Читать книгу Introduction to Nanoscience and Nanotechnology - Chris Binns - Страница 29

The effect on the body of exposure to nanoparticles is a hot topic in the debate on the benefits/hazards of nanotechnology, but there is limited hard information to inform the discussion. It is worth emphasizing that life on this planet evolved in a dense cloud of naturally occurring nanoparticles and we have been exposed to nanoparticles produced by human activity since the invention of fire. In addition, industrial activity based on certain types of nanoparticles, for example, carbon black, has been around since early civilizations. The difference now is that new nanotechnology industries will produce nanoparticles composed of a wide range of different materials as well as other forms of “nanomaterial” such as carbon nanotubes (see Chapter 3). Whichever way the nanoparticles enter the body, there is a highly developed immune response to clear them in the same way that any foreign invaders, including bacteria and viruses are removed. The clearance mechanisms are described in Chapter 8, Section 8.1.2, but the end result is that nanoparticles are passed out of the body via the feces or the urine. As we will see in Chapter 8, which describes medical applications of nanoparticles, keeping them in circulation for long enough to carry out their therapeutic or diagnostic function can be a problem. Here, the potential health risks of accidentally ingested nanoparticles will be discussed. There are three general surfaces in the body that act as interfaces, that is, the lungs, intestines, and skin and each will be considered.