Impact/Purpose:

To improve the scientific understanding of the linkage between fish methylmercury and ambient mercury in the environment.

To complete a model for transformation and bioaccumulation of mercury than can be linked with models for atmospheric deposition and hydrology to yield a multimedia integrated modeling system capable of quantifying regional exposure to mercury.

To apply state of the art watershed and water body modeling to assess exposures to mercury for impacted aquatic ecosystems.

Description:

Mercury is released from a variety of sources and exhibits a complicated chemistry. The primary exposure pathway for humans and wildlife is the consumption of contaminated fish. The goal of this research is to provide the scientific information needed for EPA to assess and manage mercury risks. ERD?s research program seeks to understand the environmental cycling of the major speciated forms of mercury through watersheds and water bodies.

This task will evaluate mercury fate in aquatic systems in the same region to understand the variability in key cycling processes. Process understanding, including research funded by ORD STAR grants, will be incorporated into the development of aquatic and terrestrial models, and field and laboratory data will be used to characterize key model parameters.

In cooperation with other Federal, State, and local agencies, ERD will test and refine simulation modeling techniques in several prototype ecosystems (e.g., New England lakes, Cheyenne River Sioux Reservation ponds, Georgia river basins, Sudbury River, Massachusetts, and Minnesota lakes). ERD will add appropriate process descriptions elucidated by scientific studies published by STAR grantees or in the general scientific literature. The refined models will be documented and packaged for distribution to EPA, states, and the general technical community.

In cooperation with the Multimedia Integrated Modeling System (MIMS) development project, an appropriate set of watershed and water body mercury fate models will be linked with the regional atmospheric mercury model based on the Community Multiscale Air Quality (CMAQ) modeling framework. Code revisions or wrappers will be developed according to MIMS protocols to produce an integrated multimedia mercury modeling capability. The prototype multimedia model will be tested on local and regional datasets in order to provide information on structural and parameter uncertainty to the continuing model development process. The case studies will be completed and documented along with the integrated multimedia model. In conjunction with the MIMS program, the technology will be provided to EPA and the general technical community.

Record Details:

Record Type:PROJECT

Start Date:10/01/2002

Completion Date:09/30/2004

OMB Category:Other

Record ID: 56113

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Project Information:

Progress :Two cooperative agreements studying atmospheric deposition and the fate of mercury in Vermont lakes and biota have been completed. The Regional Mercury Cycling Model (RMCM) has been tested inhouse with the Vermont mercury datasets.

The initial comprehensive sampling effort for the Cheyenne River Sioux RARE project was completed by EPA Region 8, ORD/NERL and Tribal Superfund staff. Sample collection is ongoing in support of model development to fully characterize the fate and transport of mercury and its biomagnification in these managed aquatic ecosystems of the Sioux Tribe. Preliminary data analysis has begun.

A two-part response to an Ecological Risk Assessment Support Center (ERASC) request has been initiated for a means to develop a remediation goal for mercury contamination in sediments. The first part, a description of essential data requirements, as well as additional useful data, has been submitted. The second part is currently ongoing: construction of a tool (software) that can be used to describe the process involved in deriving a remediation goal and tool.

Relevance :According to the Mercury Study Report to Congress, mercury fluxes and budgets in water, soil, and other media have increased by a factor of two to five over pre-industrial levels. The primary exposure pathway for humans and wildlife is the consumption of contaminated fish and shellfish. As mercury is a natural element, it will not degrade to simpler compounds, but rather will continue to cycle through the environment until sequestered (i.e., trapped in lake or ocean sediments). The goal of this research is to provide the scientific information and technical data needed to reduce uncertainties limiting the Agency's ability to assess and manage mercury and methylmercury risks.

Clients :Gail Mitchell and Jim Greenfield, Region 4 WTMD, 404-562-9234; Region 1; Office of Water; Dale Hoff, Region 8 OEPR, 303-312-6690; Rita Schoeny, OW, OST, 202-260-3445

Project IDs:

ID Code :15529

Project type :OMIS