WP20 Contaminated Harbor and River Sediment
Wednesday, 16 November 2005: 8:00 AM - 6:30 PM in Exhibit Hall

(LET-1117-816234) Polybrominated diphenyl ethers, including decabromodiphenyl ether (BDE 209), and tetrabromobisphenol-A (TBBPA) and degradation products in sediments from Lake Erie.

Chu, S.¹, Shahmiri, S.², Haffner, G.¹, Ciborowski, J.³, Hamaed, A.¹, Drouillard, K.¹, Letcher, R.^{1, 2}, ¹ University of Windsor, Great Lakes Institute for Environmental Research, Windsor, Ontario, Canada² Environment Canada, Canadian Wildlife Service, National Wildlife Research Centre, Ottawa, Ontario, Canada³ University of Windsor, Department of Biological Sciences, Windsor, Ontario, Canada

ABSTRACT- Lake Erie is the southernmost, shallowest, warmest, and most biologically productive of the five Great Lakes. High urban and industrial activities on its shores, and upstream on the Lake Huron-Detroit River-Lake Erie corridor, which means that Lake Erie is particularly vulnerable to contamination by organohalogen contaminants. Brominated flame retardants (BFRs) as contaminants in the Great Lakes ecosystem are of increasing concern. Polybrominated diphenyl ether (PBDE) congeners such as 2,2',4,4'-tetrabromoDE (BDE47) and 2,2',4,4',5-pentabromoDE (BDE99) are important environmental BFRs. The congener 2,2',3,3',4,4',5,5',6,6'-decabromoDE (BDE209) is of particular environmental concern, and is the primary component in a currently used PBDE flame retardant mixture known as decaBDE. Tetrabromobisphenol-A (4,4'-isopropylidenebis(2,6-dibromophenol)), commonly known as TBBPA, is also a major, commercially-used BFR. We presently report on the patterns, concentrations and distribution of nine major PBDE congeners, including BDE209, and TBBPA in surface sediment samples from sites spanning Lake Erie, and collected during May to June, 2004. Across Lake Erie, BDE209, BDE47 and BDE99 were the dominant congeners in sediment, where BDE47 and BDE99 comprised >70 % of the sum concentration (₈PBDE) of eight major PBDE congeners (BDE28, 47, 100, 99, 154, 153, 138, and 183). ₈PBDE concentrations varied in sediment samples from sites across Lake Erie. The ₈PBDE concentrations were generally low (0.25 - 0.5 ng/g dry weight) in the eastern and central basins. The ₈PBDE concentration in the western basin was 0.5 - > 5.0 ng/g d.w., and the highest concentration was 11.7 ng/g d.w. at a site near the western-central side of Point Pelee. Higher ₈PBDE concentrations were generally found at near shoreline sites in the western basin. In contrast to the PBDEs, TBBPA was only quantifiable at two sites, one at the mouth of the Detroit River (0.51 ng/g d.w.), and at detection levels in the mid-eastern basin. Our results indicate that PBDE contamination and deposition to sediment is highest in the western basin, and PBDEs are a more significant sediment contaminant than TBBPA, which is likely a function of water-sediment partition coefficients.

Key words: PBDEs, BDE209 and TBBPA, sediments, Lake Erie