A mortality study of 76,160 men who served on US nuclear submarines is
reported. Indirect standardization was used to compare mortality rate
s to those of the US male population. Multiplicative models were devel
oped to explore patterns of mortality within the cohort. Mortality rat
es for leukemia, acute myocardial infarction, and for motor vehicle ac
cidents were equivalent to those of US males; rates for other causes w
ere lower, generally consistent with the ''healthy worker effect.'' Mo
tor vehicle accident mortality dropped during the study period, perhap
s reflecting efforts to control the problem. Suicide rates were depres
sed during the period of active duty. There was a suggestion that canc
er mortality was associated with submarine type; however, the age dist
ribution casts doubt that the excess was occupationally induced.