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: 2014
• 资助国家: 加拿大
• 起止时间: 2014-01-01 至 2015-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=544486
• 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计划的长期目标是：1）了解修改有毒化学物质对生物群的影响的因素（环境和生理），2）开发方法来评估对自由生活生物的污染物影响，以及3），以开发和测试和测试对毒性混合物的毒性对含水的有毒物质的毒性模型。对修改因素的理解对于将实验室毒理学数据应用于现场至关重要，或者在特定地点的定量环境风险评估中，将在一个地点收集到另一个地点的现场数据以保护环境至关重要。在研究各种修饰因素对我职业的影响时，我们正在考虑的是，环境因素如何修改化学物质的生物利用度：暴露浓度，时间和同化/偏移动力学如何相互作用，以达到生物体中化学浓度的关键（毒性阈值）化学浓度。使用这种方法开发的模型在环境毒理学中的假设制定与检验之间提供了确定性的联系。 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).在下一个周期中，我们将考虑精炼和测试我们已经开发出的模型，以预测混合物中最多十种金属的hyalella azteca的毒性。在第二个研究领域，我们将研究选定的金属和烷基化的多环芳烃在混合物毒性实验中与麦麦那的相互作用。我们还将评估遗传背景对摩西氏菌属内金属暴露的耐受性的影响。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，并听起来以科学为基础的加拿大环境法规。