I came across the following video slideshow by Andrew Maynard (2020science.org), a researcher in nanotechnology. It’s a nice, gentle introduction to nanoparticles and their properties.
The key points he makes about these new materials are
* the particles are small
* they are “strange” – they don’t behave how you might expect and the properties of a substance manufactured or created as a nanoparticle can be different from the same substance in the form of larger particles
* they are “sophisticated” – in that they can be used to manufacture complex products with advanced uses
There are inevitable concerns about the toxicity of nanoparticles and the risks from exposure, both from an occupational and environmental context.
* the small size of the particles means that they can, potentially, be absorbed easily into the body by inhalation AND skin contact (there is evidence that some particles can be absorbed through intact skin)
* nanoparticles are much more likely to be absorbed into the blood via the lungs than their larger cousins. Once absorbed they can make their to other organs where they may be able to exert toxic effects.
* their small size also means that they can be potentially absorbed into cells where larger particles of the same substance would not
* the “strangeness” of nanoparticles means that it can be difficult to predict what their toxicological properties will be, even where there is a good understanding of the toxicity of larger particles of the same substance
* In some cases, effects such as cancer are due to the physical form of particles and their Small size (aka asbestos fibres) rather than their chemical nature
It is too early to now whether any of these concerns will be borne out in practice. However, it’s an area where a lot of research is taking place.