Chlorinated/brominated organic pollutants in aquatic birds and mammals: species- and food web-specific fate, biotransformation, trends and thyroid system effects

水禽和哺乳动物中的氯化/溴化有机污染物：物种和食物网特定的命运、生物转化、趋势和甲状腺系统影响

• 批准号: 239250-2006
• 负责人: Letcher, Robert
• 金额: $ 2.19万
• 依托单位: Carleton University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2006
• 资助国家: 加拿大
• 起止时间: 2006-01-01 至 2007-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=335146
• 关键词: Chlorinated; brominated; organic; pollutants; aquatic

There is increasing evidence that exposure to man-made environmental chemicals, particularly organic compounds that persistent and bioaccumulate in the environment, cause adverse effects in exposed wildlife and humans. Many of these environmental chemicals can be described as organohalogens as they contain the atoms chlorine, bromine or fluorine. "Legacy" organohalogen contaminants include polychlorinated biphenyls (PCBs) and numerous organochlorines pesticides. There are numerous new or "emerging" chemicals being found in the tissues of aquatic wildlife including brominated flame retardants (BFRs) such as polybrominated diphenyl ethers (PBDEs). However, there are numerous current-use BFRs unknown in the environment. All organisms possess enzymes that can mediate the metabolism, or biotransformation of foreign chemicals, which is meant facilitate their elimination from the body. Although the understanding has increased for bothh "legacy" and "emerging" organohalogens, mucb remains unknown on how biotransformation (oxidative processes and debromination) determines the fate, environmental chemistry and formation of hydroxyl- (OH-) containing metabolites at the tissue-, species, food web- and population-specific levels in aquatic wildlife. In the case of chlorinated and brominated organohalogens, formation of OH-containing metabolites can occur (e.g., OH-PCBs and OH-PBDEs) and be retained in the animal although there remains little understanding of how accumulative these metabolites are in food webs. OH-PCBs, OH-PBDEs and related compounds also possess the ability to act as hormones (e.g., thyroid), and thus affect hormone-dependent functions in an exposed animals. However, research is limited on endocrine activity of OH-containing organohalogens in wildlife species. The overall objective of the proposed research program to expand and undertake new research on the role of biotransformation on spatial/temporal dynamics and distribution, physiological fate and dynamics, and interaction of effects on the thyroid system, of organohalogens and OH-containing metabolites in model aquatic species and food webs in the Great Lakes and Arctic aquatic environments.

越来越多的证据表明，接触人造环境化学品，特别是在环境中具有持久性和生物累积性的有机化合物，会对接触的野生动物和人类造成不利影响。这些环境化学品中的许多可以被描述为有机卤素，因为它们含有氯、溴或氟原子。“遗留”有机卤素污染物包括多氯联苯和多种有机氯农药。在水生野生动物的组织中发现了许多新的或“正在出现的”化学品，包括多溴二苯醚等溴化阻燃剂。然而，环境中有许多目前使用的溴化阻燃剂是未知的。所有生物体都具有可以介导外源化学物质的代谢或生物转化的酶，这意味着促进它们从体内消除。尽管对“遗留”和“新兴”有机卤素的理解有所增加，但关于生物转化（氧化过程和脱溴）如何决定水生野生动物组织、物种、食物网和种群特定水平上含羟基（OH-）代谢物的命运、环境化学和形成，MUCB仍然是未知的。在氯化和溴化有机卤素的情况下，可能会形成含OH的代谢物（例如，尽管人们对这些代谢物在食物网中的累积程度知之甚少，但它们仍然可以在动物体内残留。OH-PCBs、OH-PBDEs和相关化合物也具有作为激素的能力（例如，甲状腺），并因此影响暴露动物的甲状腺依赖性功能。然而，研究是有限的，在野生动物物种的内分泌活性的含OH的有机卤素。拟议研究方案的总体目标是扩大和开展新的研究，探讨生物转化对五大湖和北极水生环境中模式水生物种和食物网中有机卤素和含OH代谢物的空间/时间动态和分布、生理命运和动态以及对甲状腺系统影响的相互作用。