Serum Dioxin and Hepatic Abnormalities in Veterans of Operation Ranch Hand

PURPOSE: We studied hepatic abnormalities and indices of hepatic function in relation to exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (dioxin) in veterans of Operation Ranch Hand, the Air Force unit responsible for the aerial spraying of herbicides in Vietnam from 1962 to 1971. METHODS: The prevalence of ever having liver disease through March 1993, and level of alanine aminotransferase, aspartate aminotransferase, γ-glutamyltransferase (GGT), lactic dehydrogenase (LDH), alkaline phosphatase, and total bilirubin were examined according to serum dioxin levels. RESULTS: We found an increased risk of “other liver disorders” among veterans with the highest dioxin levels [adjusted odds ratio (OR) = 1.6, 95% confidence interval (CI) 1.2 to 2.1], due primarily to increased transaminases or LDH (adjusted OR = 2.7, 95% CI 1.4 to 5.1) and to other nonspecific liver abnormalities (adjusted OR = 1.4, 95% CI 1.0 to 2.0). CONCLUSIONS: Whether the associations observed were causal is unclear from these data.