Physiologically based toxicokinetic models in aggregate exposure: A review

This literature review explores the application of Physiologically Based Kinetic (PBK) models in aggregate exposure (AE) assessment across different chemical classes. It builds on the screening of 1119 publications and the identification of 40 relevant articles. The most frequently studied chemicals include volatile organic compounds and plant protection products, with metals, personal care products, persistent organic pollutants and plasticisers also represented. Most studies reported in this review are applied to human populations and build on human biomonitoring (HBM) data to enhance model reliability. However, some studies use animal models (primarily rat models) and apply cross-species extrapolation to the human AE scenario. Occupational exposure is taken into consideration as part of the AE scenario in a few studies. Many of the reviewed studies are designed in support of chemical risk assessment (CRA), illustrating the wide applicability of PBK models. The review discusses the joint role of HBM data and PBK model in AE scenarios, highlighting its importance for a reliable risk assessments. The studies identified and discussed in this review suggest a broad interpretation of AE. The diversity across case reported studies is attributed to varying interpretations and existing definitions of AE. Finally, the roles of forward and reverse dosimetry in refining AE assessments are discussed, highlighting their importance for future research. This scoping review provides a comprehensive overview of PBK model applications in addressing AE, serving as a valuable foundation for future research and development aimed at advancing human health protection towards the Next-Generation Risk Assessment (NGRA).