Enhanced faecal excretion of 2,3,4,7,8-pentachlorodibenzofuran in rats by a long-term treatment with activated charcoal beads.

1. The effect of activated charcoal beads on the faecal excretion of 2,3,4,7,8-pentachlorodibenzofuran (PenCDF), a causal agent of yusho, which accumulates in the body, was studied for 12 weeks in rats. 2. Diets supplemented with 1% and 5% activated charcoal beads stimulated faecal excretion of PenCDF about 2- and 4-fold, respectively. The concentration of PenCDF in liver, the major storage site, was decreased significantly and dose-dependently by the treatment. 3. The charcoal bead treatment decreased the extent of fatty liver, thymic atrophy, and induction of hepatic benzo[a]pyrene hydroxylase.