Immunochemical test to monitor human exposure to polycyclic aromatic hydrocarbons: urine as sample source

Measurement of urinary metabolites constitutes a non-invasive method to assess exposures resulting from all routes. An immunochemical assay (enzyme-linked immunosorbent assay) was applied for the detection of metabolites excreted in urine as the result of exposure to polycyclic aromatic hydrocarbons (PAHs). Ten male subjects potentially exposed to PAHs were employed in road bituminization. Same number of referents came from university staff. The metabolites were analyzed in an indirect competitive ELISA, using a polyclonal antiserum that has been raised against pyrenebutyric acid coupled to thyroglobulin and l-hydroxypyrene as a calibrator. Antiserum specificity was tested with several PAH metabolites. Binding was highest for l-hydroxypyrene (100%), was acceptable for 1-hydroxypyreneglucuronide (22%) and the phenanthrols (6-32%), but was low (<1%) for 1-hydroxypyrenesulfate, 1-naphthol, and 3-hydroxybenzo(a)pyrene. No binding was observed with 9,10-dihydroxy-9,10-dihydrophenanthrene. Results given as l-hydroxypyrene equivalents were compared to the l-hydroxypyrene concentration as determined by off-line solid phase extraction/HPLC analysis and the sum of 1-, 2-, 3-, 4-, 9-hydroxyphenanthrenes and l-hydroxypyrene from coupled-column HPLC analysis. All metabolite concentrations were corrected for creatinine. PAH metabolites were detected in all of the urine samples. Results obtained with the ELISA in most samples were higher than corresponding l-hydroxypyrene concentrations and lower than the sum of phenanthrols and I-hydroxypyrene as measured by HPLC. With both HPLC and the ELISA. no significant difference in PAH metabolite excretion of exposed subjects and referents was found, whereas urinary PAH excretion was significantly higher in smokers compared to non-smokers. It is concluded that the ELISA has proved to be a useful tool for biomonitoring studies that allows an estimation of PAH urinary excretion after a simple sample dilution and without any time-consuming preliminary enzymatic hydrolysis or derivatization. (C) 1999 Elsevier Science B.V. All rights reserved.