Biotransformation of environment contaminants in biota

环境是加拿大人的头等大事。更具体地说，加拿大人担心他们体内存在化学污染物以及这些污染物对健康的影响。在我的研究计划中，我们正在研究两类主要污染物的新陈代谢、去向和毒性，即多溴联苯醚(PBDEs)和多氯联苯(PCbs)。这些化学物质是持久的，在食物链中积累，并在人类和野生动物的组织中检测到相对较高的水平。这些化学物质在人类和其他动物体内的代谢和随后消除的主要途径始于羟基化反应。这些反应发生在肝脏，并由称为细胞色素P450酶的酶家族催化。在我目前的NSERC拨款任期内所做工作的基础上，我们将使用最近开发的分析方法来测量多氯联苯和多溴二苯醚在人类和各种野生动物物种中的新陈代谢速度和程度。我们还将研究产生的羟基代谢物的毒性效应。加强对化学污染物新陈代谢的了解，对于评估可能的毒性机制和评估生物体积累或消除这些污染物的能力是重要的。这些信息将提供人类和野生动物应对污染物暴露的能力的衡量标准，并将有助于确定污染物暴露的可容忍和不可容忍水平之间的阈值。它也可能有助于预测哪些物种可能面临最大的风险。这项研究与所有加拿大人有关，尤其是那些通过饮食、工作场所或其他环境因素暴露于高水平多溴二苯醚或多氯联苯的人。

The environment is a top priority for Canadians. More specifically, Canadians are concerned about the presence of chemical contaminants in their bodies and the health effects of these contaminants. In my research program, we are studying the metabolism, fate, and toxicity of two major classes of contaminants, namely polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs). These chemicals are persistent, accumulate in food chains, and have been detected at relatively high levels in tissues from humans and wildlife. The main route for the metabolism and subsequent elimination of these chemicals in humans and other animals starts with hydroxylation reactions. The reactions occur in the liver and are catalyzed by family of enzymes called the cytochrome P450 enzymes. Building on work conducted during the tenure of my current NSERC grant, we will use recently developed assays to measure the rate and extent of metabolism of PCBs and PBDEs in humans and various wildlife species. We will also study the toxic effects of the hydroxy-metabolites produced. Increased understanding of the metabolism of chemical contaminants is important for evaluating possible mechanisms of toxicity and for assessing an organism's capacity to accumulate or eliminate these contaminants. This information will provide a measure of how well humans and wildlife are able to cope with contaminant exposure and will help define a threshold between tolerable and intolerable levels of contaminant exposure. It may also be useful in predicting which species might be most at risk. This research is relevant to all Canadians, and especially those exposed to high levels of PBDEs or PCBs via diet, workplace or other environmental factors.