If you search for “nano” on the internet, you will find nanotechnology is in use in almost all aspects of our daily items. It seems that once a product is stamped with “nanotech”, it becomes good and efficient. Yet what in fact is nano?
Nanometre (nm) is a unit of length, measuring (10-9m). According to the National Nanotechnology Initiative of the United States, nanotechnology refers to the application of space and substances within the scope of 1 to 100 nanometres. As the size of a nanoparticle is extremely small, its application raises the surface area to volume ratio and changes the characteristics of the substance.
Take silver as an example. It is a very stable metal in ordinary condition, and can be preserved for a long period of time. But silver nanoparticles can kill germs and are now used in manufacturing toys, clothing and medicine. Titanium dioxide (TiO2) nanoparticles, another case in point, are widely used in cosmetics and sunscreen products as they provide ultraviolet protection.
Nanotechnology also applies to environmental work. In 2007, the Polytechnic University of Hong Kong developed a kind of nanoparticle that can absorb organic and inorganic contaminants in sewage and can kill bacteria and viruses. In Washington State, United States, monitoring equipment made with nanoparticles has been developed to detect the faintest amount of radioactivity in the environment.
Nonetheless, in recent years scientists have uncovered the potential risks of nanotechnology. Studies have shown that silver nanoparticles also kill beneficial organisms in the soil and affect soil ecology. In experiments with mice, titanium dioxide nanoparticles are shown to damage DNA and are carcinogenic.
In the last two years, the U.S. Food and Drug Administration issued guidelines for the use of nanotechnology. Yet regulations on the technology and its products are still lacking internationally. Meanwhile, scientists have yet to learn more about the potential risks of the technology. At present, what consumers can do is not to put too much faith in nano-products but to buy only when needed. This can also reduce waste.
Text | Hayward Ng