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July 2006 Symposium on Nanotechnology and the Environment: Life Cycle of Nanomaterials: Highlights, Question and Answer Session Session
July 12, 10:30-11:30 AM
Dr. Stig Irving Olsen, NANO DTU, Technical University of Denmark, Department of Manufacturing Engineering Management, Lyngby, Denmark
Highlights Nanotechnologies imply a vast array of benefits to society many of which may also be environmentally beneficial, e.g. reductions in energy use and improved functionality of material. But apart from the potential toxicological risks of nanoparticles nanotechnology may also imply an increased use of scarce resources, a high energy demand and waste in production, problems in recycling etc. To ensure a sustainable development of nanotechnologies it is important to adequately meet human demand and to assess the entire system.
Life cycle assessment (LCA) is a useful tool for this but a simplified approach may be needed. LCA is an environmental assessment tool that focuses on the services provided to society, very often the functionalities provided by a product. LCA has a holistic perspective since the entire life cycle of a product from the extraction of raw materials to the final disposal is included and because all relevant environmental impacts and consumption of resources are assessed. It can be used for the identification of problematic impacts in the life cycle and for comparisons between products and/or life cycle stages. International Organization for Standardization (ISO) standards are developed for LCA.
In nanotechnology manufacturing, the use of scarce metals and materials may increase; since only small amounts are needed, cost is not so prohibitive. This creates increased impact upstream. For example, it is 2000 times more energy-intensive to extract gold from ore than steel. Also, the use of Sc (scandium)doped fullerenes in automobile fuel cells could quickly deplete Sc, a rare material. Experiences from electronics show that disassembly and recycling of scarce materials is very difficult.
Maintaining a clean nanotechnology production environment to ensure pure products requires lots of high-energy input both in the process and upstream.
Using three real cases of fullerenes application some environmental aspects of the life cycle were illustrated, e.g. the need to purify nanoparticles in organic solvent prior to use in composite and low yield as well as the potential release during incineration of nanotubes in composites.
Both the induced impact of nanotechnology function as well as the impact of whatever the new technology is replacing needs to be assessed. Forecasting methods are needed in environmental assessment. It is important to interpret risks during the life cycle. And finally the need to make environmental concerns inherent to nanoresearch was emphasized.
Question-and-Answer Session When asked whether benefits of nanotechnology outweigh risks, Dr. Olsen indicated that there are many applications for which it will be difficult to weigh benefits versus risks. For example, environmental impact assessments are typically not performed for medical applications. When asked about the importance of recycling of nanomaterials, Dr. Olsen indicated that recycling will be critical to realizing energy savings, especially for products/processes that use scarce resources. A commenter noted that the Woodrow Wilson Center and the European Commission (EC) will hold a workshop on LCA and nanotechnology.