Chemicals Studied: This project will measure atmospheric concentrations of eight polybrominated diphenyl ether congeners (IUPAC numbers 28, 47, 99, 100, 153, 154, 183, and 209)

Geographic Areas: Samples will be taken at Houghton, Michigan and aboard research vessels on Lake Superior. Although the study will quantify the deposition of PBDEs only to Lake Superior, the methods developed during this project will be extremely relevant to other chemicals and lakes throughout the region.

Project Duration: Methodology development and testing will take place from fall of 2004 to spring of 2005. Measurements in Houghton will occur from spring of 2005 through spring of 2006. Measurements on Lake Superior will occur from spring of 2005 through fall of 2005. Data analysis and a final report will be completed by summer of 2006.

Methods Used: The project will support the construction of Multi-capillary collection devices (MCCDs) for collecting air samples at high flow rates. The MCCDs consist of a particle trap impactor, diffusion denuder, filter, and follow-up diffusion denuder through which ambient air is passed. Gaseous PBDEs collected in diffusion denuders will be thermally extracted into mini-sorbent tubes and subsequently desorbed from mini-sorbent tubes into a cooled Programmable Temperature Vaporization (PTV) inlet of a high-resolution gas chromatograph (HRGC) equipped with dual micro-electron capture detectors. Particulate-phase PBDEs will be desorbed from filters and transferred to a PTV-HRGC-mass spectrometer for analysis. Using these methods, we estimate that PBDE congener masses can be quantified in the Great Lakes region by sampling for minutes to hours rather than for days to weeks as is the case using conventional high-volume sampling or passive sampling. The short sample collection time enables micrometeorological flux measurement to be performed, which are more accurate than deposition estimation methods traditionally performed and does not require the use of unknown or uncertain parameters, such as the Henry’s law constants of PBDE congeners.

Potential Results and Implications: The novel methods being developed in the study will allow not only the first estimate of total PBDE deposition to Lake Superior, but will provide far greater accuracy than the estimates that have been made for other chemicals in the past. Accurate quantification of the flux of these chemicals into the lake is an important step toward assessing the overall impact these chemicals are having on human health and ecosystems in the region. Furthermore, the application of the methods being developed could allow more accurate and less costly quantification of deposition for PBDEs and other chemicals throughout the region.

Project Contact:
Judith Perlinger, Ph.D.
Civil and Environmental Engineering Department
Michigan Technological University
Email: jperl@mtu.edu