Endogenous Lifecycle Models for Chemical Risk Assessment.

Area of Science:

• Ecotoxicology
• Ecological modeling
• Chemical risk assessment

Background:

• Population models have been researched for chemical risk assessment for over 50 years.
• The practical utility of traditional population models in risk assessment remains limited due to complexity and cost.

Purpose of the Study:

• To propose a novel application and interpretation of Endogenous Lifecycle Models (ELMs) for chemical risk assessment.
• To offer benefits of population models at a reduced cost of design, parameterization, and verification.
• To develop robust qualitative predictions of chemical effects across diverse avian lifecycles.

Main Methods:

• ELMs integrate endogenous lifecycle processes: growth, development, survival, and reproduction.
• Fitness is estimated and predicted using two key measures: lifetime reproductive success and intrinsic fitness.
• Model predictions are designed to be qualitative and robust, minimizing reliance on specific parameter values.

Main Results:

• Two ELM examples are presented: one for a general passerine and another for bald eagles (Haliaeetus leucocephalus).
• The ELM approach prioritizes generality over precision to understand chemical effects across varied avian lifecycles.
• ELMs integrate with the adverse outcome pathway framework for midtier risk assessment.

Conclusions:

• ELMs provide a practical and cost-effective alternative to traditional population models in ecotoxicology.
• The approach yields robust qualitative predictions applicable to diverse avian species.
• Integration with the adverse outcome pathway framework enhances ELMs' utility in tiered risk assessment strategies.