Environmental fate of data poor inorganic contaminants- Developing novel tools and a better fundamental understanding

每年都有数以千计的新产品和材料被开发出来，这些产品和材料具有新颖的性能和反应性。事实上，用于制造太阳能电池、高性能磁铁、电子器件和催化剂的许多关键技术材料要么包含稀土系列元素，要么包含高活性纳米材料。尽管这些新兴产品有着众多的应用和极大的生产扩张，但关于它们对环境的潜在影响的数据却很少。这些新材料的生态风险评估的一个关键缺失因素是对它们在复杂环境介质中的浓度、形态和命运的可靠确定。 我们小组的总体研究目标是确定、更好地理解和量化控制环境系统中金属命运和生物有效性的主要生物物理化学过程。发现号拨款将用于发展严格评估纳米材料和稀土金属生态风险所需的基础科学和分析能力。资金将通过具体推进三个相关研究领域，支持我们研究的最基本方面： (1)发展我们的分析能力，以测量复杂系统中低浓度的小纳米颗粒，并区分人为和天然NP； (2)改进我们对主要物理化学过程(溶解、凝聚、异质凝聚等)的基本认识。它们决定了纳米材料在自然系统中的命运； (3)提高我们对自然系统中金属的化学形态与其生物可利用性之间关系的机械理解。 对于纳米粒子，其胶体稳定性(关于团聚)和溶解肯定会影响其生物利用度。分析学的发展将为我们提供一种新的能力，在真实和模拟的自然系统中测量最小的纳米粒子(1-20 nm)的命运。我们将通过改变重要的环境参数来对粒子的命运进行机理研究。飞行时间电感耦合质谱仪(ICPTOFMS)的即将问世将使我们能够区分工程纳米材料和天然胶体，并使我们能够更仔细地研究在接近自然条件下的异质凝聚。最后，将设计工作来逃避稀土金属络合物表观生物利用度的潜在机制，并确定比预期更大的生物量是否会导致生物效应的增加。如上所述，拟议的工作具有极其跨学科和基础性的性质，旨在通过仔细研究控制新出现的无机污染物的命运和生物可获得性的分子基础，增加我们对环境风险的总体理解。

Thousands of new products and materials, with novel properties and reactivity, are being developed each year. Indeed, many of the technology critical materials used to fabricate solar cells, high performance magnets, electronics and catalysts incorporate either the lanthanide series elements or highly reactive nanomaterials. Although these emerging products have numerous applications and a greatly expanding production, few data are available about their potential environmental impacts. One critical missing element of ecological risk assessments for these novel materials are robust determinations of their concentrations, speciation and fate in complex environmental media. The overall research objective of our group is to identify, better understand and quantify the main biophysicochemical processes that control the fate and bioavailability of metals in environmental systems. The Discovery grant will be used to develop the underpinning science and analytical capacity that is required to rigorously evaluate the ecological risk of nanomaterials and rare earth metals. Funding will support the most fundamental aspects of our research, by specifically advancing three related fields of study: (i) development of our analytical capacity to measure low concentrations of small nanoparticles in complex systems and to distinguish anthropogenic from natural NP; (ii) improvements to our fundamental understanding of the main physicochemical processes (dissolution, agglomeration, heteroagglomeration, etc.) that determine the fate of nanomaterials in natural systems; (iii) increasing our mechanistic understanding on how the chemical speciation of metals in natural systems is related to their bioavailability. For nanoparticles, their colloidal stability (with respect to agglomeration) and dissolution are certain to influence their bioavailability. Analytical developments will be pursued to provide us with a novel ability to measure the fate of the smallest nanoparticles (1-20 nm) in both real and simulated natural systems. We will perform mechanistic studies on particle fate by varying important environmental parameters. The imminent addition of a time of flight - inductively coupled mass spectrometer (ICP-TOFMS) will provide us with the capacity to distinguish engineered nanomaterials from natural colloids and allow us to more closely examine heteroagglomeration under near natural conditions. Finally, work will be designed to eludicate the mechanism underlying the apparent bioavailability of rare earth metal complexes and to determine whether or not the greater than expected biouptake leads to increased biological effects. As seen above, the proposed work is extremely interdisciplinary and fundamental in nature and is designed to increase our overall understanding of environmental risk by carefully examining the molecular basis controlling the fate and bioavailability of emerging inorganic contaminants.