Environmental Risk Assessment with Energy Budget Models: A Comparison Between Two Models of Different Complexity.

Area of Science:

• Environmental toxicology
• Ecological risk assessment
• Chemical safety

Background:

• Extrapolating laboratory chemical effects to real environments is a key challenge in ecological risk assessment (ERA).
• Toxicokinetic-toxicodynamic (TKTD) models, derived from dynamic energy budget (DEB) theory, offer a solution for bridging this gap.
• The impact of TKTD model complexity on regulatory ERA remains unclear.

Purpose of the Study:

• To compare the performance of two DEB-TKTD models with varying complexity levels.
• To evaluate model calibration using standard test data and forward predictions under time-variable exposures.
• To inform the selection of appropriate TKTD models for chemical risk assessment.

Main Methods:

• Utilized two DEB-TKTD models: a standard DEB model with primary parameters and a reduced DEBkiss model with compound parameters.
• Harmonized modeling choices for consistent comparison.
• Calibrated models on standard toxicity test data and performed forward predictions for untested exposure scenarios.

Main Results:

• Both DEB-TKTD models demonstrated comparable performance in calibration and forward prediction steps.
• Model complexity did not significantly differentiate predictive accuracy within current pesticide ERA procedures.
• Model selection for ERA should consider the balance between ease of use and flexibility.

Conclusions:

• The choice between complex and simplified DEB-TKTD models for ERA may hinge on practical considerations like usability and flexibility rather than solely on predictive performance.
• Emphasized the critical role of informed modeling choices, including data gap imputation and harmonization of growth/reproduction data.
• Further research is needed to refine TKTD model selection criteria for robust ecological risk assessment.