Incidental nanoparticles

Most nanoparticle uptake and translocation research has quantified nanoparticles in vivo using some type of unique particle label. For example, nanoparticle laboratory studies have included radioactive particles [4], trace metals such as gold and iridium [7], and fluorescent particles [8]. However, the population exposures most relevant to health involve the emissions or deliberate release of high-production-volume manufactured nanomaterials and exposures to incidental nanoparticles, such as soot. Combustion emissions and manufactured powders such as fumed silica, ultraflne titanium dioxide (Ti02), and similar industrial materials rarely have a unique and easily detected label. 

Incidental nanoparticles are produced as a side product of anthropogenic processes such as in automobile exhausts. One interesting but unexpected source of incidental nanoparticles relates to the discovery that silver and copper metallic nanoparticles are formed spontaneously on the surface of manmade objects (made of Ag and Cu) that humans have long been in contact with and that macroscale objects represent a potential source of nanoparticles in the environment. 

Iron oxide nanoparticles are undoubtedly one of the most investigated nanoparticles owing to their importance in industrial and medical appUcations. Hematite nanoparticles are comparatively more stable and therefore have wider applications as well. While several methods are available for the synthesis of nanoparticles, the green synthesis routes are preferred, more so iu biological apphcations. It has beeu demoustrated that natural products such as polysaccharides can be employed as effective templates, both through sacrillcial and otherwise routes to generate mono-dispersed nanoparticles of below 20 run. Such methods are easy to adopt for other ferrite nauoparticles as well. Incidentally, some of the polysaccharide methods are facile and possibly simple for rephcation at industrial scales. 

These NSPs can further be distinguished in three types as natural, incidental, and engineered nanoparticles depending on their pathway. Natural nanoparticles, which are formed through natural... 

It should be understood that the types of toxic effects discussed above are limited to situations where nanoparticles ctfe inhcded or placed in the trachea as insoluble particles. The form of nanoparticles in applications are either dissolved in solution (e.g., through injection for medical uses) or inside components (e.g., computers) and are likely not available for exposure in these ways. We expect that the risk of toxic effects is significantly reduced in these types of products. However, incidental inhalation exposure by workers in the industry represents a potential health issue that requires more research. This is well understood by the U.S. National Institute of Occupational Safety and Health (NIOSH). They recommend limiting exposure to workers until more knowledge is gained, and have identified ten key research topics, including ... 

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