Distributional analyses for children's inhalation risk assessments

Area of Science:

• Environmental Health Sciences
• Toxicology
• Risk Assessment

Background:

• Current risk assessments utilize point-estimate "uncertainty factors" or "adjustment factors" to derive reference doses (RfDs) and reference concentrations (RfCs).
• These factors often represent underappreciated aspects of variability and uncertainty with significant implications for risk analysis structure.

Purpose of the Study:

• To propose a novel methodology for enhancing the quantitative understanding of variability and uncertainty in risk assessments.
• To introduce the concept of building databases of analogous cases to represent current uncertainty factors.

Main Methods:

• Developing databases of putative analogous cases to systematically represent variability and uncertainty.
• Illustrating the application of these databases with preliminary comparisons of child and adult population variability in activity and respiratory parameters.

Main Results:

• Demonstrated the potential for databases to provide a more quantitative basis for understanding variability and uncertainty compared to traditional factors.
• Preliminary comparisons highlight differences in child and adult population variability relevant to risk assessment.

Conclusions:

• Advocates for a shift towards data-driven databases for a more robust quantitative assessment of variability and uncertainty.
• Suggests this approach can refine the estimation of risk, particularly concerning population differences.