Biotransformation of commercial chemicals in food-webs

这一研究方案的目的是提高对商业化学品的环境命运和影响的认识，并开发更好的方法来测量和评估化学品接触以及对野生动物和人类的风险，以支持保护人类和环境健康的国家和国际倡议。以前的研究涉及物理化学因素在水生和陆生食物网中控制化学物质生物积累的作用。本研究旨在探讨生物转化对食物网生物积累的作用。缺乏测量生物转化速率的方法，以及随后缺乏大多数商业物质的生物转化数据，现已被确定为正在进行的评估化学品在环境中的命运和影响的关键科学知识差距。该研究的目标是：(i)开发确定体外和体内研究中化学物质生物转化速率的方法；（ii）调查体外和体内研究以及现场测量的生物转化速率之间的关系；（iii）开发和测试可用于监管目的的代谢物质的数学生物积累模型。这项研究包括4个项目，涉及一组常见的化学物质。项目1包括开发一种新型体外给药系统，以测量极疏水物质在肝脏和肠道匀浆中的体外生物转化率。项目2开发和应用测量大鼠和虹鳟鱼体内生物转化率的方法。项目3涉及开发一个药代动力学模型，用于研究体内和体外生物转化速率。项目4开发并测试了经过生物转化的物质的食物链生物积累模型。这项研究对以下方面产生了益处：(i)野生动物和人类健康（通过识别有害物质），（ii）化学品制造商（通过改进管制性化学品评价议定书），（iii）环境咨询业（通过建立生物转化试验议定书的专门知识），以及（iv）支持加拿大政府开展国家和国际化学品管理倡议。

This research program aims to enhance knowledge of the environmental fate and effects of commercial chemicals and to develop better methods for measuring & assessing chemical exposure and risks to wildlife & humans in support of national and international initiatives to protect human and environmental health. Previous research involved the role of physical-chemical factors controlling the bioaccumulation of chemicals in aquatic and terrestrial food-webs. The proposed research investigates the role of biotransformation on bioaccumulation in food-webs. The lack of methods to measure biotransformation rates and the subsequent lack of biotransformation data for most commercial substances have now been identified as a key scientific knowledge gap in the on-going evaluation of the fate and effects of chemicals in the environment. The goal of the research is (i) to develop methods for determining the rate of biotransformation of chemicals in in-vitro and in-vivo studies and (ii) to investigate the relationship between biotransformation rates measured in in-vitro and in-vivo studies and in the field and (iii) to develop and test mathematical bioaccumulation models for metabolizing substances that can be used for regulatory purposes. The research includes 4 projects involving a common set of chemical substances. Project 1 includes the development of a novel in-vitro dosing system to measure in-vitro biotransformation rates of extremely hydrophobic substances in liver and intestinal homogenates. Project 2 develops and applies methods for measuring in-vivo biotransformation rates in rats and rainbow trout. Project 3 involves the development of a pharmacokinetic model for relating in-vitro and in-vivo biotransformation rates. Project 4 develops and tests a food-chain bioaccumulation model for substances that undergo biotransformation. This research produces benefits to (i) wildlife and human health (by identifying harmful substances), (ii) chemical manufacturers (by improving regulatory chemical evaluation protocols), (iii) environmental consulting industry (by establishing know-how on biotransformation test protocols, and (iv) supports the Canadian government in their national and international initiatives of chemical stewardship.