Characterizing paraben exposure and source contributions in Korea: A personalized exposure factor-based approach (PerFactExpo).

Parabens are widely used preservatives with diverse exposure pathways across diet and personal care products (PCPs). Although a comprehensive exposure assessment is essential for effective exposure management, it remains highly challenging. Conventional exposure assessment methods that rely on representative contamination levels and standard exposure factors often produce overly conservative high-end estimates, particularly for reasonable maximum exposure (RME). To address these limitations, we developed the Personalized Exposure Factor-Based Exposure Assessment (PerFactExpo) model, which integrates individual-level dietary and product-use data from national databases to estimate aggregate paraben exposure in the Korean population. To evaluate the model's performance, deterministic central tendency exposure (CTE) and RME estimates were compared directly with the corresponding individual-based PerFactExpo estimates. While CTE estimates from the PerFactExpo model were comparable to those from the deterministic approach, its RME estimates were up to 7.6-fold lower, demonstrating a substantial reduction in the inflation of upper-bound exposure estimates. The plausibility of the exposure sources identified by the model was supported by their general consistency with national biomonitoring data. PCPs predominantly drove methyl-, propyl-, and butylparaben exposure, particularly in females, whereas ethylparaben exposure was primarily associated with traditional fermented soy-based condiments. These findings suggest that imported mustard products may contribute to PrP exposure; however, product-origin-specific concentration data are warranted to confirm this interpretation. These findings demonstrate the utility of this personalized, aggregate multi-source exposure assessment framework for identifying major exposure contributors and offering insights for developing targeted exposure reduction strategies for such widely used consumer chemicals.