Urinary 1-naphthol and 1-pyrenol as indicators of exposure to coal tar products

Chemical exposure of assemblers handling creosote-impregnated wood and of a single worker chiselling coal tar pitch layer was assessed by measuring airborne naphthalene and various polycyclic aromatic hydrocarbons (PAHs), and by measurement of urinary excretion of 1-naphthol and 1-pyrenol. The sum concentration of PAHs and of 4-6 aromatic ring-containing PAHs were high, 440 micrograms/m3 and 290 micrograms/m3, respectively, when chiselling. In the assembler's workplace, the PAH concentrations were about 1/50 of this value. Regarding airborne naphthalene concentrations the situation was reversed (assemblers, 1000 micrograms/m3; chiseller, 160 micrograms/m3). Correspondingly, the assemblers' urinary 1-napthol concentrations were 15-20 times higher than those of the chiseller. The urinary 1-pyrenol concentration of the chiseller was 2-4 times higher than among the assemblers. As the estimated pyrene inhalation doses among the assemblers could account for only about 2%-25% of the 24-h pyrenol excretion in urine, the skin was presumably the main route of uptake. For an assessment of the exposure to PAHs, air measurements, monitoring of metabolites in urine and preferably also data on the composition of the skin-contaminating product are needed.