Nickel nanoparticles and atherosclerosis.
This animal study is, reportedly, the first to show cardiovascular toxicity caused by inhaled nanomaterial. The New York researchers exposed mice genetically susceptible to atherosclerosis to nano-nickel hydroxide at either 0 or 79 [micro]g Ni/[m.sup.3], using a whole-body inhalation system. Instead of exposing the mice to nanoparticles 24 hours a day, the researchers mimicked a part-time human work week. Mice inhaled the nano-nickel hydroxide for five hours per day, five days per week for either one week or five months. Five months is a long time for a mouse that typically lives about three years. The researchers measured nickel content in the lung, liver, heart, spleen, and whole blood; determined presence of inflammation and oxidative damage using serum analyses, bronchoalveolar lavage fluid analyses, and assessment of mitochondrial DNA damage; and examined the ascending aorta for plaque formation and the lungs for tissue changes. In comparing the exposed mice with the controls, the researchers determined that inhaled nano-nickel hydroxide "induced significant oxidative stress and inflammation in the pulmonary and extrapulmonary organs." While aortas in mice exposed for just one week appeared unaffected compared with controls, those exposed for five months showed "progression of atherosclerosis." Also, inhaled nanoparticles accumulate in the lungs in a dose-dependent manner: "The average amounts of Ni found in the whole lung were 46.9 ng for the [one week] group and 306.7 ng for the [five month] group." The researchers did not perform this study purely for academic interest. Their study should be viewed as a preventive measure: "We believe that these findings will contribute to the further understanding of potential risks and mechanisms of NP-induced toxicity and to establishing a database for NP-specific regulations in occupational settings."
Researchers at Idaho National Laboratory have produced an inexpensive nickel-chromium alloy that converts infrared waves into electrical energy, according to a presentation at the International Nickel Study Group (April 28, 2010, Lisbon, Portugal). The material is a flexible sheet covered with thousands of microscopically small antennae able to convert infrared waves into electrical energy with 80% efficiency. Conventional solar panels convert about 20% of the sun's energy into electricity. Such technology is revolutionary and has the possibility of untold benefits. Wouldn't it be wonderful if the nanotech industry made an attempt to avoid known health risks from the beginning?
Heffernan V. Nickel in nanotechnology. Nickel Magazine. June 2000. Available at: www.nickelmagazine.org. Accessed February 22, 2011.
International Nickel Study Group. Presentation at 28 April 2010. Available at: www.insg.org/presents/Mr_Stewart_Apr10.pdf. Accessed February 22, 2011.
Kang GS, Gillespie PA, Gunnison A, Moreira AL, Tchou-Wong K-M, Chen L-C. Long-term inhalation exposure to nickel nanoparticles exacerbated atherosclerosis in a susceptible mouse model. Environ Health Perspect. 2011:119(2): doi:10.1289/ehp.1002508. Available at: http://ehp03.niehs.nih.gov/article/fetchArticle.action?articleURI=info%3Adoi%2F10.1289%2Fehp.1002508. Accessed February 12, 2011.
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|Date:||May 1, 2011|
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