Vietnam veterans who were heavily exposed to Agent Orange exceeded matched control subjects in both blood and adipose tissue levels of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) but not in the levels of the 12 other 2,3,7,8-substituted dioxins and dibenzofurans that were detected. Since only TCDD among these compounds was present in Agent Orange but all are present in the population of the industrialized world, it is likely that the elevated TCDD levels arose from wartime exposure. The high correlation (r= +.89) of blood with adipose tissue level suggests that there may be a mobile equilibrium between them and that blood measurement could replace adipose tissue measurement of TCDD levels, making the collection of human data less invasive.
(JAMA 1988;259:1661-1667)