It's a Small World After All
Studying the Effects of Nanotechnology on the Environment
Created in 2008, the National Science Foundation and Environmental Protection Agency (NSF-EPA) Center for Environmental Implications of Nanotechnology (CEINT, pronounced "saint") has been addressing the environmental concerns involved with nanotechnology development. CEINT is based out of Duke University, but its research is a collaborative effort that span across universities and the engineering and science disciplines. The goal of CEINT is to clarify the relationship among a broad variety of nanomaterials and the impacts of their environmental exposure, their biological effects, and their ecological consequences.
Researchers at CEINT@Carnegie Mellon—directed by Greg Lowry, professor in Civil and Environmental Engineering (CEE)—have focused on two specific areas of nanotechnology research: 1) studying the fate and transport of nanoparticles in the environment, and 2) environmental risk assessment. The research at Carnegie Mellon and other participating universities is tested in simulated ecosystem field sites at Duke.
Nanomaterial Transport, Transformation, and Fate in the Environment
Lowry leads a multidisciplinary team of experts in controlled laboratory experiments to identify and study the fundamental principles that determine nanoparticle surface chemistry, transport, and transformation. The team is comprised of Robert Tilton (ChemE), Kelvin Gregory (CEE), Jeanne VanBriesen (CEE), Neil Donahue (ChemE/Chemistry), and Alan Robinson (MechE/EPP).
The core of their research is studying the "fate" of nanoparticles in the environment, which includes factors that alter their behavior or interact with and change their surface chemistry. The transport of nanoparticles as they travel through varying environments is a related area of research because understanding both is important to assessing the potential risk of nanoparticles to the environment. CEINT's work is made more challenging because the fate and transport of different nanoparticles vary due to their diversity and complexity
Lowry's team research provides the foundation for understanding the ability of plants, animals, bacteria, and other biota to take up these nanoparticles, and the potential for those materials to bioaccumulate, cause harm, and impact ecosystems. The primary tasks in this research are to connect the chemistry and size-effects of nanoparticles to their aggregation potential and movement in the environment, and characterize biological and chemical transformations of the materials as a basis for understanding environmental persistence, transport, and bioavailability.
Today, researchers are experimenting with silver nanoparticles for their anti-bacterial properties, using them in antibiotics, disinfectants, and coating materials. Lowry's team is conducting concurrent research projects on silver nanoparticles to test their affects on and in the environment. Some of the projects are testing if these nanoparticles may pose a risk to humans and other species.
Environmental Risk Assessment of Nanomaterials
Another thrust of CEINT@Carnegie Mellon's research is addressing the environmental risk assessment of nanomaterials. Environmental risk assessments are usually performed after the environment has been harmed, but in nanomaterial research, the goal is to anticipate and prevent problems before they occur. Although researchers don't yet know what needs to be protected from which nanomaterials, they can trace contaminants through the environment to their ecological targets.
Headed by Elizabeth Casman, associate research professor in Engineering and Public Policy (EPP), the risk assessment research at CEINT fills in the blanks and incorporates the relevant properties of nanomaterials into the linked set of models that constitute an environmental risk assessment. Casman's risk assessment group tackles these problems from a number of directions, including Bayesian belief and mass balance modeling.
Under the supervision of Casman and Mitch Small, professor and associate department head for graduate affairs in EPP and professor in CEE, First year EPP Ph.D. student Jeremy Gernand is analyzing the nano-specific properties of carbon nanotubes reported in the literature to determine which properties must be tracked in a risk assessment.
An important function of CEINT's risk assessment group is to provide feedback on the Center's research program to assure that the research results will not only be usable for risk assessment. While much of this feedback is informal, first year EPP Ph.D. student Alan Masinter is taking a more theoretical approach by examining the nanomaterial research landscape for nano-silver from the perspective of which potential research areas will provide the highest value of information.
Story originally published in iNews: http://www.ices.cmu.edu/resources/iNews_Spring_10.pdf