Hexachlorobenzene distribution in tissues of swine

Purified hexachlorobenzene (HCB) was administered to third-litter sows at dietary concentrations of 0, 1, or 20 ppm throughout gestation and nursing. Swine receiving 1 ppm were not adversely affected and residue concentrations in tissues other than fat and bone marrow remained at or below the dietary concentration. Residues of HCB in the dissectable fat of these pigs accumulated to concentrations five- to seven-fold higher than the dietary concentration. Piglets accumulated fat residues, through both placental transfer and nursing, that were higher than those of the sows. A similar proportional accumulation of HCB in fat occurred in sows receiving 20 ppm in the diet. Other toxic signs included neutrophilia, gastric irritation, fatty replacement of Brunner's gland, and pancreatic periductal fibrosis. Hepatotoxicity was not apparent, perhaps because of age-related changes in both control and treatment groups.