Bioaccumulation of Polybrominated Diphenyl Ethers and Alternative Halogenated Flame Retardants in a Vegetation–Caribou–Wolf Food Chain of the Canadian Arctic

The trophodynamics of halogenated flame retardants (HFRs) including polybrominated diphenyl ethers (PBDEs) and alternative HFRs were investigated in the terrestrial, vegetation–caribou–wolf food chain in the Bathurst Region of northern Canada. The greatest concentrations in vegetation (geometric mean of lichens, moss, grasses, willow, and mushrooms) were of the order 2,4,6-tribromophenyl allyl ether (TBP-AE) (10 ng g–1 lw) > BDE47 (5.5 ng g–1 lw) > BDE99 (3.9 ng g–1 lw) > BDE100 (0.82 ng g–1 lw) > 1,2,3,4,5-pentabromobenzene (PBBz) (0.72 ng g–1 lw). Bioconcentration among types of vegetation was consistent, though it was typically greatest in rootless vegetation (lichens, moss). Biomagnification was limited in mammals; only BDE197, BDE206–208 and ∑PBDE biomagnified to caribou from vegetation [biomagnification factors (BMFs) = 2.0–5.1]. Wolves biomagnified BDE28/33, BDE153, BDE154, BDE206, BDE207, and ∑PBDE significantly from caribou (BMFs = 2.9–17) but neither mammal biomagnified any alternative HFRs. Only concentrations of BDE28/33, BDE198, nonaBDEs, and ∑PBDE increased with trophic level, though the magnitude of biomagnification was low relative to legacy, recalcitrant organochlorine contaminants [trophic magnification factors (TMFs) = 1.3–1.8]. Despite bioaccumulation in vegetation and mammals, the contaminants investigated here exhibited limited biomagnification potential and remained at low parts per billion concentrations in wolves.