess risks and for the observed deficits are presented.