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Project Summary (300 KB PDF)

Project Title: Monte Carlo Based Multi-Media Fate Model for the Great Lakes Ecosystem

Synopsis: This project involved the development of a Monte Carlo based multi-media fate model for the Great Lakes ecosystem. This model has been implemented as an internet-based application that can be accessed by client machines throughout the region (and beyond) via the internet (see link below). Numerous important GLAD program goals can be addressed by this model. First, the environmental fate, long-range transport, and bioaccumulation potential of chemicals emitted to the ecosystem can be addressed. This will provide greater understanding of the atmospheric transport, degradation, and deposition rates for pollutants of concern. Second, the software will aid decision makers in developing rational emission reduction strategies for pollutants released to the Great Lakes. The model can be particularly beneficial for screening new chemicals for which no monitoring data exist and the physical and chemical properties of the compound are poorly understood. Finally, the model can be valuable to risk assessors when evaluating potentially hazardous levels of chemicals in the ecosystem.

Chemicals Studied: The model is designed to be used with a wide range of persistent organic compounds. Such compounds include well-known high priority chemicals such as polychlorinated biphenyls (PCBs), toxaphene, hexachlorobenzene (HCB), dichlorodiphenyltrichloroethane (DDT), as well as chemicals that have become of increasing concern in recent years, such as the polybrominated diphenyl ethers (PBDEs). Due to the Monte Carlo methods that will be used to handle uncertainty, this model is well suited for application to organic chemicals for which there is incomplete knowledge of chemical properties and environmental concentrations.

Geographic Areas: The model will be created to represent the environment of each individual Great Lakes basin. The geography and characteristics of each of the five basins (Lakes Huron, Ontario, Michigan, Erie and Superiod) have been used to parameterize many aspects of the model. The user can select which lake basin to use.

Project Duration: The project began in the Spring of 2006 and was completed in the Fall of 2007.

Methods Used: A fugacity-based multi-media model of chemical transport was created for the Great Lakes basins. Parameters with high variability or uncertainty can be treated as ranges of values rather than as single values. A Monte Carlo methods can be used to calculate model outputs and identify the range and probability of outcomes based on the ranges in model inputs. A detailed description of the methods is contained in the documentation linked below.

Potential Results and Implications: The model is an important tool to be used by resource managers, regulators and researchers to identify the fate of persistent contaminants released to the Lake Ontario environment, including air, water and soil compartments. Accessibility to the model through the internet facilitates wide use of the model by a broad range of stakeholder groups. This project will inform and support other future modeling activities.

Project Contact:
Mario J. Citra, Ph.D.
Syracuse Research Corporation, Environmental Science Center
Phone: (315)452-8406
Email: citra@syrres.com

The Model Website: http://glad.syrres.com/

Supporting Information: Model Documentation (0.6MB PDF)