Friday, December 12, 2008

Nanoparticle Titanium Dioxide Hazards Identified

BrooklynDodger(s) Comment: Someday, the continuing myth that little to nothing is known about the hazards of nanoparticles or nanotechnology will be busted. ( The Dodgers(s) have previously noted that Titatanium Dioxide of all sizes is an IARC 2B carcinogen, with little controversy about nano sized. TiO2 used to be a negative control, supposedly inert and non-toxic material before it turned out to be a carcinogen. TiO2 is one of two major use nanotechnology materials, the other being carbon nanotubes.

This publication comes from a Chinese institution, a notice that development in China also includes scientific capabilities. So our colleagues from China have shown that intra nasal TiO2 gets into the brain and causes visible lesions. Nasal instillation is a valid route for hazard identification, and with some modeling could be a valid route for dose response assessment. However, for now, the warning for those who use TiO2 based skin creams, a major use, is to wash your hands before picking your nose.

Toxicology LettersVolume 183, Issues 1-3, 15 December 2008, Pages 72-80

Potential neurological lesion after nasal instillation of TiO2 nanoparticles in the anatase and rutile crystal phases

Jiangxue Wanga, b, Chunying Chena...

Laboratory for Bio-Environmental Effects of Nanomaterials and Nanosafety and Key Lab of Nuclear Analytical Techniques, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, PR China

"Nanoscale titanium dioxide (TiO2) is massively produced and widely used in living environment, which hence make the potential risk to human health. ...Central nervous system (CNS) is the potential susceptible target of inhaled nanoparticles, ...We report the accumulation and toxicity results in vivo of two crystalline phases of TiO2 nanoparticles (80 nm, rutile and 155 nm, anatase; purity >99%). The female mice were intranasally instilled with ...TiO2 nanoparticles suspension every other day for 30 days. ...The obvious morphological changes of hippocampal neurons and increased GFAP-positive astrocytes in the CA4 region were observed, which were in good agreements with higher Ti contents in the hippocampus region. Oxidative stress occurred obviously in whole brain of exposed mice ... To summarize, results provided the preliminary evidence that nasal instilled TiO2 nanoparticles could be translocated into the central nervous system and cause potential lesion of brain, and the hippocampus would be the main target within brain."

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