Historical control data for the interpretation of ecotoxicity data: are we missing a trick?

Area of Science:

• Environmental toxicology and chemical risk assessment.
• Wildlife ecotoxicology study design and data interpretation.

Background:

• Wildlife are exposed to anthropogenic chemicals, necessitating ecotoxicity studies to assess risks.
• Ecotoxicity study results exhibit variability, making it difficult to distinguish true effects from background noise.
• Historical control data (HCD) are used in mammalian toxicology but underutilized in ecotoxicology.

Purpose of the Study:

• To advocate for the improved use of historical control data (HCD) in ecotoxicology.
• To illustrate the value and challenges of employing HCD in interpreting ecotoxicity study results.
• To encourage regulatory bodies to develop guidance for HCD collection and application.

Main Methods:

• Discussion of the rationale and potential barriers to HCD implementation in ecotoxicology.
• Case studies demonstrating the application of HCD in standard and higher-tier ecotoxicity study designs.
• Analysis of reasons for HCD's limited use in ecotoxicology compared to mammalian toxicology.

Main Results:

• HCD can provide valuable context for interpreting ecotoxicity data, aiding in distinguishing treatment effects from natural variability.
• Challenges in HCD use include data type differences, potential masking of effects, and lack of standardized guidance.
• Despite challenges, HCD offers a scientifically valid and ethical approach to chemical risk assessment.

Conclusions:

• Enhanced utilization of HCD in ecotoxicology is scientifically sound and ethically important for minimizing vertebrate testing.
• Development of standardized guidance for HCD collection by organizations like OECD, EFSA, and USEPA is recommended.
• Increased regulatory acceptance and use of HCD can lead to more robust and reliable chemical risk assessments.