Urinary 1-Hydroxypyrene as an Indicator for Assessing the Exposures of Booth Attendants of a Highway Toll Station to Polycyclic Aromatic Hydrocarbons

In this study, 32 booth attendants (the exposure group) and 21 in pre-job training to become booth attendants (the reference group) were randomly selected from a highway toll station. Personal PAH samplings were conducted on the exposure group on each day during the studied workweek. Pre-shift urinary 1-hydroxylpyrene levels (1-OHP) were measured on the first day of the workweek (BM_pre) for both the exposure and reference groups, but the post-shift 1-OHP levels were measured on the last day of the workweek (BM _post) only for the exposure group. For the exposure group, we found that their mean total PAH exposure level (C_{total PAHs}) was 11 400 ng/m³ and that their mean BM_post was significantly higher than their mean BM_pre (= 3.02 and 0.910 μmol of 1-OHP/mol of creatinine, respectively). In addition, the mean BM_pre for the exposure group were higher than that for the reference group (= 0.410 μmol of 1-OHP/mol of creatinine). The above results suggest that vehicle exhaust significantly affects the booth attendants' 1-OHP levels. None of the three personal factors (age, work experience, and smoking habit), except for C _{total PAHS}, had a significant effect on predicting booth attendants' BM_inc levels (= BM_post - BM_pre) (R² = 0.57). The above results suggest that urinary 1-OHP could be a suitable biomarker for characterizing workers' PAH exposures. Similarly, we found that none of the three personal characteristics, except for the involved vehicle flow rates and vehicle types, had a significant effect on predicting booth attendants' BM_inc levels (R² = 0.60). The above result suggests that the traffic densities of various traffic types could be a suitable surrogate indicator for assessing workers' PAH exposures. Considering that the type of traffic designed for a given type of tollbooth is quite similar all over the world, the results obtained from this study, at least, could be served as a stepping-stone for providing a cheaper and convenient way for assessing traffic PAH exposures in the future.