Chemicals Studied: This project is examining a large number of the contaminants monitored by the Integrated Atmospheric Deposition Network, including Great Lakes contaminants of concern such as polychlorinated biphenyls (PCBs), Polycyclic Aromatic Hydrocarbons (PAHs) and chlorinated pesticides.

Geographic Areas: The study is examining source contributions at the IADN monitoring sites at Sleeping Bear Dunes, Michigan; Sturgeon Point, New York; and Eagle Harbor, Michigan. These monitors are located on the shores of lakes Michigan, Erie and Superior, respectively.

Project Duration: Analysis of monitoring data is taking place between summer of 2004 and summer of 2005. Final results and reports will be available by fall of 2005.

Methods Used: Monitoring data from the IADN station will be analyzed in conjunction with additional with data from the Speciated Trends Network (STN) and Interagency Monitoring of Protected Visual Environments program monitors located near the IADN sites. A series of statistical analyses will be performed identify likely sources contributing to the detected contaminant concentrations and their relative contributions to the total deposition to each of the lakes studies. First, source apportionment analyses of atmospheric deposition to the Great Lakes for multiple PBTs and species of PM will be conducted. Then, characterization of sources through temporal and meteorological assessments and other statistical and data analysis activities will be carried out. Using back trajectory analysis and other supporting activities, source regions will be identified. Based on the source apportionment and characterization studies, apportionment of loadings estimates to the Great Lakes by individual sources and source regions will be estimated.

Potential Results and Implications: The expected outcome from the study is an assessment of the relative contributions of individual source types and regions to the deposition of persistent toxics to several of the Great Lakes. This information will have important implications for the ability for local, regional or national environmental management or regulatory actions to further decrease the amounts of these substances entering the lakes from the atmosphere. The study will examine only a portion of the monitoring data available from various networks around the region. If successful, the methods applied in this project could potentially be applied to numerous other chemicals and locations.

Project Contact:
Stephanie Buehler, Ph.D.
Battelle
505 King Avenue
Columbus, OH 43201-2693
Email: buehlers@battelle.org