Despite some progress in understanding the environmental, health, and safety risks of nanoscale materials, the types and amounts of nanomaterials in consumer products or in development—and their possible applications and risks—remain uncertain, according to a report from the National Research Council. The report, released last week, recommends more research in four areas. One is identifying and quantifying the nanomaterials being released and who is being exposed to them. Another is understanding the processes that modify nanomaterials in ways that affect their toxicity and routes of exposure. A third is examining how nanomaterials interact with complex biological systems from subcellular components to ecosystems. The fourth is providing standardized nanomaterials, analytical methods to assess effects, and informatics tools. The report also draws attention to concerns related to the dual and potentially conflicting role of the National Nanotechnology Initiative, an interagency program that coordinates federally funded nanotechnology research and development. The initiative promotes the development of nanotechnology and the identification of its potential risks, two functions that need to be managed separately, the report states.