Title: An integrated health risk assessment of contaminated sites under aleatory and epistemic uncertainties

Authors: Kejiang Zhang, Gopal Achari, Hua Li, Harvey J. Clewell III

Addresses: Department of Civil Engineering, University of Calgary, 2500 University Drive NW, Calgary, Alberta, T2N 1N4, Canada. ' Department of Civil Engineering, University of Calgary, 2500 University Drive NW, Calgary, Alberta, T2N 1N4, Canada. ' Department of Mathematics, Zhengzhou University, Science Road 100, Zhengzhou, Henan, 450001, China. ' The Hamner Institutes for Health Sciences, 6 Davis Drive, P.O. Box 12137, Research Triangle Park, NC 27709, USA

Abstract: 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.

DOI: 10.1504/IJRAM.2011.041002

International Journal of Risk Assessment and Management, 2011 Vol.15 No.1, pp.4 - 42

Published online: 28 Feb 2015 *

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