P-341 Comprehensive Evaluation of Carcinogenic Biomarkers: Urinary 1-Hydroxypyrene Is the Most Effective Marker of Polycyclic Aromatic Hydrocarbons Exposure

Introduction Polycyclic aromatic hydrocarbons (PAHs) include many carcinogens. We conducted a cross- sectional study in a steel plant to identify biomarkers that reflect the carcinogenicity of PAHs. Methods Subjects were 57 workers and 20 controls. Personal exposure levels were measured using GC-MS, and urinary metabolites were treated with β-glucuronidase followed by High Performance Liquid Chromatography analysis with fluorescence detection. Results and Discussion Personal exposure levels to 15 PAHs (Total-PAHs) ranged from 47.08 to 1,329.45 µg/m3, with a mean of 178.85 µg/m3 (geometric mean, 5th, and 95th percentile). Analysis of urinary metabolites detected 10 known compounds, including 1-hydroxynaphthalene, 2-hydroxynaphthalene, 2-hydroxyfluorene, and others, along with four unknown peaks. The highest correlation was found between Total-PAHs and urinary 2- hydroxynaphthalene (Spearman r = 0.716, P < 0.01). Notably, urinary 2-hydroxyfluorene, 1-hydroxyphenanthrene, 3-hydroxyphenanthrene, and 1-hydroxypyrene showed significant correlations with the “Σ carcinogenic potency of PAHs,” with the most significant association observed for 1-hydroxypyrene (Spearman r = 0.630, P < 0.01). Conclusions Urinary 1-hydroxypyrene was identified as the most comprehensive carcinogenic biomarker for assessing PAH exposure. This study emphasizes the importance of monitoring PAH exposure levels and their potential health risks among steel plant workers.