Related Experiment Videos
Sensitivity and uncertainty analysis for Abreu & Johnson numerical vapor intrusion model
Jie Ma1, Guangxu Yan1, Haiyan Li1
1State Key Laboratory of Heavy Oil Processing, Beijing Key Lab of Oil & Gas Pollution Control, University of Petroleum-Beijing, Beijing 102249, China; College of Chemical Engineering, University of Petroleum-Beijing, Beijing 102249, China.
Journal of Hazardous Materials
|December 1, 2015
Summary
Sensitivity and uncertainty analyses reveal key vapor intrusion model parameters vary with source depth and concentration. Deep, low-concentration sources show higher uncertainty driven by soil properties and biodegradation.
Area of Science:
- Environmental Science
- Geology
- Chemical Engineering
Background:
- Vapor intrusion is a significant exposure pathway for indoor air contamination.
- Numerical models are crucial for assessing vapor intrusion risks.
- Understanding model sensitivity and uncertainty is vital for accurate risk assessment.
Purpose of the Study:
- To perform a one-at-a-time (OAT) sensitivity and uncertainty analysis on a numerical vapor intrusion model.
- To identify key input parameters influencing model output across various scenarios.
- To evaluate the impact of source characteristics on model sensitivity and uncertainty.
Main Methods:
- Conducted OAT sensitivity and uncertainty analysis for nine input parameters.
- Simulated vapor intrusion for three soil types, two source depths, and two source concentrations.
- Analyzed parameter influence on model output under different conditions.
Main Results:
- Model sensitivity and uncertainty are significantly lower for shallow, high-concentration sources compared to deep, low-concentration sources.
- For high-concentration sources, soil air permeability, indoor air exchange rate, and building depressurization are critical uncertainty drivers.
- For low-concentration sources, soil porosity, soil moisture, aerobic biodegradation rate, and soil gas permeability are key uncertainty drivers.
- Aerobic biodegradation's impact on petroleum hydrocarbon vapor intrusion is negligible at high source concentrations due to oxygen limitation.
Conclusions:
- The relative importance of input parameters in vapor intrusion models is highly dependent on source characteristics (depth and concentration).
- Site-specific conditions and source properties must be considered for accurate vapor intrusion risk assessment.
- Understanding parameter uncertainty is crucial for prioritizing mitigation strategies and reducing exposure risks.