Introduction: Occupational exposure to the BTEX compounds (Benzene, Toluene, Ethylbenzene, and Xylene) in the printing industry is a major health concern due to their established carcinogenic and non-carcinogenic toxicity. This study aimed to quantify respiratory exposure, assess the internal biological dose, and determine the associated carcinogenic and non-carcinogenic health risks using the US-EPA methodology.
Methods: This cross-sectional study monitored 23 occupationally exposed printing workers and 23 unexposed administrative staff (control group). Personal respiratory air sampling was conducted for BTEX (NIOSH 1501/GC), and end-of-shift urine samples were collected for biological monitoring of t,t-MA (Benzene metabolite) and Hippuric Acid (Toluene metabolite) using HPLC. Health risks were calculated using the EPA guidelines for the Hazard Quotient (HQ) and Lifetime Cancer Risk (LCR).
Results: The Mean BTEX concentrations were high, notably toluene (47.17±52.03 ppm) and xylene (45.12±68.41 ppm) were markedly elevated. Biological monitoring revealed statistically significant differences between the groups (p < 0.001); the mean t,t-MA level in the exposed group was 51,809.37 µg/g creatinine compared to 265.75 µg/g creatinine in the control group. Risk assessment indicated critical non-carcinogenic risks, with HQs for Xylene (230.06), Benzene (16.43), and Toluene (8.35) far exceeding the safety threshold of 1. The mean LCR for Benzene was 7.8×10⁻³, significantly surpassing the EPA acceptable limit of 10^-6.
Conclusion: Chronic BTEX exposure in this printing facility significantly exceeded the permissible occupational limits, resulting in substantial non-carcinogenic and carcinogenic risks. Immediate intervention through engineering controls and comprehensive revision of safety standards is urgently required to protect worker health.