Health status of Air Force veterans occupationally exposed to herbicides in Vietnam. II. Mortality.

The Air Force Health Study is a 20-year comprehensive assessment of the current health of Air Force veterans of Operation Ranch Hand, the unit responsible for aerial spraying of herbicides in Vietnam. This report compares the noncombat mortality of 1261 Ranch Hand veterans to that of a comparison population of 19,101 other Air Force veterans primarily involved in cargo missions in Southeast Asia but who were not exposed to herbicides. The indirectly standardized all-cause death rate among Ranch Hands is 2.5 deaths per 1000 person-years, the same as that among comparison subjects. After adjustment for age, rank, and occupation, the all-cause standardized mortality ratio was 1.0. In adjusted cause-specific analyses, we found no significant group differences regarding accidental, malignant neoplasm, and circulatory deaths. These data are not supportive of a hypothesis of increased mortality among Ranch Hands.