Historical Contaminants, Flame Retardants, and Halogenated Phenolic Compounds in Peregrine Falcon (Falco peregrinus) Nestlings in the Canadian Great Lakes Basin

Concentrations and spatial patterns of persistent organic (chlorinated) pollutants (POPs), polybrominated diphenyl ether (PBDE), hexabromocyclododecane (HBCD), other flame retardants, and hydroxylated (OH) PBDE and PCB compounds were determined in nestling peregrine falcons across the Canadian Great Lakes Basin. The highest geometric mean plasma POP concentrations (ng/g ww) were sum (Σ)PCBs (35.16), ΣPBDEs (15.38), and ΣOH-PCB (8.77) with the lowest mean levels in nestlings from urban versus remote nests. PBDE congeners derived from PentaBDE and OctaBDE technical mixtures had the highest concentrations, sometimes exceeding 100 ng/g wet weight (ww); BDE-99, -153, -47, -100, and -183 comprised 92.7% of the Σ₁₄PBDE levels. BDE-209 proportions were minimal (<1%). North Shore (Lake Superior) nestlings had the highest Σ₁₄PBDE concentrations, with BDE-99, -153, and -47 dominant. Urban nestlings had higher BDE-99:BDE-153 ratios, higher BDE-183 proportions, and the only detectable HBCD concentrations, suggesting greater and more localized exposure to HBCD and PBDEs derived from OctaBDEs. Spatial patterns reflected differences in diet, local contaminant sources, and/or atmospheric deposition. Metabolism of PCBs and PBDEs likely occurred in these nestlings: OH-PCB metabolites were detected, and 4-OH-CB187 was the most abundant of these metabolites. Low ppb levels of putative OH-PBDE metabolites, dominated by 6′-OH-BDE47, were also detected in the peregrine nestlings.