Fathead minnow (Pimephales promelas Rafinesque) exposure to three novel brominated flame retardants in outdoor mesocosms: bioaccumulation and biotransformation

Abstract

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.

Environmental Fate of Three Novel Brominated Flame Retardants in Aquatic Mesocosms

“…The present study is part of a larger research project, which included an examination of the bioavailability and toxicity of these NBFRs to aquatic organisms . The objective of the present study is to investigate the environmental fate of four NBFRs (BTBPE, TBBPA‐DBPE, BEHTBP, and EHTeBB) in outdoor mesocosms.…”

Dermal disposition of Tetrabromobisphenol A Bis(2,3-dibromopropyl) ether (TBBPA-BDBPE) using rat and human skin

“…In environmental assessments, TBBPA-BDBPE has been consistently measured in air [7], soil [8], aquatic mesocosms [9,10], and indoor dust [11][12][13], demonstrating evidence of consistent use and the likelihood of environmental persistence [7]. In the US, indoor dust was found to contain up to 0.6 nmol/g TBBPA-BDBPE, while air samples from sites around the Great Lakes reported geometric means of 0.2-1.3 fmol/m 3 [7,14].…”

Predictive Ecotoxicology and Environmental Assessment

“…Examples include nonylphenols (EU, 2003), tributyltin-based in antifouling paints (Gubbins et al, in Amiard-Triquet et al, 2013), or polybrominated diphenyl ethers used as brominated flame retardants (De Jourdan et al, 2014). Examples include nonylphenols (EU, 2003), tributyltin-based in antifouling paints (Gubbins et al, in Amiard-Triquet et al, 2013), or polybrominated diphenyl ethers used as brominated flame retardants (De Jourdan et al, 2014).…”