Great Lakes Open Lakes Trend Monitoring Program: Polybrominated Diphenyl Ethers (PBDEs)
Log-linear regression of PBDE concentrations in Lake Trout and Walleye (U.S. EPA; Lake Erie), show significant declining trends of 5.8%/year for tetra-BDEs, 6.4% for penta-BDEs, and 3.4% for hexa-BDEs in Lake Ontario and annual declines of 19% for tetra-BDEs and 17% for penta-BDEs from Lake Michigan. PBDE concentrations in Lakes Superior, Huron, and Erie also appear to be declining as the slopes of the regressions are all negative; however, the slopes are not significantly different from zero
at a = 0.05 with a power of 80%. The majority of tetra-BDE and all hexa-BDE concentrations reported for Lake Trout and Walleye in 2009 from all the Great Lakes are below Environment Canada's Federal Environmental Quality Guidelines; however, all measured penta-BDE concentrations are well above the FEQG of 1.0 ng/g ww.