Global Dialogue on Nanotechnology and the Poor ... - Nanowerk

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nanotechnology, water, & development Since the disease is dose dependent, filtration is a practical method for reducing cholera in areas where people must depend on untreated water, as no other methods are available or affordable. Therefore, a community-based study was targeted to underprivileged rural populations and sought to reduce cholera by directly involving the local community. Mothers of households were held responsible for implementation of the filtration system. The method of sari filtration was tested in a field trial. Approximately 45,000 villagers were asked to participate in the trial, in three groups of 15,000 each. A first group was asked to use the devised sari filter, a second group was provided with nylon filters (as was used to control guinea worm disease in Africa), and a third group was used as a control, who continued their routine methods of water collection and were not given either a sari or nylon filter.The nylon and sari groups were educated on how to use their respective filters, while all three groups were informed about the importance of hygiene and personal health. In addition, posters that described the process and provided pictures of plankton were shown to individuals to emphasize the critical need for removing the plankton from the water. They were advised to use filtered water for all domestic and household purposes, including drinking, washing utensils and vegetables, and bathing. An extensive questionnaire was used both prior to and after the study to assess the knowledge gained by the participants concerning hygiene and the public health value of filtration as well as the willingness to participate in this program. [2.3] Results Four months after the system was introduced to the villages, it was found that 90% of the population accepted the sari filtration system into their daily lives and were willing to protect themselves from cholera. The field trial indicated that there was a significant reduction in the cases of cholera in the groups using the nylon and sari filtration systems.The group using the sari filtration method had 48% less cholera cases than the control group (i.e., cholera was reduced by about half). It should also be noted that the rates of cholera were relatively low during the years in which the field trials were conducted, compared to historic data in the same area of Matlab, Bangladesh. ‘‘ It was clear that sari filtration contributed to bringing safer water into houses without any additional ’’ cost to the household… alternatives. It satisfied the economic, social, and environmental It was clear that sari filtration contributed to bringing safer water into houses without any additional cost to the household, resulting in significant health benefits to people who have very few other criteria indicated earlier (low cost, sociocultural acceptability, and environmental soundness), while being readily accessible to the public, especially after extreme weather conditions such as the monsoons. Although bottled water is another alternative for developing countries, it is expensive and thus will not provide a sustainable solution for the poor who suffer from waterborne diseases. ‘‘ … several viullages have started using this method to filter ’’ household water. Following the successful field trials, several villages have started using this method to filter household water. It is important that villagers are properly informed through mass communication so that more people would use the sari filtration method, mainly because it costs very little, has significant economic benefits (i.e., through improved health), and is also environmentally and socially desirable. [2.4] Simple Sustainable Development Assessment of Water Purification Methods The conventional approach to evaluate the contribution of water projects to sustainable development would be to use cost-benefit analysis, where all project effects are valued in monetary terms. However, in many cases, environmental and social effects cannot be easily valued; other techniques like multi-criteria analysis (MCA) need to be applied.This approach is also attractive to decision makers who prefer to consider a range of feasible alternatives as opposed to one “best” solution. MCA allows for the appraisal of alternatives with differing objectives and varied costs and benefits, which are often assessed in differing units of measurement. In brief, MCA examines alternative ways of meeting multiple objectives, which cannot be measured in terms of a single criterion (i.e., monetary values). As described in annex 1, the sustainable water resources management and planning (SWAMP) approach provides an integrated framework for coordination of water resource investment planning and pricing, policy analysis and formulation, as well as policy implementation and management.The framework takes into account all three aspects of sustainable development (i.e., economic, social, and environmental) and offers a tool to decisionmakers to evaluate trade-offs between various policy options. Options that lead to improvements in all three indices are referred to as “win-win” options. Once “win-win” options are realized, policymakers are able to make trade-offs among other available options. The figure within annex 1 shows how the sari-based water purification method may be assessed quite simply within the SWAMP framework using MCA.The analysis indicates a “win-win” future option with the simplified sari filtration technique, in which all 17
nanotechnology, water, & development three indices economic efficiency, social equity, and environmental protection improve. Economic losses due to sickness are reduced overall; social gains accrue to the rural poor, especially women and children; and the environment benefits from reduced pollution of water sources. [2.5] Potential for Nanotechnology-Based Purification The success of the simple sari purification method suggests that similar materials, perhaps suitably treated or impregnated with nanotechnology-based methods, could filter more effectively and thereby increase the health benefits.Villagers who used the sari method are likely to be more easily persuaded to adopt a superior filtration technology, provided it is cheap, readily available, and convenient to use. From the perspective of making development more sustainable, the health, social, and environmental benefits could be increased, but economic costs will also rise unless appropriate, low-cost nanotechnology could be developed. Some of the nanotechnology-based purification methods described in section 3 are worth considering if one wishes to go beyond the simple sari-based technique. One of the disadvantages of the conventional water treatment method is that it cannot remove dissolved salts and some soluble inorganic and organic substances. Nanomembranes and nanoclays are an inexpensive, mobile, and cleanable system that will purify, detoxify, and desalinate water. Nanosensors could detect contaminants and pathogens, thereby helping to improve health, maintain a safe food and water supply, and facilitate the use of otherwise unusable water sources. Nanoelectrocatalysts might be used for anodic decomposition of organic pollutants and the removal of salts and heavy metals from liquids, allowing the use of heavily polluted and heavily salinated water for drinking, sanitation, and irrigation.The main advantages of the membrane process are that chemicals are not added for the water treatment, relatively little energy is required, it is easy to operate and maintain, and substances can be selectively removed. The success of the simple sari purification method suggests that similar materials, perhaps suitably treated or impregnated with nanotechnologybased methods, could filter more effectively and thereby increase the ‘‘health ’’ benefits. 18
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Global Dialogue on Nanotechnology and the Poor ... - Nanowerk

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