| Abstract
| - Concentrations and congener patterns of 32 individualPBDE congeners from mono- through hexa-brominatedwere investigated in two fish species occupying similarhabitatsbut having different diets and trophic levelsand surficial sediments from several locations on the majorriver system of western North America, the ColumbiaRiver, in southeastern British Columbia, Canada. Total PBDEconcentrations have increased by up to 12-fold over theperiod from 1992 to 2000 in mountain whitefish from theColumbia River, with a doubling period of 1.6 years. Therate at which PBDE concentrations are increasing in whitefishis greater than has been previously reported worldwide.At the current rate of increase, ΣPBDE will surpass thoseof ΣPCB by 2003 to become the most prevalent organohalogen contaminant in this region. ΣPBDE in whitefish fromthe mainstem of the Columbia River range up to 72 ng/gwet weight, concentrations that are 20−50-fold higher thanin a nearby pristine watershed affected only by atmosphericcontaminant transport. Conversely, ΣPBDE in largescalesuckers were approximately an order of magnitude lowerthan in whitefish, demonstrating the influence of biomagnification and feeding habits. Congener patterns in whitefishfrom the Columbia River directly correlated with the twomajor commercial penta-BDE mixtures in use and representthe first time free-swimming aquatic biota such as fishhave been found to contain PBDE congener patterns sosimilar to commercial mixtures. PBDE concentrationsin sediments were not linked to a variety of investigatedpoint sources but were instead inversely correlated with theratio of organic carbon:organic nitrogen in surficialsediments with a pattern suggesting the dominant influenceof septic field inputs from the primarily rural population.
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