A global review of polybrominated diphenyl ether flame retardant contamination in birds

As a consequence of substantial, long-term usage, polybrominated diphenyl ethers (PBDEs) have contaminated humans, wildlife, and abiotic matrices around the world. Although several reports have reviewed PBDE contamination in general, none have focused specifically on birds. Birds have long been recognized as invaluable monitoring species for organohalogen contamination. This review summarizes most available PBDE data in birds and emphasizes several specific aspects, i.e., inter-regional differences in PBDE contamination, the extent of BDE-209 contamination, differences in congener composition patterns between piscivorous and terrestrial-feeding birds, trophic biomagnification and temporal changes in PBDE contamination. A meta-analysis of PBDE congener profiles reveals distinctly different patterns between birds utilizing terrestrial and aquatic food webs. Terrestrial-feeding birds appear to exhibit heightened Deca-BDE contamination. Inter-regional comparisons reveal elevated PBDE burdens in North American aquatic birds compared to those from the rest of the world, likely related to greater Penta-BDE demand there. Examination of North American and Chinese terrestrial birds also exhibited some of the highest BDE-209 concentrations ever reported in wildlife, and suggested that urban environments in general and some commercial activities (e.g., electronic recycling) may increase exposure of wildlife and humans to Deca-BDE. Summaries of temporal trend studies suggest that varying usage histories and regulations have influenced PBDE contamination patterns at different regions. As a consequence of continued usage of Deca-BDE around the world, significant increases in BDE-209 burdens have been observed in both North American and European birds. Examination of both wild and laboratory-exposed birds also indicated potential degradation of BDE-209 to less brominated, but more bioavailable/toxic congeners. Therefore, it would be wise to reduce releases of Deca-BDE, the only PBDE formulation remaining in production, to the environment.