Hazards Nano materials

One basis for identifying potential hazards for nano-materials is the composition of the material itself. Known hazards associated with specific material are likely to apply to the material in nano forms. However, extrapolation from studies on larger sizes to small sizes does not have data to support such interpretations. 

In addition to obtaining information to perform a hazard and dose-response evaluation, an exposure assessment will need to be conducted to estimate and characterize any potential risks associated with nanomaterials. If the hazard identification process reveals that a nanomaterial is iimocuous and does not pose a potential for eliciting any adverse human health or environmental effects, it may not be necessary to conduct additional toxicological studies or an extensive exposure assessment. In cases where the hazard evaluation determines a potential for adverse effects for the nano-material, in vitro and/or in vivo studies may be conducted to evaluate the potential for systemic exposure from inhalation, oral, or dermal penetration. Such information may help to refine the exposure assessment by providing estimates of internal doses. Much of the published human toxicological and epidemiology data relate to airborne exposme to nanoparticles or ultrafine particles. However, there are additional routes by which humans can be exposed to nanomaterials that may need to be considered, including ... 

Nano-photosynthesis can produce sugar and starch for food and further synthesis of cellulose can produce paper and wood to avoid clear-cutting forests. Carbon retrieved from the atmosphere and recycled from existing wastes by MNT will be used to make carbon nano-tubes, with superior properties to steel. Carbon will be the most common structural and functional element for a MNT-based civilization [32,33]. A carbon-based MNT material production model is conceptualized as in Fig. 9. If there is a specific need for metal, a nano-factory with trillions of nano-assemblers will synthesize steel, copper, and alloys in order to skip mining and refining [32,33]. Therefore, industrial wastewater, hazardous wastes and air pollution will all vanish. 

A.R. Khataee, V. Vatanpour, A.R. Amani, Decolorization of C.l. Acid blue 9 solution by UV/Nano-Ti02, Fenton, Electro-Fenton and Electrocoagulation processes A comparative study . Journal of Hazardous Materials, 161, 1225-1233, (2009). 

J.M. Peralta-Hernandez, J. Mann quez, Y. Meas-Vong, Francisco J. Rodriguez, T. W. Chapman, M. I. Maldonado, L. A. Godinez, Photocatalytic properties of nano-structured Ti02-carbon films obtained by means of electrophoretic deposition . Journal of Hazardous Materials, 147, 588-593, (2007). 

Another example is the wide use of nanosilver spray as a disinfectant [9]. During the short life of nanoaerosol after spraying, high-dose exposure could result in acute or chronic health effects. The mechanisms of toxicity of silver ions (Ag" ) are well known, but little is known about toxicity nano-silver induced to living organisms. In addition, limited data available has shown that other potentially hazardous and toxic materials are involved in the product and the disinfectant spray could also have negative impacts on the environment and human health. 

A.Z.M. Badruddoza, A.S.H. Tay, P.Y. Tan, K. Hidajat, M.S. Uddin, Carboxymethyl- 3-cy-clodextrin conjugated magnetic nanoparticles as nano-adsorbents for removal of copper ions synthesis and adsorption studies. Journal of Hazardous Materials 185 (2011) 1177-1186. 

PAN 11] Pant H.R., Pandeya D.R., Nam K.T. et al, Photocatalytic and antibacterial properties of a TiOa/nylon-b electrospun nano composite mat containing silver nano particles , Journal of Hazardous Materials, vol. 189, pp. 465-471,2011. 

NanocrystalUne metal oxides find excellent applications as active adsorbents for gases, the destruction of hazardous chemicals [37, 38], and catalysts for various organic transformations [39 3]. Recently, we reported the use of nano-CuO as a catalyst for C-N bond forming reactions [44]. Nano-CuO samples were obtained from NanoScale Materials, Inc., having a surface area of 136 m /g and crystalhte size of 7-9 nm. 

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