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Split Point Analysis and Uncertainty Quantification of Thermal-Optical Organic/Elemental Carbon Measurements
Published on: September 7, 2019
Separation of uncertainty and interindividual variability in human exposure modeling
Ad M J Ragas1, Femke P E Brouwer, Frederike L Büchner
1Department of Environmental Science, Radboud University Nijmegen, Nijmegen, The Netherlands. a.ragas@science.ru.nl
Journal of Exposure Science & Environmental Epidemiology
|April 10, 2008
Summary
The NORMTOX model assesses contaminant exposure risks. Dutch populations face exceeding acceptable daily intake (ADI) for chlorfenvinphos and mercury when environmental standards are met, highlighting the need to identify at-risk groups.
Area of Science:
- Environmental Health Risk Assessment
- Toxicology
- Environmental Science
Background:
- Environmental quality objectives (EQOs) aim to limit contaminant exposure.
- Coherence testing ensures meeting EQOs doesn't lead to exceeding acceptable daily intake (ADI) or tolerable daily intake (TDI).
- The NORMTOX model evaluates lifetime-averaged exposure across multiple environmental media.
Purpose of the Study:
- To differentiate the effects of uncertainty and interindividual variability on NORMTOX model predictions.
- To assess the coherence of Dutch EQOs for specific contaminants.
Main Methods:
- Analysis of Variance (ANOVA) to quantify interindividual variability in input parameters.
- Nested Monte Carlo simulation to separately propagate uncertainty and variability.
- Modeling lifetime-averaged exposure for the Dutch population for chlorfenvinphos, mercury, and nitrate.
Main Results:
- 100% of the Dutch population exceeds the ADI for chlorfenvinphos, 15% for mercury, and 0% for nitrate under simulated conditions.
- Interindividual variability, not uncertainty, is the primary driver of exposure variance for these contaminants.
- The NORMTOX model identified significant risks associated with current environmental quality standards.
Conclusions:
- The coherence of EQOs for chlorfenvinphos and mercury is questionable, necessitating further investigation.
- Decision-making should prioritize identifying high-risk subpopulations rather than solely pursuing more precise parameter estimations.
- Environmental risk assessment models are crucial for evaluating public health impacts of pollution standards.
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