Urinary profiles to assess polycyclic aromatic hydrocarbons exposure in coke-oven workers

Aim of the study was the assessment of exposure of coke-oven workers to polycyclic aromatic hydrocarbons (PAHs) by determination of urinary profiles of hydroxylated and unmetabolized PAHs. Fifty-five Polish coke-oven workers were investigated by measurement of 12 hydroxylated metabolites of PAHs (OHPAHs) (1-, 2-hydroxynaphthalene; 2-, 9-hydroxyfluorene; 1-, 2-, 3-, 4-, 9-hydroxyphenanthrene; 1-hydroxyypyrene, 6-hydroxychrysene and 3-hydroxybenzo[a]pyrene) and 13 unmetabolized PAHs (U-PAHs) (from naphthalene to benzo[a]pyrene), in spot urine samples collected at the end of the workshift. U-PAHs with four or less rings were detected in all samples. In particular, median levels for urinary naphthalene, phenanthrene, pyrene, chrysene and benz[a]anthracene were 0.806, 0.721, 0.020, 0.032 and 0.035 microg/L. OHPAHs up to 1-hydroxypyrene were found in all samples, while high molecular-weight OHPAHs were always below quantification limit. Median level of 1-hydroxyypyrene was 15.4 microg/L. In all subjects significant correlations between OHPAHs and U-PAHs were observed (0.27 < r < 0.70, p < 0.01). Our results suggest that both hydroxylated metabolites and unmetabolized PAHs in urine are useful biomarkers of exposure to PAHs. Moreover, the simultaneous determination of several biomarkers permits to obtain specific excretion profiles that might help in exposure characterization and in better defining the excretion patterns.