An Overview of a Multimedia Benchmarking Analysis for Three Risk Assessment Models: RESRAD, MMSOILS, and MEPAS

Abstract

Multimedia modelers from the United States Environmental Protection Agency (EPA) and the United States Department of Energy (DOE) collaborated to conduct a detailed and quantitative benchmarking analysis of three multimedia models. The three models--RESRAD (DOE), MMSOILS (EPA), and MEPAS (DOE)--represent analytically-based tools that are used by the respective agencies for performing human exposure and health risk assessments. The study is performed by individuals who participate directly in the ongoing design, development, and application of the models. Model form and function are compared by applying the models to a series of hypothetical problems, first isolating individual modules (e.g., atmospheric, surface water, groundwater) and then simulating multimedia-based risk resulting from contaminant release from a single source to multiple environmental media. Study results show that the models differ with respect to environmental processes included (i.e., model features) and the mathematical formulation and assumptions related to the implementation of solutions. Depending on the application, numerical estimates resulting from the models may vary over several orders-of-magnitude. On the other hand, two or more differences may offset each other such that model predictions are virtually equal. The conclusion from these results is that multimedia models are complex due to the integration of the many components of a risk assessment and this complexity must be fully appreciated during each step of the modeling process (i.e., model selection, problem conceptualization, model application, and interpretation of results).

Combining the cost of reducing uncertainty with the selection of risk assessment models for remediation decision of site contamination

“…It has been shown that besides comparing model predictions with observations, the magnitude of model uncertainty can be determined by the range of results among several models [6,17,19]. Therefore, many studies have performed model comparisons to investigate the differences among models; in particular, a series of papers compared MEPAS, MMSOILS, and RESRAD [20][21][22][23]. Table 1 The representative classifications of uncertainty in the literature Finkel [5] USEPA [6] Cullen and Frey [8] Parameter Through simulating several cases, these studies have observed obvious differences, which are as large as two or even three orders of magnitude, of risk estimates in various models due to different environmental processes considered, mathematical formulations used, and scenario assumptions made.…”

“…These models are also designed for screening-level tools and site-specific risk assessments for regulatory development and standard setting [20]; however, the different environmental processes considered, mathematical formulations used, and scenario assumptions made in these models will cause different results, and thus model uncertainty. The scenario considered in this case study is that the residents use groundwater for irrigation and domestic purposes.…”

Comparative study of multimedia models applied to the risk assessment of soil and groundwater contamination sites in Taiwan

“…More details of MEPAS and MMSOILS and their application can be found elsewhere [7,[9][10][11][12][13].…”

A set of software components for the simulation of plant airborne diseases

“…source pollution loads (Argent, 2005), the impact of agricultural management practices (e.g., Donatelli et al, 2006), simulation of water soil dynamics (Leavesley et al, 1996), and the qualitative aspects of crop production (Cappelli et al, 2014). Given that most environmental problems benefit from a multidisciplinary analysis (Whelan et al, 2014), the availability of framework-independent software components strongly fosters the development of modelling solutions that integrate single-discipline approaches (Laniak et al, 1997;Donatelli et al, 2014).…”