Nanotechnology … EPA Faces Challenges in Regulating Risk
http://www.gao.gov/new.items/d10549.pdf
Identifies current and potential uses of nanomaterials, discusses what is known about the potential human health and environmental risks from nanomaterials, assesses actions taken by the Environmental Protection Agency to mitigate risks, and identifies other approaches taken by national authorities or U.S. states to respond to the potential risks. From the Government Accountability Office
