Evaluation of the Inherent Toxicity Concept in Environmental Toxicology and Risk Assessment

Area of Science:

• Toxicology
• Environmental Science
• Biochemistry

Background:

• Toxicity is an extrinsic property dependent on molecular dose, not an intrinsic chemical characteristic.
• Paracelsus's principle highlights that dose determines poisonous effects, challenging the view of toxicity as a fixed property.
• Current hazard-based approaches inadequately address variability in experimental toxicity data.

Purpose of the Study:

• To propose a shift from hazard-based to a standard-risk, case-specific risk model in toxicology.
• To emphasize the need for understanding dose-causality-response relationships for accurate risk assessment.
• To highlight the inadequacy of current knowledge for translating standard risks to specific risks.

Main Methods:

• Critically evaluating the definition of toxicity as an intrinsic versus extrinsic property.
• Proposing a standard-risk, case-specific risk model as an alternative to hazard-based approaches.
• Advocating for a focus on dose-causality-response to improve toxicity testing and interpretation.

Main Results:

• Toxicity is fundamentally a function of dose magnitude, making it an extrinsic property.
• Experimental toxicity data exhibit significant variability, undermining fixed-property assumptions.
• A standard-risk, case-specific risk model offers a logical framework for risk assessment.

Conclusions:

• Moving towards a standard-risk, case-specific risk paradigm is essential for advancing regulatory risk decision-making.
• Improving the knowledge base on toxicity causality is crucial for accurate risk assessment.
• Enhanced toxicity testing design and interpretation are needed to translate standard risks to specific risks effectively.