Halogenated flame retardants in bobcats from the midwestern United States

In response to the restrictions of polybrominated diphenyl ether (PBDE) flame retardants in various consumer products, alternative halogenated flame retardants have been subjected to increased use. Compared to aquatic ecosystems, relatively little information is available on the contamination of alternative flame retardants in terrestrial ecosystems, especially with regards to mammalian wildlife. In this study we used a top terrestrial carnivore, the bobcat (Lynx rufus), as a unique biomonitoring species for assessing flame retardant contamination in the Midwestern United States (U.S.) terrestrial ecosystems. Concentrations of ∑PBDEs (including all detectable PBDE congeners) ranged from 8.3 to 1920 ng/g lipid weight (median: 50.3 ng/g lw) in livers from 44 bobcats collected during 2013-2014 in Illinois. Among a variety of alternative flame retardants screened, Dechloranes (including anti- and syn-Dechlorane Plus and Dechlorane-602, 603, and 604), tetrabromo-o-chlorotoluene (TBCT), and hexabromocyclododecane (HBCD) were also frequently detected, with median concentrations of 28.7, 5.2, and 11.8 ng/g lw, respectively. Dechlorane analogue compositions in bobcats were different from what has been reported in other studies, suggesting species- or analogue-dependent bioaccumulation, biomagnification, or metabolism of Dechlorane chemicals in different food webs. Our findings, along with previously reported food web models, suggest Dechloranes may possess substantial bioaccumulation and biomagnification potencies in terrestrial mammalian food webs. Thus, attention should be given to these highly bioavailable flame retardants in future environmental biomonitoring and risk assessments in a post-PBDE era.

Statewide surveillance of halogenated flame retardants in fish in Illinois, USA

In order to better understand the exposure of aquatic systems to halogenated flame retardant contaminants, the present study investigated a variety of legacy and emerging flame retardants in common carp and largemouth bass collected from 58 stations across Illinois (United States). The data revealed that polybrominated diphenyl ethers (PBDEs) generally dominated the flame retardant residues in Illinois fish. Concentrations of ΣPBDEs (including all detectable PBDE congeners) ranged from 24.7 to 8270 ng/g lipid weight (median: 135 ng/g lw) in common carp and 15-3870 ng/g lw (median: 360 ng/g lw) in largemouth bass. In addition to PBDEs, Dechlorane analogues (i.e. Dec-603, Dec-604, and Chlordane Plus) were also frequently detected. Median concentrations of ΣDechloranes (including all detected Dechlorane analogues) were 34.4 and 23.3 ng/g lw in common carp and largemouth bass, respectively. Other emerging flame retardants, including tetrabromo-o-chlorotoluene (TBCT), hexabromobenzene (HBBZ), 2-ethylhexyltetrabromobenzoate (EH-TBB), and bis(2-ethylhexyl)-3,4,5,6-tetrabromo-phthalate (BEH-TEBP), were also detected in 40-78% of the fish at the monitored stations. Spatial analysis revealed significantly greater PBDE concentrations in fish living in impaired urban streams and lakes compared to those from the impaired agricultural and unimpaired agricultural/urban waters, demonstrating a significant urban influence on PBDE contamination. Future studies and environmental monitoring are recommended to focus on temporal trends of PBDEs and alternative flame retardants, as well as human exposure risks via edible fishes, in the identified Areas of Concern within Illinois.