Polybrominated diphenyl ethers in sediment and caged mussels (Elliptio complanata) deployed in the Niagara River

Polybrominated diphenyl ethers (PBDEs) were detected in caged mussels (Elliptio complanata), deployed in the Niagara River for 3weeks in 2003, 2004 and 2006 and in sediment collected from the river and tributaries. The highest concentrations (measured as the sum of 17 BDE congeners) were in mussels deployed within tributaries to the American side of the River (Cayuga Creek: 11.5ngg(-1) wet wt.; Two Mile Creek 9.5ngg(-1); and Gill Creek: 5.8ngg(-1)). In addition to contributions from the atmosphere, each urban tributary has multiple potential sources of PBDEs which include storm sewers, sewage treatment plants and industries located upstream of the sampling sites. Total PBDE concentrations in sediment ranged from 0.25 to 188ngg(-1). In general, mean mussel tissue concentrations were positively correlated with sediment BDE concentrations. Total PBDE concentrations were higher in mussels deployed at most sites in the Tonawanda Channel which is highly industrialised, compared with mussels deployed on the Canadian side of the upper Niagara River where the surrounding area is generally rural. The sum of BDE-47, -99, -100, -153, -154 and -209 contributed between 92% and 96% of the total BDE concentrations in all of the mussel samples. BDE-209 represented between 39% and 100% of the total BDE in sediment samples. BSAFs in mussels ranged from 1 to 18 depending on the sampling station. Ratios of BDE-47/99 and BDE-100/99 and congener patterns in mussels and sediment were suggestive of the penta formulation as the historical source.