Brominated flame retardants in sediment cores from Lakes Michigan and Erie.

The history of polybrominated diphenyl ethers (PBDEs) and the major polybrominated biphenyl congener (BB-153) was studied in dated sediment cores taken from Lakes Michigan and Erie. The surficial concentration of total PBDE (65 [corrected] ng/g dry weight) in Lake Michigan was about 1.6 [corrected] times higher than that in Lake Erie (40 ng/g) and about 5 times higher than that [corrected] in Lake Superior (approximately 12 ng/g). The concentrations of total PBDEs in these sediments have increased rapidly, with doubling times of 5-10 years, reflecting the increasing market demand for these flame retardants over the last 30 years. BDE-209 was found to be the predominant congener in both sediment cores, making up approximately 95% [corrected] of the total PBDE load. The inventories of total PBDEs in Lakes Michigan and Erie were both [corrected] 40 ng/cm2 [corrected] The total burdens of these compounds in the sediment of Lakes Michigan and Erie were 23 [corrected] and 10 metric tons, respectively. We estimate [corrected] the total burden of these compounds in all of the Great Lakes is on the order of 100 [corrected] tons. In both lakes, BB-153 was found to increase rapidly during the 1970s and to peak around 1980.