Nanoparticles environmental issues with

Environmental and occupational health issues with nanoparticles... 

The objective of this section is to elucidate some of the current literature findings of environmental and health/safety issues with airborne nanoparticles. The Uterature review of the most recent articles in this area includes topics related to the multiple components of the risk assessment framework. This includes such important aspects as particle characteristics effecting toxicity, their fate and transport throughout the environment, the routes of exposure and the metrics by which exposure ought to be measured and the mechanisms of translocation to different parts of the body. In addition, recent studies are presented that involve the characterization of nanoparticles in the workplace during different operations and conditions. 

The particle size was below 50 nm (as determined by TEM image analysis), considerably smaller than that of the starting nanoemulsion, and showed a slight mean particle size increase and a broader size distribution with increasing O/S ratio, supporting the template effect of the nanoemulsion. The authors showed that these nanoparticles are interesting not only from a basic viewpoint but also for applications where safety and environmental concerns are important issues. 

Much emphasis has been given in the past two years to the possible toxicity of nanoparticles, by both media and scientific journals, with a general fear that they might turn up in an occupational and environmental disaster, as with asbestos, or become a serious and debated issue, like OGM. Because of their peculiar physical and chemical features, the study of nanoparticles as potential toxic agents requires a multidisciplinary approach involving disciplines from physics chemistry to biology and medicine. 

Under the Toxic Substances Control Act (TSCA), numerous nomenclature issues have arisen over the years, some of which have been discussed in this book. There will undoubtedly be new nomenclature issues to be resolved, nanoparticles being a current case in point. Issues of the past have often arisen out of administrative and sometimes arbitrary naming conventions, but risks associated with chemical substances do not depend on how they are named. Nanoparticles present different issues in the sense that the Environmental Protection Agency (EPA) stated that the TSCA regulates chemical substances of a particular molecular identity, without regard to physical properties such as size and shape. Potential for significant risk due to nanoparticles clearly exists exactly due to those physical properties. Regulators and interpreters of the TSCA must address potential risks such substances may pose even if their non-nano counterparts do not, and even if their newness does not meet the current definition of substances with different molecular identities. 

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