An integrated health risk assessment of contaminated sites under aleatory and epistemic uncertainties
An integrated health risk assessment framework including contaminant transport model, exposure assessment models, physiologicallybased pharmacokinetic (PBPK) modelling, and dose-response assessment was developed in this paper to bridge the gap amongst environmental engineers, toxicologists, and researchers in environmental health science and to improve the comprehensive understanding of the health risks posed by contaminated sites. Aleatory and epistemic uncertainties are identified, properly represented and coupled into the presented framework. The results show that: 1) the propagation of aleatory and epistemic uncertainties through the framework is transparent; 2) contaminant plume detection time (DT) or starting exposure time (SET) influence the final risk assessment; 3) for life time risk (e.g., exposure time equals 30 years), the steady state PBPK models are sufficient; 4) the total risk estimated using a point estimation method is higher by one to three orders of magnitude than that obtained from the integrated assessment framework.
Keywords: integrated health risk assessment, contaminated sites, uncertainty representation, uncertainty propagation, fuzzy sets, probability theory, physiologically-based pharmacokinetic modelling, aleatory uncertainties, epistemic uncertainties, transport models, exposure assessment, dose-response assessment, environmental health, health risks, contaminant plume detection, environmental pollution, fuzzy logic