Polybrominated diphenyl ethers and hydroxylated and methoxylated brominated and chlorinated analogues in the plasma of fish from the Detroit River

Novel classes and congeners of contaminant residues that are structurally analogous to polybrominated diphenyl ether (PBDE) flame retardants were assessed in the plasma of seven benthic- and six pelagic-feeding fish species from the highly contaminated Detroit River corridor, namely, hydroxylated-PBDEs (OH-PBDEs), methoxylated-PBDEs (MeO-PBDEs), and the antimicrobial OH-trichlorodiphenyl ether, triclosan, and its methylated (MeO) triclosan analogue. In all samples Sigma PBDE concentrations were comprised mainly of BDE47, BDE99, and BDE100 (> 85%) and ranged from 155 pg/g wet weight (ww) to 21 069 pg/g ww. Of the 14 OH-PBDE congeners assessed, as many as 10 congeners were identified, although profiles were generally dominated by 6-OH-BDE47 with lesser amounts of 2'-OH-BDE68, 4'-OH-BDE49, and 4-OH-BDE42. 2:OH-PBDE concentrations ranged from 2.7 to 198 pg/g ww, with Sigma PBDE to Sigma OH-PBDE concentration ratios ranging from 0.0005 to 0.02. OH-PBDEs are likely derived in these freshwater species as metabolites of precursor PBDEs and are subsequently retained in the blood, for example, 6-OHBDE47, 4'-OH-BDE49, and 4-OH-BDE42 could be derived from BDE47. Portions of concentrations of the OH-PBDEs may also be of alternate origins and are accumulated and retained in these fish. In all samples, the 14 MeO-PBDEs monitored were below detection (< 0.01 pg/g ww). Anthropogenic triclosan concentrations ranged from 750 to > 10 000 pg/g ww and is clearly a bioaccumulative halogenated phenolic compound in these fish. MeO-triclosan concentrations were considerably lower. In addition to emerging classes of brominated contaminant such as PBDEs,whether of metabolic or anthropogenic origin, fish collected from the Detroit River are exposed to a complex profile of PBDE-like organohalogens.