Proponents of nanotechnology say it has many applications that could benefit society, while opponents say it could pose serious risks to people and the environment.
Nanotechnology is a broad term that refers to the design and creation of tiny products, which have proven both promising and controversial.
The term “nano” refers to the fact that these products are 100 nanometres in size or smaller – a thousand times thinner than a human hair. At this scale, materials can behave very differently to when they are in bulk form, and this can give them new and potential useful properties.
For example, nanomaterials may have a different melting point, or ability to conduct electricity. Such these differences make them potentially very useful for creating products that are lighter, stronger, cleaner, less expensive and more precise than conventional ones.
Carbon nanotubes, for instance, are tubes made of a sheet of carbon that is only a single atom thick. At this scale the carbon is stronger than steel but many times lighter.
These nanotubes could one day be used as a cheap but effective material for making cars and planes.
Many products that have been made through nanotechnology are already on sale. They include sunscreen creams that contain nano-scale zinc oxide or titanium oxide, whose tiny size makes the sunscreen less visible when people apply it on their skin.
Other nano-products that already exist include self-cleaning glass, water-resistant clothing and scratch-proof materials. Nanotechnology is also used in foods, packaging and pesticides, among other things.
Some people think nanotechnology could lead to miniaturisation of manufacturing to the molecular level that mimics the way enzymes inside human cells break and rearrange the bonds that hold molecules together.
The vision is of potentially self-replicating ‘assemblers’ – tiny devices that work in unison like miniature versions of factory assembling lines – to produce ‘nanomaterials’. But these degree of complexity is many years away.
Opponents of nanotechnology point out that there has been very little research into its safety, and indeed some evidence of risks to human health and the environment.
There are concerns too that materials that are safe in bulk form could pose threats when in a nano-scale, either because of their small size of because they exhibit different properties.
Experiments on animals such as mice have linked nano-particles to health problems similar to those caused by exposure to asbestos.
There is also very little regulation of how the technology is used and little testing of products before they reach the market. This means that consumers rarely know if a product contains nano-particles and countries have little power to decide whether or not such products can be exported to them.
ALTERNATIVES / SOLUTIONS
Risks – both perceived and real – have prompted governments to begin to consider whether they need to regulate the development and use of nanotechnology.
The United Kingdom’s science academy, the Royal Society, recently made a series of recommendations in response to emerging evidence of serious nanotoxicity risks.
It said nanoparticles should be subject to new safety assessments prior to their inclusion in consumer products, that factories and research laboratories should treat nanoparticles with the presumption that they are hazardous, and that the release of nanoparticles into the environment should be avoided as far as possible.
Nongovernmental, scientific and industry organisations that work on nanotechnology are good sources of news, information and interviews.
They include the International POPs Elimination Network, the Foresight Institute (which aims to promote benefits and avoid risks of nanotechnology), the ETC Group (which urges much greater consideration of the safety of nanotechnology) and Practical Action (which focuses on potential uses of nanotechnology in the water, energy and agriculture sectors in developing nations).
Another good source of news, opinions and story ideas with a focus on developing nations is SciDev.Net’s nanotechnology collection.
As with other subjects, journalists who report on nanotechnology should take special care when communicating risk.
CASE STUDY – Nanotechnology for clean water
Nanotechnology could one day be used to make water safe for millions of people who currently drink untreated water.
Already, products that use nanotechnology are on the market. They include porous membranes that act as filters, trapping any organisms and particles that are bigger than their pores and allowing water to pass freely.
Other products are being developed to attract and bind highly toxic chemicals such as arsenic or actually break pollutants down into safe compounds, rather than trapping them.
Researchers are also using nanotechnology to develop fast and effective sensors that can detect contaminants in water. Others are developing nanotechnologies that can be applied to fabrics to enable them to absorb water – which would enable rural communities in arid areas to harvest water for future use.
Proponent so nanotechnology said it would lower costs, environmental impacts, energy needs and make a more effective, longer lasting solutions than anything possible before.
Others caution that the unique properties of nanomaterials may make them toxic so safety must be assured, and that technical solutions will be irrelevant unless they can be adapted to local needs and conditions.
AzoNano – What is Nanotechnology and What Can It Do?
How Stuff Works – Nanotechnology
IPEN briefing paper on nanotechnology [PDF]
SciDev.Net – nanotechnology for clean water – facts and figures