Using the standard DEB animal model for toxicokinetic-toxicodynamic analysis

Toxicokinetic-toxicodynamic (TKTD) models are essential tools to close the gap between laboratory toxicity tests and impacts on individuals under field conditions. For sub-lethal effects on life-history traits, dynamic energy budget (DEB) theory provides a solid basis for TKTD modelling. Various DEB-based TKTD models have been presented, ranging from complex and comprehensive to simple and reduced. Here we present a complete and up-to-date model formulation at the complex end of the range. The basic part of the model, governing the life cycle of the species without toxicant stress, is formed by the standard DEB animal model. This part can directly use the species-specific model parameters from the add-my-pet (AmP) library. Additionally, we cover one extension of the standard model with metabolic acceleration for some time after birth (the abj-model). The basic DEB model is augmented by a TKTD model that explicitly considers damage as driving force for the toxic effects, and which considers various feedbacks from life-history traits to damage dynamics (e.g., dilution by growth). Several choices are needed in this linkage, which are made explicit. A Matlab-based toolbox is presented to support the model analyses, which is illustrated with a case study for the springtail Folsomia candida exposed to chlorpyrifos in food.

Automated summary

Toxicokinetic-toxicodynamic (TKTD) models are important tools to bridge the gap between laboratory toxicity tests and field conditions. Dynamic energy budget (DEB) theory provides a solid foundation for TKTD modeling. This paper presents a complete TKTD model that includes a standard DEB animal model and a TKTD model that considers damage as the driving force for toxic effects.