Abstract
The biological half‐lives of five dibenzo‐p‐dioxins and two dibenzofurans were determined in rainbow trout following a single oral exposure. Estimated half‐lives ranged from 2 d for 2,7‐dichlorodibenzo‐p‐dioxin to 43 d for 1,2,3,4‐tetrachlorodibenzo‐p‐dioxin among the dioxins, and from 12 d for octachlorodibenzofuran to 24 d for 3,6‐dichlorodibenzofuran. No consistent relationship was shown between half‐life and the degree of chlorination. Absorption efficiencies varied from 2 to greater than 30%, although most values ranged from 5 to 16%.