In this study, we measured the concentrations of 65 flame retardants in water samples from five Lake Michigan tributaries. These flame retardants included organophosphate esters (OPEs), brominated flame retardants (BFRs), and Dechlorane-related compounds. A total of 59 samples, including both the particulate and the dissolved phases, were collected from the Grand, Kalamazoo, Saint Joseph, and Lower Fox rivers and from the Indiana Harbor and Ship Canal (IHSC) in 2015. OPEs were the most abundant among the targeted compounds with geometric mean concentrations ranging from 20 to 54 ng/L; OPE concentrations were comparable among the five tributaries. BFR concentrations were about 1 ng/L, and the most-abundant compounds were bis(2-ethylhexyl) tetrabromophthalate, 2-ethylhexyl 2,3,4,5-tetrabromobenzoate, and decabromodiphenyl ether. The highest BFR concentrations were measured in either the IHSC or the Saint Joseph River. The dechlorane-related compounds were detected at low concentrations (<1 pg/L). The fraction of target compounds in the particulate phase relative to the dissolved phase varied by chemical and tended to increase with their octanol-water partition coefficient. The chemical loading from all the five tributaries into Lake Michigan were <10 kg/year for the BFRs and about 500 kg/year for the OPEs.
Bibliographical noteFunding Information:
Funding for this project was provided by the U.S. Environmental Protection Agency’s Great Lakes National Program Office as part of the Great Lakes Restoration Initiative. We thank U.S. Geological Survey hydrologic technicians Brian Heissenberger, Nathan Prokopec, and David Housner for collecting and processing the water samples. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
© 2017 American Chemical Society.