http://www.mondaq.com/article.asp?articleid=41892&email_access=on
Mark Hillier
"Nanotechnology is "the design, characterisation, production and application of structures, devices and systems by controlling shape and size at nanometre scale." One nanometre (nm) is one billionth of a metre. B y controlling matter at such a scale, materials with new properties and uses can be created. Few papers have been published on the effects of nanoparticles on the health of animals and none on the effects on humans, but concerns have been raised that the likely increased reactivity of nanoparticles and their ability to cross cell membranes (pass through the outer surface of the cell) may have adverse environmental and health effects. For instance, creams applied to the skin containing nanoparticles of sufficiently small size may allow the nanoparticles to pass though the outer layer of the skin, either through pores in the skin or through the surface of skin cells directly. The potential ability of nanoparticles to pass through the outer surface of cells also has implications for air-borne nanoparticles which may be inhaled and pass through the cells of the lung." [Science]
