Polycyclic Aromatic Hydrocarbons in Newspaper Inks: Migration, Metabolism, and Genotoxicity in Human Skin

Abstract

Polycyclic aromatic hydrocarbons (PAHs), such as benzo[a]pyrene (BP), are detectable in certain consumer products, including newspapers. We investigated the release of PAHs from newspapers and the fate and effects of BP in human skin models. The migration and penetration of BP into the dermal layers was shown using pig skin. Upon treatment the stratum corneum was gradually removed by tape strips and all samples were subsequently analyzed. BP could be detected in newspapers at levels of up to 52 μg/kg via LC-APPI-MS/MS. We also could show that PAHs such as BP are able to penetrate from the surface into deeper layers of the skin. In addition, the migration of different PAHs including BP from newspapers into a sheet of polyethylene as skin simulant was demonstrated. We further report on the biotransformation of BP in various three-dimensional human skin models and cultures of human keratinocytes or fibroblasts (5). The metabolic profiles observed by means of LC-APCI-MS/MS contained seven major BP follow-up products (i.e., 3- and 7-phenol, 1,6- and 7,8-dione, 7,8-, and 9,10-diol, 7,8,9,10-tetraol) and thus resembled the profiles detected in human skin ex vivo. In the frame of these studies, we also confirmed the genotoxicity of BP and its metabolites in the skin models via comet assay.