| This study was conducted to determine if select polybrominated diphenyl ether (PBDE) and methoxylated polybrominated diphenyl ether (MeO-PBDE) congeners existed in two inland lakes in Michigan, and if so, to evaluate the patterns of relative concentrations of congeners in the mixture. During 2006, sediment cores were collected from the deepest portions of White and Muskegon Lakes. The cores were divided into sections and subjected to analysis for carbon and organic matter content, PBDE and MeO-PBDE concentrations, and strata aging by lead-210 dating. PBDEs were detected in all strata in both lakes, while only Muskegon Lake sediments contained appreciable amounts of MeO-PBDEs. Total PBDE concentrations in both lakes were comparable, but patterns of relative concentrations of congeners were somewhat different. This was likely due to different input sources and remediation histories. The overall trend in both lakes is one of declining PBDE input. Organic matter and carbon content was correlated with PBDE concentration. It is not known why methoxylated PBDE concentrations are dissimilar between lakes, but it may be due to differences in the aquatic community present in each lake. |
