Assessment of anxiety risk association with PAHs and aluminum co-exposure in an aluminum production facility

BACKGROUND: Workers in aluminum production plants are occupationally exposed to polycyclic aromatic hydrocarbons (PAHs), including the neurotoxicant benzo[a]pyrene (BaP), as well as to aluminum dust and fumes. While the physical health effects are established, the psychological impact, particularly on anxiety, remains less explored. This study investigated the associations of urinary 1-hydroxypyrene (1-OHP), a biomarker of PAHs exposure, and urinary aluminum levels with anxiety symptoms in aluminum workers. METHODS: In this cross-sectional study, 260 participants (130 exposed workers and 130 controls) from an aluminum plant were enrolled. Urinary aluminum concentration was measured using inductively coupled plasma mass spectrometry (ICP-MS). Anxiety was assessed using the Beck Anxiety Inventory (BAI), and job stress was evaluated using the Job Content Questionnaire (JCQ). BaP exposure was assessed using personal air sampling following NIOSH Method 5515. Urinary 1-OHP levels were quantified using high-performance liquid chromatography (HPLC). Group comparisons, Pearson correlation, and multiple linear regression analyses were performed using SPSS software version 22. RESULTS: The exposed group had significantly higher anxiety scores (10.74 ± 6.18) than the control group (8.88 ± 5.28). Urinary aluminum concentration was significantly higher in the exposed group (33.45 ± 16.20 µg/g creatinine) compared to controls (7.35 ± 3.99 µg/g creatinine). In the final regression model, which included total job stress as an independent variable alongside age, job experience, and smoking, urinary 1-OHP (β = 0.204), urinary aluminum (β = 0.177), smoking (β = 0.202), and total job stress (β = 0.295) were all significantly associated with anxiety, explaining 38.4% of the variance (R² = 0.384). CONCLUSION: The internal dose of PAHs, measured via urinary 1-OHP, and aluminum body burden, measured via urinary aluminum, are significantly associated with higher anxiety symptoms. Notably, job stress also independently was associated with anxiety in this cohort. This highlights the potential neurotoxic impact of combined PAH and aluminum exposure on mental health and suggests the need for integrated psychological and biological monitoring in high-risk occupations.