Dermal exposure to polycyclic aromatic hydrocarbons in asphalt workers

Objectives To assess dermal exposure to 16 polycyclic aromatic hydrocarbons (PAHs) in asphalt workers by applying polypropylene pads to six body sites (neck, shoulder, upper arm, wrist, groin, ankle), to identify the compounds and exposure sites most representative, and to integrate dermal exposure results with environmental and biological data. Methods Twenty-four asphalt workers were recruited. Dermal exposure was assessed during a single work shift. Sixteen PAHs (from naphthalene to indeno[1,2,3-cd]pyrene) were quantified via gas chromatography-mass spectrometry. Airborne exposure, urinary PAHs and monohydroxy metabolites were also investigated. Results Phenanthrene (PHE), present in all samples, was the most abundant compound (median 0.805-1.825 ng/cm(2)). Benzo[a] pyrene (BaP) was present in 75% of the samples (0.046-0.101 ng/cm(2)). Wrist had the highest contamination, with median PHE, pyrene (PYR), and BaP concentrations of 1.825, 0.527, and 0.063 ng/cm(2). PHE and PYR on wrist correlated with almost all 3- to 4-ring PAHs (0.405 <= r <= 0.856), but not with BaP; BaP correlated with almost all 4- to 6-ring PAHs (0.584 <= r <= 0.633). Significant correlations were observed between PHE level, airborne exposure, and the corresponding urinary PHE and monohydroxy metabolites. For PYR, significant correlations existed only between urinary PYR and monohydroxy metabolites. Multiple linear regression analysis revealed that 42% of the end-of-shift monohydroxy metabolites were the result of airborne exposure, dermal exposure, and baseline levels of biomarkers. Conclusions Dermal exposure to PAHs was in the low ng/cm(2) range. PHE or PYR and BaP were the most representative compounds and the wrist was the best location to perform dermal exposure assessments. Both dermal and airborne exposure contributed to the total body burden of PAHs, though the relative contribution was analyte-dependent.