Reliable quantification of 1,2-dihydroxynaphthalene in urine using a conjugated reference compound for calibration.
Urinalysis of multiple polycyclic aromatic hydrocarbons (PAH) biomarkers has been applied to assess the exposure of soil remediation workers on a former creosote wood impregnation site polluted with creosote oil. The uptake of PAHs was measured in preshift, end-of-shift, evening, and next preshift specimens (n=33) of nine volunteers with diverse tasks, using sensitive HPLC-FD methods. The ranges of biomarker concentrations in urine (nmol/l) were: 1-naphthol (14-159), 2-naphthol (9-166), 1- plus 2-naphthol (35-269), 1-hydroxyphenanthrene (OHPhe) (6-56), 2- plus 3-OHPhe (6-70), 4-OHPhe (1-6), 9-OHPhe (1-7), the sum of phenanthrols (15-135), and 1-hydroxypyrene, OHP (2.2-67). Eight of nine workers had OHP levels higher than the Finnish biological limit value for non-occupationally exposed persons (3nmol/l). A linear correlation was observed between 1- and 2-naphthol (r=0.90). The biomarker OHP correlated well in urine both with the major (1-OHPhe, r=0.96; 2- plus 3-OHPhe, r=0.84) and the minor phenanthrene metabolites (4-OHPhe, r=0.77; 9-OHPhe, r=0.68), and with the sum of all phenanthrols (r=0.94), but not so well with the sum of naphthols (r=0.66, p<0.001). The smokers had 2.9-, 2.2-, and 4.8-fold higher average concentrations of naphthols, phenanthrols, and OHP, respectively, than the non-smokers. The PAH biomarker data (concentrations and diurnal excretion profiles) showed significant work-related exposure in both non-smoking and smoking subjects. The average exposure levels were clearly higher than those we have measured for instance in asphalt paving workers. The workers' exposure should be assessed by biological monitoring, because at this type of outdoor work the dermal and pulmonary uptake of PAHs are both likely. Adequate measures for preventing, particularly, dermal absorption are of crucial importance for reducing the workers' risk of exposure to carcinogens on soil remediation sites.