Argumentation Analysis of Risk Assessments: The Case of Perfluorooctanoic Acid

Area of Science:

• Environmental Science
• Toxicology
• Risk Assessment

Background:

• Chemical risk assessment relies on toxicology and epidemiology, potentially yielding different health-based guidance values (HBGVs).
• Clear communication of the rationale behind data selection is crucial for public and policymaker understanding.
• Perfluorooctanoic acid (PFOA) serves as a case study to examine argumentation in HBGV derivation.

Purpose of the Study:

• To analyze the argumentation justifying the use of toxicological versus epidemiological data in PFOA risk assessments.
• To apply pragma-dialectical argumentation theory (PDAT) to understand the reasoning behind HBGV derivations.
• To identify weaknesses in the current argumentation structures within chemical risk assessments.

Main Methods:

• Analysis of four PFOA risk assessments using pragma-dialectical argumentation theory (PDAT).
• Examination of how health endpoints and causality inferences are justified.
• Evaluation of the explicit and implicit starting points in the argumentation chains.

Main Results:

• Argumentation for data selection often relies on 'symptomatic relations' without detailing causal mechanisms.
• Underlying assumptions and causal reasoning are frequently implicit or not fully addressed.
• Decisions to include or exclude data are often based on availability, with unclear motives.
• The justification for using specific toxicological or epidemiological data is often minimally presented.

Conclusions:

• Risk assessments require more in-depth argumentation and clearer chains of reasoning to disclose the basis for HBGVs.
• Explicitly identifying and discussing the starting points of arguments can enhance risk assessment frameworks.
• Greater transparency in argumentation can lead to better utilization of toxicological and epidemiological data and more consensus.