Nanotechnology holds huge potential for supplying clean water to the world's poor, but many challenges must be overcome to realise it.
When the economist Fritz Schumacher coined the phrase "small is beautiful" more than 30 years ago, he was hoping to promote "intermediate technologies" that focus on local techniques, knowledge and materials, rather than high-tech solutions to problems facing the world's poor.
But more recently, the phrase has taken on a different meaning as scientists and engineers develop nanotechnology — processes to control matter at an atomic or molecular level — and show that this field, too, can promote sustainable development.
Nowhere is the promise of nanotechnology stronger than in water treatment. Nanofiltration techniques and nanoparticles can reduce or eliminate contaminants in water and could help deliver a key Millennium Development Goal — halving the proportion of people without sustainable access to safe drinking water by the year 2015.
The challenges are many, and not just technical. Some relate to health and safety, and the need for appropriate regulations to defend both. And some are more political, for example the need to make basic technologies both accessible to and controllable by the communities that need them most. Like any new technology, community acceptance is essential if nanotechnology is to effectively work in villages across the developing world, where water problems are often the most acute.
But there are many reasons to be optimistic that we can overcome these challenges and, by doing so, that nanotechnology can pioneer a new paradigm for applying modern technology to development needs. Its current applications show how modern science and technology can be successfully blended with concern for human and environmental health on the one hand, and a commitment to community engagement in technological innovation on the other.
They also demonstrate what can be achieved when researchers — and businesses — not only work to get their products out of developed country laboratories and into local developing world settings, but also collaborate with stakeholders in the developing world itself.
Nanotech in action
This week, we publish a set of articles to explore these aspects of nanotechnology for clean water.
A background article provides an overview of the main issues, summarising the hurdles the world faces to secure clean water for its poor, and how nanotechnology can help, including an overview of key initiatives underway (see 'Nanotechnology for clean water: Facts and figures').
The development of nanosponges that soak up water and trap impurities is highlighted as an example of how nanotechnology could solve water purification problems in countries like South Africa — if testing and commercialising difficulties can be overcome (see ' Nanosponges: South Africa's high hopes for clean water').
Ashok Raichur, from the Indian Institute of Science in Bangalore, India, reminds us of the challenges ahead and argues that the key lies in engineering a useable product. But this is often easier said than done and the leap to commercial applications is still a distant goal for most developing countries (see 'Nanoscale water treatment needs innovative engineering').
Malini Balakrishnan and Nidhi Srivastava from the Energy and Resources Institute in India address the potential human and environmental dangers, arguing that while these are important, regulating nanotech for clean water should be done through existing health and safety laws, rather than new legislation (see 'Nanotech for clean water: New technology, new rules?').
Two Brazilian researchers, Paulo Sergio de Paula Herrmann Jr. and José Antônio Brum illustrate how South–South collaboration is contributing to nanotech research and development in water treatment by describing a joint programme between India, Brazil and South Africa (see 'Developing world advances nanotech for clean water').
Mohamed M. Abdel-Mottaleb, head of nanotechnology consultancy firm SabryCorp in Egypt, shows how research and business collaborations can help harness nanotechnology for clean water, arguing that nanotechnology offers both large and small developing world enterprises the chance to innovate, grow and "catch-up" with industrialised countries (see 'Nanotech for water can help business innovate and grow').
Finally, Thembela Hillie and Mbhuti Hlophe from South Africa emphasise the importance of strong partnerships between the scientists devising technological solutions and the local communities using them, highlighting some striking examples of how researchers in their country are making nanotechnology research relevant to local needs (see 'Community ownership is key to nanotech water projects').
One nano step at a time
When scientists first started promoting nanotechnology for development, various environmental groups issued sombre warnings that, unless handled carefully, the potential health and environmental risks could create the same public backlash caused by genetically engineered crops.
Fortunately, the backlash has so far failed to materialise. One reason, perhaps, is that there are no large multinational corporations to clearly identify as villains. But another is undoubtedly that critics' warnings have sensitised governments across the world to the need to give this new technology a cautious, if warm, welcome.
As the articles in this spotlight show, many challenges remain to effectively use nanotechnology to improve water supplies. But if the challenges are large, so is the gain to be made by tackling them successfully. A few years ago, the organisation that Schumacher founded, the Intermediate Technology Development Group, changed its name to Practical Action, signalling a new willingness to blend modern technology with traditional practices. In so doing, it has allowed nanotechnology, despite its origins in the research laboratories of the developed world, to sit squarely on the shoulders of "small is beautiful" campaigners.