Distribution, dilution and elimination of polychlorinated biphenyl analogs in growing swine.

Growing swine were given 15 mg/kg po of purified polychlorinated biphenyl analogs and a commercial mixture. Backfat biopsies for 16-18 weeks exhibited two-compartment elimination kinetics when based on concentration. Total body fat was estimated from potassium-40 abundance, and the calculated total fat load indicated that most of the decline in residue concentrations was due to dilution by growth and expansion of the fat compartment. Redistribution in the fat was apparent for various analogs at different times, and tissue distribution varied significantly among analogs.