Urinary polycyclic aromatic hydrocarbons and monohydroxy metabolites as biomarkers of exposure in Coke-Oven workers

Objectives: To assess exposure to polycyclic aromatic hydrocarbons (PAHs) in coke oven workers using 13 unmetabolized PAHs (U-PAHs) and 12 monohydroxy metabolites (OHPAHs) in urine, and to make a comparative evaluation of the use of these biomarkers. Methods: Fifty five male Polish coke oven workers collected urine spot samples at the end of the workshift. U-PAHs (naphthalene, acenaphtylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo[a]anthracene, chrysene, benzo[k]fluoranthene, benzo[b]fluoranthene, benzo[a]pyrene) were determined by automatic solid phase micro-extraction followed by gas chromatography/mass spectrometry (GC/MS). OHPAHs (1- and 2-hydroxynaphthalene, 2- and 9-hydroxyfluorene, 4-, 9-, 3-, 1- and 2-hydroxyphenanthrene, 1-hydroxypyrene, 6-hydroxychrysene, 3-hydroxybenzo[a]pyrene) were determined, after liquid/liquid extraction and derivatization, by GC/MS. Results: U-PAHs, from naphthalene to chrysene, were found in 100% of the samples, while heavier U-PAHs were detected in 7 - 22% of the samples. OHPAHs up to 1-hydroxypyrene were found in 100% of the samples, while 6-hydroxychrysene and 3-hydroxybenzo[a]pyrene were always below the quantification limit. Median naphthalene, phenanthrene, pyrene, chrysene, and benzo[a]anthracene were 0.806, 0.721, 0.020, 0.032 and 0.035 µg/L, while hydroxynaphthalenes, hydroxyphenanthrenes, and 1-hydroxypyrene were 81.1, 18.9, and 15.4 µg/L. For each chemical, the ratio between U-PAH and the corresponding OHPAH ranged from 1:26 to 1:1000. Significant correlations between logged values of U-PAHs and OHPAHs, between U-PAHs, and between OHPAHs were found, with Pearson’s r ranging from 0.27 to 0.97. Conclusion: Analytical techniques currently available allow specific and simultaneous measurement of several urinary determinants of PAHs in humans. The results of these measurements support the use of U-PAHs as biomarkers of exposure and open the possibility of enlarging the spectrum of chemicals to be investigated, including carcinogenic chrysene and benzo[a]anthracene.