Abstract:
In vitro assessments of 14C-benzo[a]pyrene (BaP) absorption through human epidermis were conducted with the sub-63-µm fraction of four test soils, containing different amounts of organic and black carbon. Soils were artificially weathered and applied to epidermis at BaP concentrations of 3 and 10 mg/kg for 8 or 24 h. Experiments were also conducted at 24 h with unweathered soils and with BaP deposited onto skin from acetone at a comparable chemical load. For the weathered soils, absorption was independent of the amount of organic or black carbon, the mass in the receptor fluid was proportional to exposure duration but independent of concentration, and the mass recovered in the skin after washing was proportional to concentration and independent of exposure time. Results from the weathered and unweathered soils were similar except for the mass recovered in the washed skin, which was lower for only the higher concentration by less than 50%. The findings are consistent with concentrations that exceeded the BaP sorption capacity of all soils tested, and with BaP mass in the wash skin dominated by particles that were not removed by washing. Flux into and through skin from soils were lower by an order of magnitude from acetone-deposited BaP.
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