MODEXMO: A modular non-dietary exposure assessment approach for pesticides using dose-based dermal absorption prediction

Abstract

A modular non-dietary exposure assessment approach for pesticides (PPPs) is proposed, emphasizing a dose-based prediction of dermal absorption. The Modular Dermal Exposure Model (MODEXMO) defines new nomenclature: exposure, dermal absorption and surface distribution prediction models, respectively abbreviated as EXPREMOs, DAPREMOs, SUDIPREMOs. Approach and nomenclature are generic and can be used for probabilistic models or simulation-based approaches. The modularity aids the integration of refined exposure data and enhances the adaptability of risk assessments to better reflect dynamic real-world scenarios. DAPREMOs could replace relative dermal absorption values (DAVs) by directly predicting internal exposure from external doses with a statistical model. It is well-known that absolute dermal penetration depends primarily on applied dose. EXPREMOs can predict relatively low area doses, since exposure estimates are averaged over large body surfaces, regardless of the actual residue surface distribution. While this has no consequence in the current assessment approach using DAVs, it ignores the exposure scenario-dependent spatial distributions of residue on skin, e.g., due to individual splash events during mixing and loading operations. SUDIPREMOs can refine EXPREMO-assumed default surface areas to provide DAPREMOs with more accurate inputs for different area doses in multiple exposure sub-streams.