Planetary Boundaries Module 9
Vivian Feng from Augsburg University, MN
On January 18th the last lecture of the Planetary Boundaries series with the topic Introduction of Novel Entities took place. The lecture was held by Vivian Feng, professor of Chemistry, and an affiliated faculty of the Environmental Studies program at Augsburg University in Minneapolis, MN. She received her B.A. degree in Chemistry from Linfield College (OR), and her PhD in Analytical Chemistry from the University of Illinois. After initiating her career as an Assistant Professor at the University of Puget Sound (WA), followed by a Research Educator position at the University of Texas, she started her current position at Augsburg University in 2008. Besides teaching analytical chemistry and general chemistry, Vivian enjoys teaching the highly interdisciplinary courses in Materials Chemistry, and Environmental Sciences. She leads an active undergraduate research lab at the interface of bioanalytical and materials chemistry. She applies analytical tools to probe the interactions at the nano-bio interface to better understand the environmental fates of novel nanomaterials. Her lab, a part of the NSF Center for Sustainable Nanotechnology, investigates the impact of nanomaterials to biological models, such as bacteria or model membranes. Introducing the abstract topic of novel entities, Prof. Feng began her lecture by showing how nanomaterials are part of various areas of our lives. The aim of her lecture was to show the two sides of novel technology, how it can help to improve environmental sustainability but at the same time may create new challenges. Pursuing that goal, she dedicated her lecture to the topics of Nano EHS (environmental health and safety research related to nanotechnology), analytical detection and characterization, monitoring transformation, assessing biological impacts and current applications to address environmental issues. As she went through those topics, she also went from molecular to bigger organisms to model systems (mesocosm model studies). As Prof. Feng explained, nanomaterial has been used in a variety of commercial products, whether we are aware or not. Some examples: Titanium oxide in food coloring, silver or copper nanoparticles in antimicrobial fabric like socks, zinc oxide in sunscreen, metal oxides in lithium-ion batteries). Nanomaterials have impacts in modern lives: agricultural uses, consumer electronics, water purification and energy storage, biomedical applications, etc. She put the topic of novel entities in perspective, explaining that we have been here before: A new product with new properties is being developed. This imposes the challenge of how to make sure that the applied test methods evaluate these new materials appropriately. There are lessons we should have already learned from introduction of new materials to the world, e.g. of some formerly new materials we know now harm either humans or fauna and flora. Nano particles are a broad category and the experimental design depends on questions, which shall be answered. In the multidisciplinary field of nano-EHS two approaches are important: the chemists’ bottom-up approach from molecular level and the top-down approach from biosphere level of engineers. There are various challenges Nano EHS research faces and aims to tackle: Detecting ENMs in biological and environmental matrices, predicting the environmental fate of nanomaterials, assessing the hazard of these materials in organisms, developing quantitative risk assessments. Prof. Feng went on to discuss the classification of toxicity-inducing nanomaterials, rounding up the topic of the scope of Nano EHS and continued with environmental transformations and biological impact before she came to discuss mesocosm model studies. She showed a case study, where a mesocosm model of wetlands etc. was built to mimic environmental reactions. As she points out, those models are important because nobody would want to dump unstudied materials in the real environment. The goal of this type of research is to look at low dose and long-term effects. In the given case study, they looked at the effects of Kocide (a copper-based nano fungicide, used in agriculture) and a gold containing nanomaterial in this mesocosm system. They learnt in their study, which was conducted over a year, that the copper oxide, being quickly soluble and mobile, was transferred to deeper aquatic sediments and existed in natural chelated forms. In the gold case, as gold doesn’t dissolve easily, which is why over time it was transferred either in the plant of the surfical sediment and reduced. Prof. Feng continued to give an overview over the state of the field. For detection of nanomaterials, an orchestra of instruments which allow in-situ measurements of in-situ conditions exists. Over the last 20 years, a deeper understanding of environmental nanomaterial transformation was developed, but as she explains, there still is a lack information on those dynamic transformation processes. Furthermore, in assessing hazard, there is also a need to focus more on molecular level changes to evaluate dosage levels which are environmentally relevant, in order to be able to fill the gap on sublethal endpoint studies. Before going into a lively discussion, Prof. Feng dedicated the last part of her presentation to some highlights of nanomaterial applications, which don’t harm but enhance environmental conditions, benefitting the environment and solving environmental issues. The three fields she gave an overlook about were food production, water treatment and energy. Looking at nano agriculture: copper oxide as fungicide was mentioned earlier as example, nano materials in agriculture are a booming field, being implemented as fertilizers, pesticides, battling diseases etc. Also, nanosensors are being developed, so that the plants can tell you, when they are ill. Modern agriculture is dependent strongly on fertilizers. The idea of some fields of nanomaterial research here is to reduce the chemical load in agriculture and consecutively in food. Nanomaterials are also beneficially and actively used in water treatment e.g. to selectively and efficiently remove unwanted components or to capture moisture in air to provide very dry areas with drinkable water or in air filters using electrospray polymer nanofibers, resulting in high airflow and efficient removal of particles PM10 and PM2.5. She went on to look at the energy sector, discussing the example of lithium ion batteries and posing the question of their after-life at the end of the life-cycle in the topic of electric car vehicles. As she laid out, currently the regeneration of some of these materials is being studied, but currently we also lack of the necessary infrastructure for regeneration. At the end of her insightful lecture, Prof. Feng recapped: Humanity in different epochs were labelled by the materials they used (e.g. stone age, iron age…), which led to the question of how do we define today’s age? Are we in a polymer or nano age? We live with and rely on novel entities and there is no way to go back to the iron age. But scientists are working on and will need to continue working on closing the loop, the life cycle of these materials, in order to lead us in a more sustainable future.