Advances in nanotechnology tend to be geared toward the interests of industrialized countries. However, applications for tennis racquets, ski wax, and wrinkle-resistant clothing do not address the pressing needs of the more than five billion people in developing nations. Nanotechnology should be applied as a tool, in tandem with other measures, to address some of the world's most critical sustainable development problems in the areas of water, energy, health and environment, agriculture, and biodiversity and ecosystem management. These five areas, collectively known as WEHAB, were identified in the 2002 United Nations Johannesburg Summit on Sustainable Development [1].
Here, we outline four key challenges faced by developing countries and provide examples of nanotechnologies that can address these challenges. We obtained the examples from a previous study [2] in which we asked 63 experts in nanotechnology to identify and rank the ten nanotechnologies that they forecast would most likely benefit developing countries in the period 2004-2014. We also highlight recent advances in select developing countries to show that these nations are already harnessing nanotechnology to address some of their most pressing needs. This paper is based on our contribution as members of the Genomics and Nanotechnology Working Group to the UN Task Force on Science, Technology, and Innovation [3].
Reducing hunger
A substantial proportion of the population of developing countries lives in rural areas and does not have access to adequate nutritional sources. Malnutrition contributes to more than half of the deaths of children under five in less industrialized nations. Several inexpensive agricultural applications of nanotechnology have the potential to decrease malnutrition, and thus childhood mortality, by increasing soil fertility and crop productivity.
Nanoporous materials such as zeolites, which can form well-controlled stable suspensions with absorbed or adsorbed substances, could be employed for the slow release and efficient dosage of fertilizers for plants and nutrients and drugs for livestock. Nanosensors could be used to monitor crop health and, when applied to the skin of livestock or sprayed on crops, could help to detect the presence of pathogens. Moreover, nanotechnology-based methods of food packaging and storage may enable wider and more efficient distribution of food products to remote areas in less industrialized countries.
Promoting health
Nearly three million people in developing countries die of AIDS annually, tuberculosis (TB) accounts for more than a quarter of all preventable adult deaths, and in sub-Saharan Africa almost one million children die annually of malaria. Nanotechnology applications for diagnostic tools and drug and vaccine delivery are particularly promising for developing countries. Inexpensive, hand-held, multiplex diagnostic kits could be used for wide-range screening in local clinics. Researchers in India are currently developing a prototype for a nanotechnology-based tuberculosis diagnostic kit [4]. Microfluidic devices (lab-on-a-chip), biosensor arrays based on carbon nanotubes, magnetic nanoparticles, and quantum dots offer significant advantages over conventional diagnostic methods. Nanotechnology could also be used in drug-delivery systems for the slow and targeted release of drugs – characteristics valuable for countries with no adequate drug storage capabilities and distribution networks. A.N. Maitra of the University of Delhi, India currently holds several patents for nanoparticle drug-delivery systems [5]. Nanotechnology could also potentially reduce transportation costs and even required dosages by improving the shelf-life, thermostability, and resistance to changes in humidity of existing medications. In the field of regenerative medicine, researchers at China's Tsinghua University have begun clinical tests for a bone scaffold based on nanotechnology that gradually disintegrates as the patient's damaged skeletal tissue heals [6]. This application of nanotechnology is especially relevant for developing countries, where there is a high number of skeletal injuries resulting from road traffic accidents.
Improving water and sanitation
One sixth of the world's population lacks access to basic water supplies. More than one third of the population of rural areas in Africa, Asia, and Latin America has no clean water. More than two million children die each year from water-related diseases, such as diarrhea, cholera, typhoid, and schistosomiasis, which result from a lack of adequate water and sanitation. Arsenic, fluoride, and nitrates threaten water supplies in many regions. Inexpensive, easily transportable, and easily cleanable systems like nanomembranes and nanoclays purify, detoxify, and desalinate water more efficiently than conventional bacterial and viral filters. Researchers at India's Banaras Hindu University, in collaboration with US researchers, have developed a method of large-scale production of carbon nanotube filters that could be used for water remediation [7]. Nanoelectrocatalytic systems could be harnessed to decompose organic pollutants and remove salts and heavy metals from liquids, enabling the purification of heavily contaminated and salinated water for drinking and irrigation. Nanomagnetic particles and nanoporous materials such as zeolites and attapulgite can also be used to absorb toxic heavy metals, organic pollutants, and bacteria from water. Several of the contaminating substances retrieved could then be recycled easily.
Developing renewable energy sources
One third of the world's population relies primarily on traditional, nonrenewable, contaminating fuels. Nanotechnology has the potential to provide developing countries with cleaner, more affordable, and more reliable ways to harness renewable resources, averting recurrent energy crises, dependence on fossil fuels, and environmental degradation brought about by the depletion of oil and coal. Solar cells, fuel cells, and novel hydrogen storage systems based on nanostructured materials promise to deliver clean energy solutions. Quantum dots and ultrathin films of semiconducting polymers could significantly reduce the costs associated with conventional solar cells [8]. Research on the photosensitization properties of nanoporous photovoltaic devices is being conducted in Sri Lanka [9]. Electricity could also be produced cheaply by creating artificial systems that incorporate energy transduction proteins into an engineered matrix. Ideally, all of these applications would be robust and easily maintained and serviced.
What next?
Nanotechnology can play a particularly important role in addressing some of the challenges faced by less industrialized countries. Given the exponential rate of development in this field, the applications mentioned above will likely become less expensive alternatives to many conventional technologies [10]. In order for nanotechnology to progress responsibly, discussion must be balanced in two ways.
First, instead of focusing primarily on industrialized countries, attention should be paid to applications that are most relevant to the needs of developing countries, as this is where most of the world's population resides. In an earlier survey, we showed that considerable nanotechnology activity is already occurring in the developing world, with India and China, among other countries, leading the way [11].
Second, while legitimate concerns have recently been explored, the benefits for developing countries have been less clearly defined. By concentrating primarily on the potential risks that nanotechnology poses, industrialized countries threaten to derail the development of this field in low- and middle-income countries, as has been the case with genetically modified crops. This consequence can be avoided by increasing public awareness of the benefits of nanotechnology for developing countries, and by encouraging governments in the developing world, in consultation with their people, to balance the risks and benefits of nanotechnology for themselves.
Further reading
[1] Report of the World Summit on Sustainable Development. United Nations, New York, (2002)
[2] F. Salamanca-Buentello et al. PLoS Med., 2 (2005), p. e97
[3] Juma, C., and Yee-Cheong, L., Innovation: Applying Knowledge and Development, Report of the United Nations Millennium Project Task Force on Science, Technology and Innovation, Earthscan, London, (2005), 69
[4] CSIO Develops Nanotechnology for TB Diagnosis Kit, Times of India (January 3, 2004), http://timesofindia.indiatimes.com/articleshow/401636.cms
[5] Maitra et al., US Patent No. 6 579 519, (June 17, 2003); Maitra et al., US Patent No. 6 332 817, (November 27, 2001), among others
[6] Lin-Liu, J., Small Times (July 1, 2003), www.smalltimes.com/document_display.cfm?document_id=6300
[7] Savvy Sieves: Carbon nanotubes filter petroleum, polluted water, Science News (August 14, 2004), www.findarticles.com/p/articles/mi_m1200/is_7_166/ai_n6212592
[8] Hassan, M., Promoting renewable energies for sustainable rural development: Challenges, opportunities and strategies, (2004), www.jetro.go.jp/jetro/activities/high-tech/tigergate/kagi/2004/1117_Hassan.pdf
[9] P.M. Jayaweera et al. Curr. Sci., 83 (11) (2002), p. 1368
[10] Nanoscience and nanotechnologies: Opportunities and uncertainties, The Royal Society & The Royal Academy of Engineering, London (2004) www.royalsoc.ac.uk/policy
[11] Court, E., et al., Nanotechnology (2004), www.nanotechweb.org/articles/society/3/1/1/1