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

由于对环境和人类健康的令人担忧的影响而引起关注的化学品中，含有溴和氯的有机阻燃剂（OFR）。OFR包括大量不同种类的添加剂和反应性物质。为了减轻火灾危险，制造商将这些化学品放入从家具到纺织品的各种商业聚合物材料中。环境研究继续主要侧重于生产量大和/或在世界各地环境区划中已确定且含量很高的溴化氧自由基，例如，多溴联苯醚。研究表明，这些溴化阻燃剂会导致癌症、荷尔蒙紊乱、神经损伤和其他问题。然而，随后对多溴二苯醚应用的限制导致替代和替换臭氧化反应化学品的使用增加。有机磷酸酯FR（OPFR）是一个很好的例子，具有高产量，并且广泛用于聚合物中，可以追溯到20世纪60年代。OPFR的环境研究一般是缺席，直到最近“重新出现”与一些OPFR被报告在室内空气，灰尘，废水和污泥，虽然知识的环境生物群在世界各地仍然非常有限。环境中已确定的溴化阻燃剂（如多溴二苯醚）会降解和/或发生生物转化并代谢为其他形式，例如，高度溴化的多溴二苯醚会失去溴原子，和/或多溴二苯醚在鱼类、野生动物和人类体内转化为含羟基的多溴二苯醚。这些多溴二苯醚产品在接触过的生物体（包括人类）中具有持久性和生物累积性，并可能产生有害影响。拟议的研究将解决缺乏对新一代和替代溴化阻燃剂和有机磷阻燃剂在劳伦特五大湖的模式水生和顶级捕食者鸟类和鱼类中的降解/代谢的了解，以及对它们相对于汇聚性鱼类猎物和低等食物网的命运和生物累积的影响。五大湖盆地是数百万加拿大人生活的地方，也是顶级掠食者可能暴露在这些新一代的OFR。

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.