Diabetes and cancer in veterans of operation Ranch Hand after adjustment for calendar period, days of spraying, and time spent in Southeast Asia

BACKGROUND: The Air Force Health Study was launched in 1980 as part of a Federal effort to resolve the Agent Orange issue. OBJECTIVES: To study diabetes and cancer with additional adjustment for days of spraying, calendar period of service, and time spent in Southeast Asia (SEA). METHODS: This was a longitudinal study of veterans of Operation Ranch Hand, the unit responsible for spraying Agent Orange and other 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-contaminated herbicides in Vietnam from 1962 to 1971. RESULTS: Associations between TCDD and diabetes and between TCDD and cancer in Ranch Hand veterans are strengthened after adjustment for calendar period of service, days of spraying, and, for cancer, time spent in SEA. CONCLUSIONS: Calendar period of service, days of spraying, and time spent in SEA are important confounders in the Air Force Health Study.