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Wednesday, February 24, 2010

Risks of Nanotechnology

Nowadays, nanotechnology has been applied to consumer products, i.e. T-shirt with Nanosilver or Cosmetics doped with Nanoparticles. One popular question is that “Nanotechnology used has any potential risk to envelopment or to human health or not?”. Prof. Robert Schiestl from UCLA's Jonsson Comprehensive Cancer Center reported that titanium dioxide (TiO2) nanoparticles, found in everything from cosmetics and sunscreen to paint and vitamins, caused systemic genetic damage in mice. (TiO2) nanoparticles can accumulate in different organs because the body has no way to eliminate them. And because they are so small, they can go everywhere in the body, even through cells, and may interfere with sub-cellular mechanisms. In his study, mice were exposed to the TiO2 nanoparticles in their drinking water and began showing genetic damage on the fifth day. The human equivalent is about 1.6 years of exposure to the nanoparticles in a manufacturing environment.


(TiO2) nanoparticles & Pitiful rats & Carbon nanotube
(TiO2nanoparticles Figure from http://newsroom.ucla.edu/portal/ucla/nanoparticles-used-in-common-househould-112679.aspx
(Carbon nanotube Figure from www.zyvexlabs.com/EIPBNuG/EIPBN2008/2008.html)

Carbon nanotube is one of the most popular nanomaterials that are widely used in Lab or in real world applications because of its unique properties. But a great deal remains unknown about whether this material causes respiratory or other health problems. Researchers at North Carolina State University have found that carbon nanotubes can affect the outer lining of the lung in mice after a single inhalation. The findings raise concerns that inhaled carbon nanotubes may cause pleural fibrosis and/or mesothelioma. (Ref: Nature Nanotechnology 4, 747 - 751 (2009))

Nanosilver & Nemo fish and his friends
(Nanosilver Figure from http://www.slashgear.com/nano-silver-could-cause-environmental-pollution-1422792/)


The fabric with Nanosilver is able to move moisture away from the body, to enhance fabric drying, and to extinguish the growing of bacteria. A group of Swiss scientists tested how well silver nanoparticles stayed in treated fabrics under conditions similar to a washing machine. They found that most of the released particles were relatively large and that most came out of the fabrics during the first wash. The total released varied from 1.3 to 35 percent of the total nanosilver in the fabric. the released silver nanoparticles may not be toxic to people as other metals but silver can be deadly to many many fresh- and salt-water organisms – especially at their young stages of life. Many species of fish and shellfish, as well as their food, are susceptible to the metal. Widespread exposure to silver could impact some of these and disrupt ecosystem health. (Ref: Environ. Sci. Technol. 43, 8113–8118 (2009))
Up to now, no paper has not been reported for the effect of nanoparticles on human health directly. However, from many studies above, the nanoparticles can enter into human body via inhalation and these nanoparticles can become lodged in the lungs. Therefore, you must wear a face mask when you work with nano researches ( except with nano computational). And You should not use any products that can release a large amount of nanoparticles.