Modifying factors of toxicant impacts on biota

毒物对生物群影响的改变因素

• 批准号: 8155-2012
• 负责人: Dixon, George
• 金额: $ 2.4万
• 依托单位: University of Waterloo
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=632019
• 关键词: Modifying; factors; toxicant; impacts; biota

The long-term objectives of my laboratory's program in environmental toxicology are: 1) to understand the factors (environmental and physiological) that modify the impacts of toxic chemicals on biota, 2) to develop methods to assess contaminant impacts on free-living organisms, and 3) to develop and test models predictive of the toxicity of toxicant mixtures to aquatic organisms. An understanding of modifying factors is crucial for the application of laboratory toxicology data to the field, or the application of field data collected at one site to another, during site-specific quantitative environmental risk assessment to protect the environment. While looking at the effects of various modifying factors over my career, it has become evident that what we are looking at is how environmental factors modify the bioavailability of a chemical: how exposure concentration, time and assimilation/depuration kinetics interact to achieve a critical (threshold of toxicity) chemical concentration in the organism. Models developed using this approach provide a deterministic link between hypothesis formulation and testing in environmental toxicology. We have used this approach to characterize the toxicity and bioavailability of single metals from sediments to benthic invertebrates in both the laboratory and the field, the relative contributions of dietary versus waterborne metals to toxicity in benthic invertebrates, and the acute and chronic toxicity of several waterborne metals to aquatic biota (largely through the use of the principles of the Biotic Ligand Model). In the next cycle we will look at refining and testing a model which we have developed to predict the toxicity to Hyalella azteca of up to ten metals in a mixture. In a second area of research, we will look at the interaction of selected metals and alkylated polycyclic aromatic hydrocarbons in mixture toxicity experiments with Daphnia magna. We will also assess the effect of genetic background on tolerance to metal exposure within the amphipod genus Hyalella. Overall, the work contributes to our basic understanding of the impact of environmental contaminants, and to sound scientifically-based Canadian environmental regulations.

我实验室环境毒理学项目的长期目标是：1）了解改变有毒化学品对生物群影响的因素（环境和生理），2）开发评估污染物对自由生活生物影响的方法，3）开发和测试有毒混合物对水生生物毒性的预测模型。在特定地点的定量环境风险评估过程中，了解修正因子对于将实验室毒理学数据应用于现场或将在一个地点收集的现场数据应用于另一个地点以保护环境至关重要。在我的职业生涯中，在研究各种修改因素的影响时，很明显，我们正在研究的是环境因素如何修改化学品的生物利用度：暴露浓度，时间和同化/净化动力学如何相互作用，以达到生物体中的临界（毒性阈值）化学浓度。使用这种方法开发的模型提供了一个确定性的假设制定和环境毒理学测试之间的联系。我们已经使用这种方法来表征的毒性和生物利用度的单一金属从沉积物底栖无脊椎动物在实验室和现场，饮食与水生金属的相对贡献底栖无脊椎动物的毒性，和急性和慢性毒性的几种水生金属水生生物（主要是通过使用的生物配体模型的原则）。在下一个周期中，我们将研究改进和测试我们开发的模型，以预测混合物中多达10种金属对Hyalella azteca的毒性。在第二个研究领域，我们将着眼于选定的金属和烷基化多环芳烃的混合物毒性实验与大型蚤的相互作用。我们还将评估遗传背景对片足类Hyalella属内金属暴露耐受性的影响。总体而言，这项工作有助于我们对环境污染物影响的基本理解，并有助于健全以科学为基础的加拿大环境法规。