Polychlorinated Biphenyls

Abstract

Rats were fed 100 ppm of Aroclor 1242 (6.6 to 3.89 mg/kg/day) or 100 ppm Aroclor 1016 (6.9 to 3.5 mg/kg/day). Plasma, kidneys, urine, brain, liver, and adipose tissue were analyzed for polychlorinated biphenyl (PCB) residues at 0.5, one, two, four, six, eight, and ten months of exposure. In additional groups fed the experimental diet for six months, PCB tissue levels were determined two, four, five, and six months after the exposure to PCBs was discontinued. PCBs were highest in adipose tissue where a steady state was approached in two and reached in 4 months. Little PCB-derived material was excreted in urine. After discontinuing PCB exposure, Aroclor 1016 was eliminated more rapidly from the organs than Aroclor 1242. Measurable residue levels were still present after five (Aroclor 1016) and six (Aroclor 1242) months of recovery. Microscopic examination of the liver showed enlarged liver cells with vacuolated cytoplasm and inclusions.