8291316 Aggregate exposure assessment of PFAS in occupational settings: case studies on ski waxers and chemical plant workers

<h3>Objective</h3> Chemical exposure can result from multiple routes and sources, including those encountered in the workplace. This study aims to develop and apply a methodology for assessing aggregate exposure to perfluoroalkyl substances (PFAS) in the workplace. By integrating multi-route exposure data, the approach identifies key contributors to internal PFAS concentrations in selected occupational groups. Additionally, it aims to streamline fragmented exposure information, address critical data gaps, and improve alignment with predictive models to support more effective risk assessment. <h3>Methods</h3> Ski wax technicians and chemical plant workers, two occupations with high potential for PFAS exposure, were selected as case studies based on the availability of measurement data and suitable exposure models. External exposure to perfluorooctanoic acid (PFOA) via inhalation and dermal contact was modeled for typical workday scenarios using the Advanced REACH Tool (ART) and dermal ART (dART). These modeled exposures were compared to available measurement data. Combined with background oral intake from daily life, the results were used to estimate serum PFOA concentrations using a physiologically based pharmacokinetic (PBPK) model and compared to human biomonitoring (HBM) data. <h3>Results</h3> In both case studies, inhalation exposure alone underestimated serum concentrations. To address data gaps such as missing task details, fragmented exposure information was integrated and supplemented with assumptions based on similar scenarios. The aggregate exposure approach resulted in serum concentration estimates that aligned well with available HBM data, supporting the methods validity. <h3>Conclusion</h3> This study demonstrates the importance of aggregate exposure assessment for PFAS in occupational settings. Considering multiple exposure routes provides a more comprehensive view than single-route assessments, facilitates better interpretation of biomonitoring data, and supports more targeted and effective exposure control strategies.