Introduction: Asphalt workers are potentially exposed to polycyclic aromatic hydrocarbons (PAHs). As some PAHs are classified as carcinogenic, the assessment of occupational exposure to these agents is of the utmost importance in preventing toxic effects.
Objectives: To assess exposure to PAHs by urinary 1-hydroxypyrene (1-OHPyr).
Methods: We studied 22 asphalt workers (14 smokers) and 5 control subjects (1 smoker). Multiple samples of urine (up to 4per subject) were collected at the end of the shift for the measurement of 1-OHPyr by LCMS/MS. Univariate and multivariate linear models for repeated measurements were used to evaluate the differences between groups and to identify the variables influencing of exposure.
Results: The median urinary excretion of 1-OHPyr in asphalt workers was low, but higher than that of control subjects (184 vs. <20 ng/L, or 106 vs. <20 ng/g creatinine, p < 0.001); cigarette smoking marginally increased 1-OHPyr in smoking asphalt workers in comparison to non-smokers (129 vs. 208 ng/L p= 0.09 or 94 vs. 121 ng/g creatinine, p = 0.06). The number of consecutive days at work significantly influenced the urinary excretion of l-OHPyr [+59% every day, CI: (2, 147), p = 0.04]. Subjects using paving machines had the highest exposure. A strong association between 1-OHPyr and urinary creatinine was observed.
Conclusions: urinary 1-OHPyr is a useful indicator of occupational exposure to low levels of PAHs, such as those found in the subjects studied; in using this biomarker it is recommended to collect urine samples at the end of the working week and to express levels of the biomarker corrected for urinary creatinine.