Determination of uptake and elimination rates for isotopically enriched ZnO nanoparticles by Eisenia Fetida and the potential for trophic transfer

智力优势：工程金属纳米颗粒（NP）在洗衣机和化妆品等消费品中的应用越来越广泛。例如，ZnO NPs在尺寸小于100 nm时具有吸收紫外线（UV）的能力，并且通常存在于防晒霜中。氧化锌NPs被认为是最丰富的纳米结构家族，也被用作橡胶添加剂、颜料和光电极。环境暴露于纳米颗粒并不是一个新概念，生物体已经适应了自然暴露；令人担忧的是，最近大量涌入的人造纳米颗粒可能对环境产生有害影响。由于大多数NPs通过城市废水和污水污泥介质释放到环境中，水生和陆地系统可能是人造纳米颗粒的汇。这些纳米颗粒一旦被释放到环境中，它们的命运以及NPs转移到食物网中较高位置的生物（例如鸟类和小型哺乳动物）的可能性都是悬而未决的问题。这项研究将利用具有化学指纹的纳米颗粒来追踪土壤中NPs的命运，以及利用蚯蚓Eisenia fetida吸收和转移到更高级别生物的潜力。蚯蚓经常与土壤直接接触，是进入陆地食物网的一个重要的潜在入口，在陆地食物网中，NPs的生物积累可以在高级生物中发生。在本研究中，指纹NPs将很容易从土壤和蚯蚓中的其他锌来源中识别出来。随着时间的推移，指纹NPs在土壤系统中的行为将与其他非纳米形式的Zn（散装ZnO粉末和ZnCl2）进行比较，以评估土壤老化对不同Zn形式生物有效性的影响。这种一般方法将用于检验以下假设；1)将没有差异锌的吸收或者消除大肠fetida在所有三种形式的锌,表明锌NPs很容易被大肠fetida潜力,没有通过蚯蚓转移到陆地食物链,2)将没有差异锌的吸收或者消除大肠fetida三锌治疗后42天的老化,这些治疗方法不会不同于最初的实验。更广泛的影响：了解纳米颗粒在土壤系统中的命运及其对更广泛环境的影响，最终影响我们的生活质量，是我们社会的主要兴趣。迫切需要受过培训的科学家来理解这些类型的新兴系统。该项目将提供各级教育机会。对该项目感兴趣的少数民族学生将通过积极的NSF STEP计划“陶森STEM机会”（TOPS）进行识别和招募。在整个项目过程中，所有参与的学生都将作为一个多学科研究团队的一部分工作。这项调查的结果将由学生在陶森大学研究博览会、适当的专业会议以及同行评议的文献中传播。

Abstract#1236083Lev, StevenIntellectual Merit: The use of engineered metal nanoparticles (NP) in consumer products such as washing machines and cosmetic products is becoming widespread. As an example, ZnO NPs have the ability to absorb ultraviolet (UV) light when below the size of 100 nm, and are commonly found in sunscreens. Considered to be the richest family of nanostructures, ZnO NPs are also used as rubber additives, pigments, and in photoelectrodes. Environmental exposure to nanoparticles is not a new concept and organisms have adapted to natural exposures; the concern lies with the recent influx of manufactured nanoparticles that may have a detrimental effect on the environment. With the majority of NPs being released to the environment through municipal waste water and sewage sludge mediums, aquatic and terrestrial systems are a likely sink for manufactured nanoparticles. The fates of these nanoparticles once released into the environment and the potential for transfer of NPs to organisms higher in the food web (e.g. birds and small mammals) are open questions. This investigation will utilize nanoparticles with a chemical fingerprint to track the fate of NPs in soil and the potential for uptake and transfer to higher-level organisms using the earthworm Eisenia fetida. Earthworms are in constant direct contact with soils and are an important potential entry point into the terrestrial food web where bioaccumulation of NPs can occur in higher-level organisms. The fingerprinted NPs in this study will be readily discernibly from other sources of Zn in the soil and the earthworm. The behavior of the fingerprinted NPs in a soil system will be compared with other non-nano forms of Zn (bulk ZnO powder and ZnCl2) over time to evaluate the impact of soil ageing on the bioavailability of the different Zn forms. This general approach will be used to test the following hypotheses; 1) There will be no difference in the uptake or elimination of Zn by E. fetida among all three forms of Zn, indicating that zinc NPs are easily eliminated by E. fetida and there is no potential for transfer via earthworms to the terrestrial food web and, 2) There will be no difference in the uptake or elimination of Zn by E. fetida among the three zinc treatments after 42 days of ageing and that these treatments will not differ from the initial experiment.Broader Impacts: An understanding of nanoparticles' fate in soil systems and their impact on the wider environment, which ultimately impacts the quality of our lives, is of prime interest to our society. There is a critical need for scientists trained to understand these types of emerging systems. This project will provide educational opportunities at all levels. Minority students with an interest in working on this project will be identified and recruited through an active NSF STEP program "Towson Opportunities in STEM" (TOPS). All involved students will work as part of a multi-disciplinary research team over the course of the project. Results from this investigation will be disseminated by students at the Towson University Research Expo, at appropriate professional conferences as well as through the peer-reviewed literature.