Urinary biomarkers of exposure to jet fuel and polycyclic aromatic hydrocarbons

Polycyclic aromatic hydrocarbons (PAHs) and jet propulsion fuel-8 (JP-8) are complex mixtures composed of several hundreds of different chemicals that pose health risks to thousands of workers worldwide. Naphthalene is an important constituent of both mixtures, and thus, can potentially serve as a surrogate for both types of exposures. Recent studies proposed urinary 1- and 2-naphthol as possible biomarkers of PAH exposures through inhalation, but the lower yields of analytical techniques limited their comparison to 1-pyrenol, the widely accepted biomarker. A method was developed to simultaneously measure urinary naphthols and 1-pyrenol. Levels of urinary naphthols were measured in samples obtained from workers exposed to different levels of PAHs (coke oven workers) and JP-8 (U.S. Air Force personnel) based on a priori exposure categories. Multivariate linear regression analyses were applied to evaluate the effects of environmental and work-related factors upon naphthol levels. Results confirm the expectations that urinary naphthols are predictive of naphthalene exposures originating from different mixtures, and that coke oven emissions are much greater sources of naphthalene exposure compared to JP-8. However, smokers and nonsmokers appear to have different patterns of naphthalene metabolism, suggesting that cigarette smoke induces two or more metabolic pathways.