PCB profiles in mouse skin biopsies and fat from an environmental mixture

Fat, ear skin and trunk skin were collected from mice exposed to PCB-contaminated soil for PCB specific congener analysis. The soil had been retrieved from a Superfund site prior to remediation. Mice were exposed to either contaminated soil or control soil for 4 weeks. Skin samples were collected immediately after the 4-week exposure and again after 4-week recovery. Out of 141 PCB congeners measured, only 91 peaks representing 103 congeners were above quantification limits. Relative liver weights in PCB-exposed mice doubled indicating significant enzyme induction. Consistent with this observation, total PCB residues declined about 80% during the 4-week recovery. The PCB residue profiles in the ear skin (208 mg/kg total) and trunk skin (129 mg/kg) after 4-week exposure were identical and similar to those in body fat (370 mg/kg) and in the contaminated soil. The results confirmed that both skin tissues are important reservoirs and can serve as useful biopsy media.