New Generation Organic Flame Retardants and the Role of Biotransformation in Bioaccumulation in Convergent Food Webs of Top Predator Birds and Fish

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Among the chemicals that get attention for their worrisome effects on the environment and human health are organic flame retardants (OFRs) that contain bromine and chlorine. OFRs comprise a large and diverse class of additive and reactive substances. To mitigate fire hazards, manufacturers put these chemicals into commercial polymeric materials used in everything from furniture to textiles. Environmental studies continue to focus largely on brominated OFRs (BFRs) with high production volumes and/or established and substantial levels in environmental compartments worldwide, e.g., polybrominated diphenyl ethers (PBDEs). Studies have raised concerns about these BFRs in causing cancers, hormonal disruption, neurological impairment and other problems. However, the subsequent restrictions on PBDE applications have resulted in the increased use of alternative and replacement OFR chemicals. Organophosphate FRs (OPFRs) are a good example with high-production volumes, and wide use in polymers dating back to the 1960's. OPFR environmental research was generally absent until recent "re-emergence" with some OPFRs being reported in indoor air, dust, wastewater and sludge, although knowledge for environmental biota worldwide remains extremely limited. Established BFRs in the environment such as PBDEs degrade and/or are biotransformed and metabolized to other forms e.g. highly brominated PBDEs lose bromine atoms and/or PBDEs convert to OH-containing PBDEs in fish, wildlife and humans. These PBDE products can persistent and bioaccumulate in an exposed organism including humans and may elicit deleterious effects. The proposed research will address the lack of understanding of the degradation/metabolism of new generation and replacement BFRs and OPFRs in model aquatic and top predator birds and fish from the Laurentian Great Lakes, and the influence on the fate and bioaccumulation relative to their convergent fish prey and lower food webs. The Great Lakes basin is where millions of Canadians live and also as top predators are likely exposed to these new generation OFRs.