Trophic Trace and the Bioaccumulation Risk Assessment Modeling System (BRAMS):
A tool for estimating risks from bioaccumulation of sediment associated contaminants

U.S. Army Corps of Engineers | Engineer Research and Development Center | Environmental Laboratory | Search EL


POC: Igor Linkov, Ph.D., and Todd Bridges, Ph.D.

brams-1 The Bioaccumulation Risk Assessment Modeling System (BRAMS) is an executable program that can be used to calculate, with inputs provided by users, potential human health and ecological risks due to bioaccumulation of sediment-associated contaminants. It contains two separate tools, Trophic Trace (TT) and the Bioaccumulation Evaluation Screening Tool (BEST), which use separate equations and inputs to calculate risks. The program is designed to provide health- and ecologically-protective estimates of potential risk using results from sediment chemistry tests and/or 28-day bioaccumulation tests. Users can create new models or edit inputs in an established template model based on different trophic structures, human and ecological exposure scenarios and site-specific conditions. The algorithms incorporated into BRAMS follow USEPA and USACE risk assessment guidance (USEPA, 1989; 1997a; USEPA/USACE, 1998; Cura et al., 1999). Use of BRAMS to evaluate the risks posed by a specific sediment or site must be based on appropriate, site-specific inputs.

The implemented Trophic Trace 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. Trophic Trace model outputs include total carcinogenic and non-carcinogenic risks to humans and NOAEL and LOAEL toxicity quotients for ecological receptors as well as risks from specific chemicals and dietary species. Trophic Trace 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 Trophic Trace for demonstration purposes only. The stand-alone version of Trophic Trace was updated and recoded for the version implemented within BRAMS. The version of Trophic Trace contained within BRAMS follows the same technical framework and retains all the functionality of the stand-alone version of TrophicTrace 4.1.

The Bioaccumulation Evaluation Screening Tool (BEST) estimates expected risks to human receptors by (1) calculating the edible tissue concentration in human diet species including invertebrate test organisms and their predators based on results of 28-day bioaccumulation testing, (2) calculating an average daily dose to humans that consume these species, and (3) using standard EPA risk equations to determine potential carcinogenic and non-carcinogenic risks. The BEST reports displays risk results for dredged sediments compared side-by-side with reference site risks, and acceptable risk thresholds. Calculated tissue concentrations are also compared to FDA action levels and ecological effects levels.

brams-2 There are 4 items available for download: The BRAMS setup folder (includes the executable java program (BRAMS.jar), Users Manual, and Microsoft Excel input templates), the BRAMS Users Manual, a BRAMS Presentation describing the program’s scope, background, and technical framework, and a Management Guide developed for TrophicTrace 4.1 that is applicable to the Trophic Trace component of BRAMS and provides program-specific guidance to Corps dredged material managers.

Users are invited to provide feedback to the POCs on any aspect of BRAMS and its functionality. This input will be considered during development of future updates.



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Webdate: February 5, 2003
Updated: August 2012