Dr. Williams recently completed a review of 35 exposure assessment models currently used and supported by the U.S. Environmental Protecton Agency.  These models represent the first half of the source-to-outcome continuum and include 12 fate/transport models, 5 exposure models, and 8 integrated fate/transport and exposure models.  Although most of these models were developed to assess exposures to the general public, some were developed (or can be used) to assess exposures in occupational settings.  Each model is summarized with respect to its intended purpose and potential applications, level of analysis and routes of exposure, key data inputs and exposure/risk outputs, temporal and spatial resolution, treatment of variability and uncertainty, degree of model evaluation, level of internal and external peer review, and interactions with other models.  This information provides a useful up-to-date resource for exposure and risk modelers and practitioners.

Dr. von Stackelberg served as Project Manager and technical lead for the development of FishRand, a two-dimensional probabilistic bioaccumulation model originally developed to support decision making at the Hudson River Superfund Site. Subsequently, on behalf of the Army Corps of Engineers, Dr. von Stackelberg led the effort to augment FishRand by including a spatially-explicit exposure component to capture the effects of fish foraging and migration strategies on exposure.  The model incorporates a GIS-“lite” allowing users to specify shape-based areas of contamination on a map.  The model is available as part of the Adaptive Risk Assessment Modeling System.

www.erdc.usace.army.mil/pls/erdcpub/www_welcome.navigation_page?tmp_next_page=51483

TrophicTrace allows users to quickly and easily estimate potential human health and ecological risks due to bioaccumulation of sediment-associated contaminants. The model estimates expected concentrations in fish using a sediment-based food-web model for organic compounds, via trophic transfer factors from invertebrates to fish for certain metals, and via bioconcentration factors from water to fish for the remaining metals and hydrophilic organic compounds. Risks are calculated following USEPA and USACE risk assessment guidance. TrophicTrace allows users to characterize the uncertainty associated with risk estimates using trapezoidal fuzzy numbers. Uncertainties can be propagated using fuzzy arithmetic principles that provide risk estimates in the form of trapezoidal fuzzy numbers. Example data sets are provided within TrophicTrace for demonstration purposes only. Use of TrophicTrace to evaluate the risks posed by a specific sediment or site must be based on appropriate, site-specific inputs.

http://www.wes.army.mil/el/trophictrace/index.html
http://el.erdc.usace.army.mil/trophictrace/
http://environ.spawar.navy.mil/Links/modeling.html