PERCUTANEOUS-ABSORPTION OF PCBS FROM SOIL - IN-VIVO RHESUS-MONKEY, IN-VITRO HUMAN SKIN, AND BINDING TO POWDERED HUMAN STRATUM-CORNEUM

Polychlorinated biphenyls (PCBs) are ubiquitous and persistent environ mental pollutants. The major resident site for these PCBs is the soil, and human skin is frequently in contact with soil. Our objective was to determine the percutaneous absorption of the PCBs Aroclor 1242 and Aroclor 1254 from soil. PCB-contaminated soil was prepared at levels o f 44 ppm Aroclor 1242 and 23 ppm Aroclor 1254. PCB concentrations on s kin were 1.75 mug/cm2 for Aroclor 1242 and 0.91 mug/cm2 for Aroclor 12 54. In vivo percutaneous absorption in the rhesus monkey was determine d by urinary and fecal [C-14]-PCB excretion for a 5-wk period followin g topical dosing. Absorption of Aroclor 1242 was determined in vitro w ith human skin for comparative purposes. In vivo in the rhesus monkey the percutaneous absorption of Aroclor 1242 was 13.8 +/- 2.7 (SD)% of the dose and the absorption of Aroclor 1254 was 14.1 +/- 1.0%. These a bsorption amounts are similar to the absorption of Aroclor 1242 and 12 54 from other vehicles (mineral oil, trichlorobenzene, acetone). With in vitro percutaneous absorption through human skin, most of the Arocl or 1242 and Aroclor 1254 resided in the skin and the amounts were depe ndent upon dosing vehicle (water > mineral,oil > soil). Both PCBs read ily partitioned from water into soil and human powdered stratum corneu m. By difference the partitioning favored both PCBs going from soil in to stratum corneum. These data emphasize the role of soil in percutane ous absorption and provide information for appropriate risk assessment .