Fathead minnow (Pimephales promelas Rafinesque) exposure to three novel brominated flame retardants in outdoor mesocosms: bioaccumulation and biotransformation.
The phaseout of polybrominated diphenyl ethers (PBDEs) has prompted the search for appropriate substitutes. These substitutes, referred to as novel brominated flame retardants (NBFRs), are poorly characterized in terms of their persistence, bioaccumulation, and toxicity. The authors assessed the bioaccumulation potential of 3 non-PBDE brominated flame retardants: 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), tetrabromobisphenol A bis(2,3-dibromopropylether) (TBBPA-BDBPE), and BZ-54, a mixture of bis(2-ethylhexyl)tetrabromophthalate) (BEH-TEBP) and 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EH-TBB). Replicate outdoor aquatic mesocosms were treated individually at concentrations designed to give a maximum load of 500 ng/g of flame retardant in the upper 5 cm of the sediment. Caged fathead minnows (Pimephales promelas, 24 fish per replicate) were introduced to each mesocosm and acclimated for 10 d prior to exposure. The exposure period was 42 d, followed by 28 d of depuration after transfer to a control mesocosm, during which physical, reproductive, and biochemical end points were examined. Tissue samples were taken to measure the accumulation, depuration, and biotransformation of NBFRs. Fathead minnows were observed to accumulate, after growth adjustment, BTBPE (16-4203 ng/g lipid) and TBBPA-BDBPE (>1000 ng/g lipid) but with a lack of consistent accumulation observed for EH-TBB and BEH-TEBP. However, limited biologically meaningful or consistent responses were observed in the monitored physical, reproductive, and biochemical parameters. Fathead minnows from each treatment exhibited several brominated transformation products. The authors conclude that these NBFRs have the potential to be bioaccumulative and persistent in vivo and, therefore, warrant further study of physiological effects linked to chronic, sublethal responses.
University of Guelph, Guelph, Ontario, Canada.
Benjamin P
BP
de Jourdan
Mark L
ML
Hanson
Derek C G
DC
Muir
Keith R
KR
Solomon
D000818:Animals; D001565:Benzoates / Q000737:chemistry / Q000378:metabolism; D001711:Biotransformation; D001969:Bromobenzenes / Q000737:chemistry / Q000378:metabolism; D003530:Cyprinidae / Q000254:growth & development / Q000378:metabolism*; D004781:Environmental Exposure; D004785:Environmental Pollutants / Q000737:chemistry / Q000378:metabolism*; D005411:Flame Retardants / Q000378:metabolism*; D010795:Phthalic Acids / Q000737:chemistry / Q000378:metabolism; D011075:Polybrominated Biphenyls / Q000737:chemistry / Q000378:metabolism
C576261:2-ethylhexyl 2,3,4,5-tetrabromobenzoate; D001565:Benzoates; D001969:Bromobenzenes; D004785:Environmental Pollutants; D005411:Flame Retardants; D010795:Phthalic Acids; D011075:Polybrominated Biphenyls; C081014:1,2-bis(2,4,6-tribromophenoxy)ethane; C576262:bis(2-ethylhexyl) 2,3,4,5-tetrabromophthalate; C020806:tetrabromobisphenol A
BTBPE; BZ-54; Bioaccumulation; Biotransformation; Flame retardant; TBBAPA-BDBPE