DERMAL ABSORPTION OF POLYCYCLIC AROMATIC-HYDROCARBONS IN THE BLOOD-PERFUSED PIG EAR

Urinary 1-OH-pyrene, a metabolite of pyrene, is,a sensitive biological marker for dermal absorption of pyrene in man. In order to determine whether this metabolite is a reliable biomarker of cutaneous absorptio n of other polycyclic aromatic hydrocarbons (PAHs), the blood-perfused pig ear model was used to compare the dermal absorption flux of pyren e with nine other PAHs after coal tar application. Cumulative absorpti on of PAHs into the perfusion blood, 200 min after application of an o verdose of coal tar, ranged between 830 pmol cm(-2) for phenanthrene t o less than 4 pmol cm(-2) for benzo[b]fluoranthene, benzo[k]fluoranthe ne, benzo[a]pyrene, dibenzo[ah]anthracene and indeno[123-cd]pyrene. Th e results of this study show that when pyrene is used as a marker comp ound for PAH absorption through pig skin, the cumulative absorption of PAHs with a lower molecular weight will be underestimated: fluorene, tenfold; phenanthrene, 12-fold; anthracene and fluoranthene, ca. twofo ld. The percutaneous absorption of PAHs with a higher molecular weight than pyrene will be overestimated: e.g. benzo[a]pyrene, sevenfold; in deno [123-cd]pyrene, ca. 100-fold. It is likely that this conclusion i s also valid for dermal PAH absorption in man.