Percutaneous absorption and skin decontamination of PCBS: In vitro studies with human skin and in vivo studies in the rhesus monkey

Abstract

Knowledge of the entry of polychlorinated biphenyls through the skin into the body and subsequent disposition aids estimation of potential for human health hazard. [¹⁴C]Aroclor 1242 and [¹⁴C]Aroclor 1254 were separately administered intravenously and topically to rhesus monkeys. Following iv administration, 30‐d excretion was 39.4 ± 5.9% urine and 16.1 ± 0.8% feces (total 55.5 ± 5.1%) for Aroclor 1242, and 7.0 ± 2.2% urine and 19.7 ± 5.8% feces (total 26.7 ± 7.5%) for Aroclor 1254. Mineral oil and trichlorobenzene are common PCB cosolvents in transformers. Skin absorption of Aroclor 1242 was 20.4 ± 8.5% formulated in mineral oil and 18.0 ± 3.8% in trichlorobenzene (p > .05). Absorption of Aroclor 1254 was 20.8 ± 8.3% in mineral oil and 14.6 ± 3.6% in trichlorobenzene (p > .05). PCBs are thus absorbed through skin, and excretion from the body is slow. Vehicle (trichlorobenzene or mineral oil) did not affect percutaneous absorption.

In vitro skin absorption in human cadaver skin did not correlate with in vivo findings. This was due to lack of PCB partition from skin into the water receptor fluid, even with addition of 6% Oleth 20 (Volpo 20) solubilizer.

Skin decontamination of PCBs showed soap and water to be as effective as or better than the solvent ethanol, mineral oil, and trichlorobenzene in removing PCBs from skin. There is a dynamic time lapse for PCBs between initial skin contact and skin absorption (irreversible removal). Thus initially most PCBs could be removed from skin, but this ability decreased with time to the point where at 24 h only about 25% of the initial PCB skin dose could be recovered with skin washing.