P-206 Exposure Assessment in Occupational Settings: Importance of an Adapted Biomonitoring Strategy

Abstract Introduction The investigation of hygiene samples is often insufficient to evaluate the health risks due to occupational exposure. Human biomonitoring (HBM) is an important tool to determine directly the concentrations of substances or their metabolites in the body. In this context, we investigated workers exposed to volatile organic compounds (VOCs) in an occupational setting by means of HBM in urine, integrated with air exposure measurements. Methods Exposed workers (n=57) were recruited during the remediation works in an old industrial site polluted by VOCs, from December 2019 until June 2020. Pre-shift and post-shift urine samples were collected together with continuous air monitoring for total VOCs using PIDs. Urinary concentration of methylhippuric acid; S-phenyl mercapturic acid; muconic acid; mandelic acid; phenylglycoxylic acid; trichloroacetic acid; o-cresol acid; hippuric acid were determined. Information about the performed tasks and personal protective equipment (PPEs) were also collected. Results The concentration of o-cresol were lower in the period before Covid-19 outbreak, ranging from 0.08 to 0.51 mg/gcreat, while, after the Covid-19 restriction, the concentration ranged from 0.34 to 0.55 mg/gcreat. However, the analyses of air samples have shown a higher VOCs concentration (1.72 – 33.98 ug/m3) in the first period, compared with the second period (1.5 – 12.03 ug/m3). Discussion In this study, it has been observed that concentrations of urine metabolites were highly related with exposure. These findings have been associated with an improper use of PPEs. Conclusion This study highlights the importance of HBM and its utility in better determining the absorbed dose compared with the more conventional environmental assessment.