Assessing the photocatalytic effects of metal-oxide nanoparticles on marine organisms under environmentally-relevant light regimes

评估金属氧化物纳米颗粒在环境相关光条件下对海洋生物的光催化作用

• 批准号: 1336358
• 负责人: J. Evan Ward
• 金额: $ 31.5万
• 依托单位: University of Connecticut
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-08-01 至 2017-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1336358&HistoricalAwards=false
• 关键词: Assessing; photocatalytic; effects; metal; oxide

CBET - 1336358 Titanium dioxide (TiO2) nanoparticles (NPs) are one of the most widely used manufactured nanomaterials in industrial and consumer products, with predicted environmental loads as high as 2,000,000 to 6,000,000 tons in the next 10 years. Toxicologically, engineered TiO2 NPs have been well studied with most work being performed on cell lines, bacteria, and rodents. The reported effects include inflammation, oxidative stress, and DNA damage, but are highly dependent on exposure method, and the concentration and physicochemical characteristics of the NPs. Other research has examined the photocatalytic properties of TiO2 NPs as a way of oxidizing contaminants, disinfecting drinking water, or treating tumors. These studies have reported various phototoxic effects, but typically use irradiances much higher than those found in aquatic settings. A few studies have examined the phototoxicity of TiO2 on freshwater organisms under natural light regimes, but work on near-shore marine communities is largely lacking. We argue that the phototoxicity of TiO2 NPs on shallow-water marine organisms is an overlooked area of research which is critical for a full assessment of the environmental safety of nanotechnology. Based on our extensive experience with a marine biology, metal chemistry and ocean optics, we have developed several lines of research that examine the photocatalytic effects of TiO2 under environmentally-relevant conditions. Our projects fit within the budgetary constraints of the Environmental Health and Safety of Nanotechnology program, and represent an exciting area of research in which students and PIs will work. Specifically, we will investigate: 1) incorporation of nanoscale TiO2 into naturally occurring hetero-aggregations (i.e., marine snow); 2) phototoxicity on important groups of microorganisms that live within the marine-snow complex; 3) trophic transfer efficiency via marine snow to two species of near-shore, benthic filter feeders; 4) subsequent photocatalytic effects on the physiology and cellular processes of these two animals (one translucent, one opaque).Intellectual Merit :The proposed work represents the first comprehensive study to consider common oceanographic processes (e.g., formation of marine snow) and environmentally-relevant light regimes in assessing 1) photocatalytic impacts of TiO2 NPs on microbial communities and benthic filter feeders that play key roles in marine ecosystems, and 2) trophic transfer and bioavailability to benthic organisms. Determining the potential deleterious effects of NPs on key groups of benthic organisms is not only important for comparative purposes, but also to determine how such materials might produce community level impacts. For example, toxic effects on filter feeders would compromise their capacity for benthic-pelagic coupling and, in turn, greatly impact the surrounding environment. Knowledge generated by our research will be of interest to monitoring agencies concerned with seafood safety, regulators who are developing risk-assessment protocols, scientists who study the distribution of emerging pollutants, and engineers who are designing "green" nanotechnology. As we are at the forefront of such research it is likely that our results will immediately yield important data for marine systems, and contribute to the debate regarding the potential safety of NPs in the environment.Broader Impacts :As a natural extension of our work we will train undergraduate and graduate students in concepts and techniques that cross the disciplines of biology, chemistry, and optics. Our research program will be used as a vehicle to engage educators and students in discussions about near-shore ecosystem processes, and the benefits and potential hazards of nanotechnology. Offering positive and entertaining learning opportunities for scientific discovery at an early age is crucial to capturing the enthusiasm for learning. Consequently, we will focus on developing and implementing innovative teaching materials that advocate the importance of marine environments to human health. The teaching materials will be designed in collaboration with New England Science & Sailing (NESS), a non-profit marine-science educational organization. In collaboration with NESS we will: 1) Develop lesson plans that demonstrate, in an engaging and understandable way, basic principles that drive coastal ecosystems, and explore the links between emerging pollutants and oceans and human health; 2) Train NESS senior staff to use these lessons to foster ecological literacy and draw students into science and engineering.

CBET-1336358二氧化钛纳米颗粒(NPs)是工业和消费品中应用最广泛的人造纳米材料之一，预计未来10年的环境负荷将高达200万至600万吨。毒理学方面，工程二氧化钛纳米颗粒已经得到了很好的研究，大多数工作都是在细胞系、细菌和啮齿动物身上进行的。已报道的影响包括炎症、氧化应激和DNA损伤，但高度依赖于暴露方法以及NPs的浓度和理化特性。其他研究已经检测了纳米二氧化钛的光催化性能，作为一种氧化污染物、消毒饮用水或治疗肿瘤的方法。这些研究报告了各种光毒效应，但通常使用的辐射比在水生环境中发现的要高得多。一些研究考察了自然光条件下二氧化钛对淡水生物的光毒性，但对近岸海洋生物的研究很少。我们认为，纳米二氧化钛对浅水海洋生物的光毒性是一个被忽视的研究领域，这对于全面评估纳米技术的环境安全性至关重要。基于我们在海洋生物学、金属化学和海洋光学方面的丰富经验，我们开展了几个系列的研究，以考察环境相关条件下TiO2光催化的效果。我们的项目符合纳米技术环境健康和安全计划的预算限制，代表了一个令人兴奋的研究领域，学生和PI将在其中工作。具体地说，我们将调查：1)将纳米级的二氧化钛掺入自然产生的异质聚集体(即海洋雪)；2)对生活在海洋-雪复合体中的重要微生物组的光毒性；3)通过海洋雪向两种近岸海底滤食性滤食者的营养转移效率；4)随后的光催化对这两种动物(一种半透明，一种不透明)的生理和细胞过程的影响。智力价值：拟议的工作代表了第一个综合研究，以考虑常见的海洋过程(例如，海洋雪的形成)和与环境相关的光环境，以评估1)纳米二氧化钛对在海洋生态系统中发挥关键作用的微生物群落和底栖滤食者的光催化影响，以及2)营养转移和对底栖生物的生物有效性。确定NPs对主要底栖生物群体的潜在有害影响不仅对于比较，而且对于确定这种物质可能如何产生群落一级的影响都是重要的。例如，对滤食者的有毒影响将损害其底栖-中上层耦合的能力，进而极大地影响周围环境。我们的研究所产生的知识将对关注海产品安全的监测机构、正在制定风险评估方案的监管机构、研究新兴污染物分布的科学家以及正在设计“绿色”纳米技术的工程师感兴趣。由于我们处于这类研究的前沿，我们的结果很可能立即为海洋系统提供重要数据，并有助于关于核燃料在环境中的潜在安全性的辩论。广泛影响：作为我们工作的自然延伸，我们将培训本科生和研究生跨生物、化学和光学学科的概念和技术。我们的研究计划将被用作一种工具，让教育工作者和学生参与关于近岸生态系统过程的讨论，以及纳米技术的好处和潜在危险。在早期为科学发现提供积极和有趣的学习机会对于激发学习热情至关重要。因此，我们将重点开发和实施创新的教材，倡导海洋环境对人类健康的重要性。教材将与非营利性海洋科学教育组织新英格兰科学与航海(Ness)合作设计。我们将与Ness合作：1)制定教学计划，以引人入胜和易于理解的方式展示驱动沿海生态系统的基本原则，并探索新出现的污染物与海洋和人类健康之间的联系；2)培训Ness高级工作人员利用这些课程培养生态素养，并吸引学生进入科学和工程领域。