The country of Denmark’s Environmental Protection Agency has conducted a literature review of current knowledge on the environmental and health risks of exposure to the most widely used nanomaterials. The Danish EPA concluded that, to date, no significant risks have been linked to the use of these substances. Seven nanomaterials were evaluated, based on their application volumes, potential human and environmental exposure, and expected persistence or bioaccumulation. Those evaluated were: Titanium dioxide; Cerium dioxide; Fullerenes; Silver; Iron; Silicon dioxide; and, Nanoclay. According to the report, nano-iron and nanoclay do not carry any health or environmental risk. Gaps in current knowledge regarding the other five substances mean further research is required before the risk potential can be fully evaluated.

http://chemicalwatch.com/8233/danish-report-on-nanomaterials-concludes-no-current-risk