Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.
Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.
OCR for page 1
Global Issues in Water, Sanitation, and Health: Workshop Summary Workshop Overview GLOBAL ISSUES IN WATER, SANITATION, AND HEALTH Water is a fixed commodity. At any time in history, the planet contains about 332 million cubic miles of it. Most is salty. Only 2 percent is freshwater and two-thirds of that is unavailable for human use, locked in snow, ice, and permafrost. We are using the same water that the dinosaurs drank, and this same water has to make ice creams in Pasadena and the morning frost in Paris. It is limited, and it is being wasted. … But usage is only part of the problem. We are wasting our water mostly by putting waste into it. Rose George (2008) Worldwide, over one billion people lack access to an adequate water supply; more than twice as many lack basic sanitation (WHO/UNICEF, 2006). Unsafe water, inadequate sanitation, and insufficient hygiene account for an estimated 9.1 percent of the global burden of disease and 6.3 percent of all deaths, according to the World Health Organization (Prüss-Üstün et al., 2008). This burden is disproportionately borne by children in developing countries, with water-related factors causing more than 20 percent of deaths of people under age 14. Nearly half of all people in developing countries have infections or diseases associated with inadequate water supply and sanitation (Bartram et al., 2005). The effects of water shortages and water pollution have been felt in both industrialized and developing countries, and it will be necessary to transcend
OCR for page 2
Global Issues in Water, Sanitation, and Health: Workshop Summary international and political boundaries to meet the world’s water needs in a sustainable manner that will conserve and preserve this common resource. In the last few decades, national and international organizations from both the public and private sectors have come together to tackle global issues in water and sanitation. The lack of access to and availability of clean water and sanitation has had devastating effects on many aspects of daily life. Areas without adequate supplies of freshwater and basic sanitation carry the highest burdens of disease which disproportionately impact children under five years of age. Lack of these basic necessities also influences the work burden, safety, education, and equity of women. While poverty has been a major barrier to gaining access to clean drinking water and sanitation in many parts of the developing world, access to and the availability of clean water is a prerequisite to the sustainable growth and development of communities around the world. As the human population grows—tripling in the past century while, simultaneously, quadrupling its demand for water—Earth’s finite freshwater supplies are increasingly strained, and also increasingly contaminated by domestic, agricultural, and industrial wastes (UNESCO, 2006). Today, approximately one-third of the world’s population lives in areas with scarce water resources (UN, 2009). Nearly one billion people currently lack access to an adequate water supply, and more than twice as many lack access to basic sanitation services (Prüss-Üstün et al., 2008). It is projected that by 2025 water scarcity will affect nearly two-thirds of all people on the planet (Figure WO-1). The majority of these people live in rural areas without community infrastructure. With the rise of “megacities,” urban population growth may overtake the ability of local communities and governments to meet their residents’ water needs through infrastructure creation and improvements, adding to the estimated 3.6 million people who die each year from inadequate access to safe water, sanitation, and hygiene (Prüss-Üstün et al., 2008). Nearly one in four deaths among children under the age of 14 result from inadequate access to safe water, sanitation, and hygiene. Lack of these necessities also establishes a vicious cycle, for poverty bars many in the developing world from obtaining the safe drinking water and sanitation needed to drive sustainable community growth and development. Recognizing that water availability, water quality, and sanitation are fundamental issues underlying infectious disease emergence, the Forum on Microbial Threats of the Institute of Medicine held a two-day public workshop in Washington, DC, on September 23 and 24, 2008. Through invited presentations and discussions, participants explored global and local connections between water, sanitation, and health; the spectrum of water-related disease transmission processes as they inform intervention design; lessons learned from water-related disease outbreaks; vulnerabilities in water and sanitation infrastructure in both industrialized and developing countries; and opportunities to improve water
OCR for page 3
Global Issues in Water, Sanitation, and Health: Workshop Summary FIGURE WO-1 Population growth, climate change, reckless irrigation, and chronic waste are placing the world’s water supplies in danger. SOURCE: Reprinted from Mittelstaedt (2009) with permission from The Globe and Mail; based on UN (2009). and sanitation infrastructure so as to reduce the risk of water-related infectious disease.1 Some topics important to water quality and health were either not covered at the workshop, covered only in passing, or were explored in greater detail in other National Research Council (NRC) reports. These topics included desalination,2 bioterrorism,3 conflicts over water and the implications for global security,4 1 For a discussion about Bradley’s four categories of water-related disease (water-borne, water-washed, water-based, and water-related insect vectors), see page 18 and his paper in Chapter 1. 2 See NRC (2004a,b,c, 2005, 2006, 2007, 2008a,b). 3 See NRC (2002). 4 See Running Dry DVD (enclosed) and MacPherson in IOM (2008).
OCR for page 4
Global Issues in Water, Sanitation, and Health: Workshop Summary pharmaceuticals,5 heavy metals,6 and issues related to runoff from farms and pollution of water supplies.7 Organization of the Workshop Summary This workshop summary was prepared for the Forum membership by the rapporteurs and includes a collection of individually authored papers and commentary.8 Sections of the workshop summary not specifically attributed to an individual reflect the views of the rapporteurs and not those of the Forum on Microbial Threats, its sponsors, or the Institute of Medicine (IOM). The contents of the unattributed sections are based on the presentations and discussions at the workshop. The workshop summary is organized into chapters as a topic-by-topic description of the presentations and discussions that took place at the workshop. Its purpose is to present lessons from relevant experience, to delineate a range of pivotal issues and their respective problems, and to offer potential responses as discussed and described by the workshop participants. Although this workshop summary provides an account of the individual presentations, it also reflects an important feature of the Forum’s philosophy. The workshop promotes a dialogue among representatives from different sectors and allows them to present their beliefs about which areas may merit further attention. The reader should be aware, however, that the material presented herein expresses the views and opinions of the individuals participating in the workshop and not the deliberations and conclusions of a formally constituted IOM consensus study committee. These proceedings merely summarize the statements of participants at the workshop and are not intended to be an exhaustive exploration of the subject matter nor a representation of a consensus evaluation. Global and Grassroots Perspectives The workshop opened with a screening of the film Running Dry (Thebaut, 2005; CD included on the inside front cover of report volume), introduced and followed by remarks from its writer, producer, and director, James Thebaut. The documentary explores the growing global water crisis and its staggering toll of some 14,000 “quiet preventable deaths” per day. Focusing on China, the Middle East, Africa, India, and the United States, Running Dry presents compelling argu- 5 See Davies in IOM (2009). 6 See NRC (1993a, 2008c). 7 See NRC (1993b); see also Caravati et al. in Chapter 4. 8 Speakers Mark Sobsey, Thomas Clasen, and Vahid Alavian did not submit manuscripts for this summary report. To ensure that their contributions to this meeting were captured in this summary report we have supplemented the overview section of the chapter in which their material would have appeared.
OCR for page 5
Global Issues in Water, Sanitation, and Health: Workshop Summary TABLE WO-1 Estimation of Mortality Due to Diarrhea in India Crude death rate (India, rural) 9.3 per 1000 population Sample Registration System Bulletin. 2001; 32 Total number of deaths 6,897,441 Total deaths in 0-6 years* 1,517,437 (22% of total rural deaths) Total deaths in >6 years* 5,380,004 (78% of total rural deaths) Crude death rate (India, urban) 6.3 per 1000 population Sample Registration System Bulletin. 2001; 32 Total number of deaths 1,797,736 Total deaths in 0-6 years* 221,122 (12.3% of total urban deaths) Total deaths in >6 years* 1,576,614 (87.7% of total urban deaths) Total deaths (all ages; rural + urban)* 8,695,177 Total 0–6 years deaths (rural + urban)* 1,738,559 Proportionate mortality due to diarrhea (all ages)* 5.23% [SBHI, 2002] Total diarrheal deaths (all ages) 454,758 Proportionate mortality due to diarrhea* (0-6 years) 9.1% [SBHI, 2002] Total diarrheal deaths among 0-6 years* 158,209 Total diarrheal deaths among 6+ years* 296,549 *Age-specific death rates: Sample Registration System, 1998. NOTE: The estimated total deaths due to diarrhea are less than the estimation of 576,480 deaths by Zaidi et al. (2004). SOURCE: National Institute of Cholera and Enteric Diseases, Kolkata (NICED, 2005) with permission from the Ministry of Health and Family Welfare, Government of India. ments for international cooperation on water issues and highlights some promising grassroots programs to improve access to safe water (see Chapter 1). In China and India, rapid economic expansion has intensified demand for increasingly polluted water. China, the film notes, contains more than one-fifth of the world’s people but only seven percent of its fresh water (Thebaut, 2005). Industrial consumption of water drains the storied Yellow River to such an extent that in drought years, it runs dry. Seventy percent of China’s rapidly growing cities lack a sewage treatment plant, and agricultural and industrial waste pollutes the country’s major reservoirs.9 Another fifth of the world’s population—and approximately half of the world’s poor—live in India, where more than 100 cities release their untreated human, animal, and industrial wastes directly into the sacred river Ganges, transforming it into an open sewer. This entirely preventable environmental catastrophe, coupled with widespread groundwater contamination, undoubtedly contributes to India’s heavy burden of death (Table WO-1) and disability (Table WO-2) from diarrheal disease. Rampant over-consumption and misuse of water occurs in the United States, with consequences that reach well beyond our borders. Despite the existence of a 9 For a good summary article, see http://www.dailywealth.com/archive/2008/aug/2008_aug_11.asp and http://www.msnbc.msn.com/id/17704190/.
OCR for page 6
Global Issues in Water, Sanitation, and Health: Workshop Summary TABLE WO-2 Data Used for Estimation of Burden Due to Diarrhea in India Indices Current Values (2001) Projected Values 2001-2006 2006-2011 2011-2016 Total Population (in crore*) 102.7 109.41 (‘06) 117.89 (‘11) 126.35 (‘16) Life expectancy at birth (years) Male 62.30 (projected) 63.87 65.65 67.04 Female 65.27 (projected) 66.91 67.67 69.18 *Crore (Hindi: (often abbreviated cr) is a unit in the Indian numbering system and was formerly a unit in the Persian numbering system, still widely used in Bangladesh, India, Maldives, Nepal, Pakistan, and Sri Lanka, and formerly in Iran. An Indian crore is equal to 100 lakh or 10,000,000. SOURCE: National Institute of Cholera and Enteric Diseases, Kolkata (NICED, 2005) with permission from the Ministry of Health and Family Welfare, Government of India. Data retrieved from the Registrar General of India, 1996. bilateral treaty—the U.S.-Mexico Water Treaty of 194410—that stipulates that the two countries will share the Colorado River’s waters, the demands of upstream users of the Colorado River—a primary source of water for seven states in the western United States—are now so great that its waters rarely reach the Sea of Cortez in Mexico (Cohen and Henges-Jeck, 2001). This is but one example among the growing number of social, political, and economic conflicts arising over access to water, according to Peter Gleick, cofounder and president of the Pacific Institute for Studies in Development, Environment, and Security (Gleick, 2001; Thebaut, 2005). Where political tensions already exist—as in the arid Middle East—competition for and access to clean water, a natural resource more valuable than oil,11 may intensify them. On the other hand, as both Shimon Peres, former Prime Minister of the State of Israel, and Nabil Sharif, Chairman of the Palestinian Water Authority, observed in Running Dry, the process of making policy to meet water needs may also offer adversaries an opening for resolving other conflicts. Extended to a global level, the necessity for international cooperation on water issues may thus be viewed as an opportunity for regional conflict resolution. Water and Health in Africa Africa poses particular challenges to providing safe, accessible water for its rapidly growing population. Although the continent, particularly in the Congo Basin, possesses abundant water resources, the majority of Africans lack access to safe water, primarily as a consequence of poverty and armed conflicts (UNICEF, 10 For more information on this treaty, please see http://www.usbr.gov/lc/region/g1000/pdfiles/mex-trety.pdf. 11 Urban Water Conference, http://www.urbanwaterconference.be/db (accessed March 13, 2009).
OCR for page 7
Global Issues in Water, Sanitation, and Health: Workshop Summary 2006). Outbreaks of cholera and other water-related diseases have been frequent occurrences, affecting the health and well-being of thousands of individuals. In sub-Saharan Africa, water resources are scarce and water availability may be seasonal. According to the World Health Organization (WHO) and United Nations Children’s Fund (UNICEF) Joint Monitoring Programme for Water Supply and Sanitation (JMP), 28 percent of the population of sub-Saharan Africa defecates in the open, and an additional 23 percent use “unimproved” sanitation facilities that “do not ensure hygienic separation of human excreta from human contact” (JMP, 2008). Moreover, even where clean water and flush toilets are available in Africa, lack of hygiene awareness continues to result in outbreaks of water-related diseases (Thebaut, 2005). Clearly, in order to benefit from advances in sanitation, people must appreciate the connection between water, sanitation, and health—a link that keynote speaker Donald Hopkins, Vice President of Health Programs at the Carter Center in Atlanta, Georgia, and his colleagues have tried to forge at the grassroots level in African communities (see Hopkins in Chapter 1). His description of two such programs with very different outcomes—one addressing trachoma in Ethiopia and the other targeting dracunculiasis (Guinea worm disease) in Ghana—revealed the importance of social factors as both catalysts and barriers to efforts to improve health in under-resourced communities by improving sanitation. Trachoma in Ethiopia Trachoma, a chronic infection of the cornea12 and conjunctiva13 caused by the bacterium Chlamydia trachomatis, is the world’s leading preventable cause of blindness (Hopkins et al., 2008). Ten percent of the global population is considered to be at risk for developing this disease, which disproportionately affects females. Trachoma is transmitted through multiple routes, including contaminated fingers, flies, and fomites14 such as dirty face cloths (Figure WO-2). The disease is currently managed through a multipronged strategy: surgery to prevent blindness in people with severe infections; antibiotics to fight infection in its early stages; educating people about the importance of proper face-washing to prevent the accumulation of discharge around the eyes; and environmental interventions such as improved sanitation to reduce populations of flies that spread the disease, and which breed mainly in human feces (Emerson et al., 2006; Hopkins, 2008; Hopkins et al., 2008). 12 The transparent, dome-shaped window covering the front of the eye (http://www.stlukeseye.com/anatomy/cornea.asp). 13 The thin, transparent tissue that covers the outer surface of the eye. It begins at the outer edge of the cornea, covering the visible part of the sclera, and lining the inside of the eyelids. It is nourished by tiny blood vessels that are nearly invisible to the naked eye (http://www.stlukeseye.com/Anatomy/Conjunctiva.asp). 14 Inanimate objects or substances that can transmit infectious organisms from one host to another.
OCR for page 8
Global Issues in Water, Sanitation, and Health: Workshop Summary FIGURE WO-2 The life cycle of trachoma. SOURCE: Reprinted from Dugger (2006). Copyright 2006 New York Times Graphics. Of the approximately 50 countries where trachoma is endemic, Ethiopia is thought to have the largest number of cases; about one-third of these occur in the country’s impoverished Amhara region (Hopkins, 2008). Because this region’s geology and ecology favored the construction of latrines from abundant wood, Amhara provided a promising target for sanitation-based interventions to combat trachoma, Hopkins explained. Working with the Amhara Regional Health Bureau, and with local Lions Clubs, the Carter Center mobilized residents to build latrines. “There came to be a competition between villages, between families, in who could build the better latrine or the faster latrine,” he recalled, with much of the momentum provided by women. They welcomed the project because women without access to latrines were self-described “prisoners of the daylight” due to cultural taboos against women defecating in the open during daylight hours, when they might be seen by a man.
OCR for page 9
Global Issues in Water, Sanitation, and Health: Workshop Summary “This feminist aspect of this problem did not become apparent until we began this intervention … [and] it was not primarily to prevent trachoma,” Hopkins observed. Women’s demand for convenience provided “enormous energy” for the project, he said, and it was efficiently harnessed by organizing tightly knit kin groups to perform work that benefited their relatives, leaving little room for corruption. As a result, the program surpassed its initial goal to build 10,000 latrines in Ethiopia in 2004 by more than eightfold, and has continued to build a cumulative total of more than 600,000 latrines, as of mid-2008 (Figure WO-3). Even with subsequent declines due to political unrest and a focus on other diseases by the Carter Center, Ethiopia is well on its way to meeting the Millennium Development Goal (MDG; Box WO-1) for providing latrines to at least half of the population by 2015 that did not have latrines in 2000, he reported. Existing latrines in Ethiopia, and also those constructed in a similar project in Niger, are being used and in some cases upgraded, Hopkins reported. “The most important thing that has happened [as a result of this initiative] has been, not so much the physical act of building the latrine, but the change in the mindset,” he concluded. The behavioral foundations of this success should be studied so it can be replicated elsewhere, he added: “What we haven’t done, and can’t really afford to do, is to get some proper anthropologists and others to go into that area and really understand, better than we do, what happened there, to see how that can be applied more broadly, perhaps even beyond Ethiopia.” Dracunculiasis in Ghana Dracunculiasis15 is caused by the nematode Dracunculus medinensis and is limited to humans, who typically ingest the parasite in water containing copepods16 that carry the worm’s larvae (Hopkins et al., 2008). After a year-long asymptomatic incubation period, worms as long as one meter emerge through the skin on any part of the host’s body, causing extreme pain that, along with frequent secondary bacterial infection, typically incapacitates patients for two to three months (see Figure WO-6). Half the population of a village may simultaneously experience these symptoms, drastically reducing school attendance and agricultural productivity. While there is no immunity to or cure for dracunculiasis, Hopkins noted, the disease could be eradicated by providing safe drinking water to vulnerable populations—a goal approached over the course of the past two decades, during which the number of infected individuals has declined from 3.5 million to 10,000 (Hopkins et al., 2008; Figures WO-7 and WO-8). Interventions included preventive health education and instruction in the use of cloth filters to remove copepods from drinking water; preventing contamination of surface water by 15 Dracunculiasis, or Guinea worm disease, is the only infectious disease that is caused exclusively by ingestion of contaminated drinking water. 16 Copepods are a type of crustacean which may live in both salt and freshwater. They are one of the most abundant animals on the planet (see http://jaffeweb.ucsd.edu/pages/celeste/Intro/index.html).
OCR for page 10
Global Issues in Water, Sanitation, and Health: Workshop Summary FIGURE WO-3 Carter Center-supported household latrine construction in Ethiopia. *2008 data are provisional, January-August. SOURCE: Courtesy of The Carter Center
OCR for page 11
Global Issues in Water, Sanitation, and Health: Workshop Summary BOX WO-1 Millennium Development Goals The Millennium Development Goals (MDGs) are based on the actions and targets contained in the Millennium Declaration, which was adopted by 189 nations and signed by 147 heads of state and governments during the UN Millennium Summit in September 2000 (UNDP, 2009). In response to the world’s primary development challenges, the MDGs are comprised of eight goals to be achieved by 2015. On water and sanitation specifically, the MDGs aim to halve the proportion of people without sustainable access to safe drinking water and basic sanitation. Basic sanitation is defined as access to, and use of, excreta and sullage* disposal facilities and services that provide privacy and dignity while at the same time ensuring a clean and healthful living environment both at home and in the immediate neighborhood of users (UN Millennium Project, 2005). The indicators of progress toward this target are the proportion of population with sustainable access to an improved drinking water source, urban and rural (Figure WO-4); and the proportion of the urban and rural population with access to improved sanitation (Figure WO-5). FIGURE WO-4 World population with and without access to an improved drinking water source in 1990, 2004, and 2015. SOURCE: Reprinted with permission from WHO/UNICEF (2006).
OCR for page 39
Global Issues in Water, Sanitation, and Health: Workshop Summary Investment, Implementation, and Entrepreneurship Investment and implementation: The World Bank perspective A deep financing gap separates investments needed for water and sanitation infrastructure and actual spending, according to speaker Vahid Alavian, of the World Bank. As Alavian observed, an estimated annual global investment of $25 to $30 billion in water and sanitation is necessary for meeting the MDG, but the world is spending only about half that amount. As the largest global investor in water and sanitation, the World Bank follows a two-pronged approach, financing water and sanitation interventions that are intended to benefit either the entire economy of a nation or its poorest citizens. In either case, the bank focuses on the long term, supporting sustainable efforts to address endemic disease in developing countries, Alavian explained. This commitment requires not only financial resources, but also support for scaling up and expanding interventions, strengthening governance and institutions, and ensuring sustainability. In Senegal, for example, before financing the recovery of a water utility from bankruptcy, the World Bank established capacity-building and sector reform to create a viable environment for their later investment. As a result, the bank’s relatively small contribution of about $500 million was leveraged into interventions that are likely to enable the country to meet the water and sanitation MDG, Alavian reported. Since people invest in water and sanitation primarily for reasons unrelated to health, and therefore health improvement is not a priority for the design, construction, and operation of water supply and sanitation infrastructure, the World Bank must determine how to make investments in such projects as beneficial as possible from a public health standpoint, Kolsky said. This already difficult challenge is further complicated by the differing agendas of various sectors (e.g., health, urban development, utility, environment) involved in water and sanitation (see Boeston et al. in Chapter 4). Kolsky maintained, however, that when incorporated into water and sanitation projects from their inception, health interventions are relatively inexpensive to implement. Kolsky concluded, therefore, that “we need to build our public health perspective early on in project design, and we need to think about water and wastes and behavior.” Kolsky described one example of such a design process, which resulted from the discovery by an urban planner in India that plans to construct water infrastructure to serve a city center involved laying pipes through a slum area. Based on his determination that the cost of connecting the slum neighborhoods to the planned sewer and water network was negligible relative to the overall expense of the project, the planner was able to convince government officials to extend the benefits of the new network to the city’s poorest residents. Social entrepreneurship Much as distributed energy systems and micro-financing encourage the development of small-scale solutions for water and sani-
OCR for page 40
Global Issues in Water, Sanitation, and Health: Workshop Summary tation in developing countries, social entrepreneurship can provide the impetus for communities to use these tools to address their particular public health needs, explained speaker Sharon Hrynkow of the National Institute of Environmental Health Sciences (NIEHS). Through a series of examples—ranging in scale from an NIEHS Superfund28 basic research program on the remediation of arsenic-tainted wells in India to a community-run pay toilet organization in Indonesia—Hrynkow illustrated the tenets of social entrepreneurship as they apply to the development of water and sanitation interventions (see Chapter 4). Instead of viewing communities simply as beneficiaries of received services, a social entrepreneur recognizes a collection of experts who can judge the appropriateness of interventions and sustain successful ones, she said. This perspective, which is not shared by medical researchers, offers a means to better understand why certain communities accept and develop new technologies, Hrynkow observed. To gain this perspective, she recommended that public health practitioners work more closely with social entrepreneurs (“we can put them on our boards, in our public slots; we can link them to our researchers on the ground in foreign countries”) and use their ideas and enthusiasm to engage the next generation of public health researchers. Needs and Opportunities Central Themes Over the course of the two days of this workshop, discussions returned to three main themes that underlie needs and opportunities for reducing the burden of water-related infectious diseases. The distillation of these discussion “themes” inform subsequent, specific considerations described below regarding the research agenda, opportunities for public heath intervention, infrastructure development and improvement, and strategic approaches to addressing issues in water, sanitation, and health. They are not, nor should they be interpreted to be, conclusions or recommendations arrived at through a deliberative consensus study process. Global phenomena, local effects While the global water crisis may be viewed as a byproduct of interdependent global phenomena that includes population growth, industrialization, climate change, and urbanization, its impact on public health is locally variable, necessitating local solutions. Ecological factors contributing to infectious disease emergence are particularly influential in the case of water-related diseases. 28 Superfund is the U.S. government’s program to clean up the nation’s uncontrolled hazardous waste sites. For more information, see http://www.epa.gov/superfund/.
OCR for page 41
Global Issues in Water, Sanitation, and Health: Workshop Summary Route and scale Each of the various water-related disease transmission processes can be interrupted at multiple points, permitting intervention on a range of geographic scales. Effective water and sanitation infrastructure is both appropriately scaled and sustainable for a given setting. Human behavior From the implementation of individual interventions, to the resolution of border conflicts over water access, to international cooperation necessary to avert a global water crisis, success depends upon human actions and interactions motivated by diverse factors, of which a scientifically sound assessment of risk and benefit is but one. Interventions to Address Water-Related Diseases Interventions to improve health by increasing water quality, sanitation, and hygiene can be implemented at many points throughout the water distribution system, from source to household to consumer. As discussed by Clasen and Cairncross (2004), these interventions include the following: source water protection; removal of pathogens by physical methods (e.g., filtration, adsorption, and sedimentation), chemical treatment (e.g., assisted sedimentation, chemical disinfection, and ion exchange), or heat and UV radiation; maintaining the microbiological quality of safe drinking water through piped distribution, residual disinfection, and improved storage; steps to encourage proper disposal of human feces; increased access to and availability of safe water; and hygienic practices within domestic and community settings, such as handwashing. Convenient access to “improved” water in quantity encourages better hygiene and limits the spread of diarrheal disease. Diarrheal disease morbidity may also be dramatically reduced by relatively simple interventions, as illustrated in Figure WO-16 (Cairncross and Valdmanis, 2006; WHO/UNICEF, 2005). Placing a water tap close to a home nearly doubles the odds of a mother cleaning her hands after contact with fecal material from a child. Poor women who spend hours per day collecting water usually view the time-saving aspect of an improved water supply as its greatest benefit. Similarly, access to even basic forms of improved sanitation, such as pit latrines, helps prevent exposures to diseases such as diarrhea, intestinal worm parasites, and trachoma. This outcome may result from improved hygiene practices that accompany better sanitation, which are also associated with social advantages such as higher status in the community, safety, convenience, and privacy.
OCR for page 42
Global Issues in Water, Sanitation, and Health: Workshop Summary FIGURE WO-16 Reduction in diarrheal diseases morbidity resulting from improvements in drinking water and sanitation services. SOURCE: Based on data in Fewtrell et al. (2005), and reprinted from WHO/UNICEF (2005) with permission from the World Health Organization. In areas where the water supply is adequate, the adoption of simple and inexpensive methods to improve the microbiological quality of existing water supplies can significantly mitigate the disease burden due to diarrheal diseases. Many point-of-use interventions, such as filtration, disinfection with radiation, boiling or chlorine, or simply the provision of enclosed, protected containers have been shown to be effective (interestingly, the use of a combination of methods simultaneously was not shown to have any added benefit; Clasen et al., 2006; Fewtrell et al., 2005). However, any intervention or provision of clean water and sanitation will only be successful if it is used. Education of the population, as well as considerations of cost, accessibility, and acceptability of interventions, will be key issues in the design and implementation of these interventions. According to the second edition of the report Disease Control Priorities in Developing Countries (Cairncross and Valdmanis, 2006), the main health ben-
OCR for page 43
Global Issues in Water, Sanitation, and Health: Workshop Summary efit of water supply, sanitation, and hygiene is a reduction in diarrheal disease. However, the effect on the incidence and prevalence of other diseases, such as dracunculiasis, schistosomiasis, and trachoma, is substantial. Water, sanitation, and hygiene improvements could eliminate 3 to 4 percent of the global burden of disease (Cairncross and Valdmanis, 2006). Sustained interventions to reduce vector-borne diseases fall into three main categories (Prüss-Üstün et al., 2008): Modifying the environment to permanently change the land, water or vegetation in ways that reduce vector habitats such as drainage, leveling land, contouring reservoirs, and altering river boundaries; Manipulating the environment to create temporary (and often repeated) unfavorable conditions for vector propagation by such means as removing aquatic plants that shelter mosquito larvae, alternately flooding and drying irrigated paddy fields, periodic flushing of natural and human-made waterways, and the introduction of predators, such as larvivorous fish; and Modifying or manipulating human habitation or behavior to reduce contact between humans and vectors with barriers such as window screens and nontreated mosquito nets, as well as by removing standing water in or near the home, which provide mosquito breeding sites. The effectiveness of these and other interventions, such as sanitation and water quality management, to reduce the burden of water-related diseases will be strongly influenced by local conditions, which must be taken into account in order to make cost-effective choices to address water-related health risks in diverse contexts (Clasen and Cairncross, 2004). Costs and Benefits of Interventions The estimated global economic benefits of drinking water and sanitation improvements include (Prüss-Üstün et al., 2008) health-care savings of $7 billion per year for health agencies and $340 million for individuals; productivity gains of nearly $10 billion per year; time savings equivalent to $63 billion per year; and values of deaths averted (based on discounted future earnings) of more than $3 billion per year. Taking these gains into account, an investment of $11.3 billion per year, as required to meet MDG7 sanitation and drinking water targets, would produce a return of approximately $84 billion.
OCR for page 44
Global Issues in Water, Sanitation, and Health: Workshop Summary Nevertheless, responding to recent shortfalls in progress toward achieving the water and sanitation targets of the MDG7, the editors of the Lancet observed that, despite such reports, most government donations to water and sanitation initiatives have not increased, nor are foundations or organizations “lining up to give money to build toilets or to fund education programmes to teach small children how to wash their hands” (Editorial, 2006). Moreover, the editorial continued, “the health-care community also seems to have lost sight of how fundamental clean water and sanitation are to health, preferring to get involved in more directly medical interventions, such as access to drugs and vaccines. It is dangerously short sighted to pour immense time and resources into vaccinating children only for them to die a few years later from diarrhoeal illnesses.” A Public Health Research Agenda Workshop participants, most notably speakers Beach, Rose, Bradley, and Forum member Rima Khabbaz of the CDC, identified and discussed the following bulleted points as particularly important examples of water-health relationships that merit further exploration, including: What are the infectious disease risks associated with agricultural water uses? What are the direct and indirect connections between water and respiratory disease? What role does handwashing play in reducing the prevalence and incidence of respiratory diseases in the developing and developed world? What are the infectious disease risks associated with the unregulated components of the water distribution “system,” including but not limited to private systems (private community and individual wells) and premise plumbing? Workshop speakers Michael Beach, David Bradley, Kelly Reynolds, and Philip Singer also discussed the need for more information on the short- and long-term health and environmental consequences associated with individual exposures to water-associated diseases as well as the health and economic impacts associated with endemic water-related diseases. In particular, presenter David Bradley—who developed the Bradley Classification Scheme for water-related diseases in the 1970s—believed that additional factors could be incorporated into his original classification scheme to include behavioral and spatial aspects of changing or modifying water sources. These factors might add additional levels of complexity to our collective appreciation of the linkages between water, sanitation, and health. It was felt by presenter Reynolds that such knowledge could inform risk assessment methods development activities, and the design and priori-
OCR for page 45
Global Issues in Water, Sanitation, and Health: Workshop Summary ties placed on different intervention strategies to reduce the health and economic impacts associated with these vector- and non-vector-borne diseases. Conclusion Safe water and sanitation pose universal challenges for public health. While global and regional phenomena such as climate change and geopolitical shifts threaten to intensify these challenges, effective solutions demand attention to local needs and opportunities. As Running Dry hopefully suggests, “most of the water crisis issues can be solved by a coordinated, global, environmentally sensitive, humanitarian effort.” REFERENCES Arnold, B. F., and J. M. Colford, Jr. 2007. Treating water with chlorine at point-of-use to improve water quality and reduce child diarrhea in developing countries: a systematic review and meta-analysis. American Journal of Tropical Medicine and Hygiene 76(2):354-364. Bartram, J., K. Lewis, R. Lenton, and A. Wright. 2005. Focusing on improved water and sanitation for health. Lancet 365(9461):810-812. Black, R. E., S. S. Morris, and J. Bryce. 2003. Where and why are 10 million children dying every year? Lancet 361(9376):2226-2234. Bostoen, K., P. Kolsky, and C. Hunt. 2007. Improving urban water and sanitation services: health, access and boundaries. In Scaling urban environmental challenges: from local to global and back, edited by P. M. Marcotullio and G. McGranahan. London: Earthscan Publications. Bowen, A., H. Ma, J. Ou, W. Billhimer, T. Long, E. Mintz, R. M. Hoekstra, and S. Luby. 2007. A cluster-randomized controlled trial evaluating the effect of a handwashing-promotion program in Chinese primary schools. American Journal of Tropical Medicine and Hygiene 76(6):1166-1173. Cairncross, S., and R. Feachem. 1993. Environmental health engineering in the tropics (2nd edition). Chichester, UK: John Wiley & Sons. Cairncross, S., and V. Valdmanis. 2006. Water supply, sanitation, and hygiene promotion. In Disease control priorities in developing countries (2nd edition), edited by D. T. Jamison, J. G. Breman, A. R. Measham, G. Alleyne, M. Claeson, D. B. Evans, P. Jha, A. Mills, and P. Musgrove. New York: Oxford University Press. Calvin, L 2007. Outbreak linked to spinach forces reassessment of food safety practices. AmberWaves Magazine (USDA Economic Research Service), http://www.ers.usda.gov/AmberWaves/June07/Features/Spinach.htm(accessed March 11, 2009). CDC (Centers for Disease Control and Prevention). 2009. Outbreak of Salmonella serotype Saintpaul infections associated with eating alfalfa sprouts—United States, 2009. Morbidity and Mortality Weekly Report 58(18):500-503. Clasen, T. F. 2008. Scaling up household water treatment: looking back, seeing forward. Geneva: World Health Organization. Clasen, T. F., and S. Cairncross. 2004. Household water management: refining the dominant paradigm. Tropical Medicine and International Health 9(2):187-191. Clasen, T. F., I. Roberts, T. Rabie, W. Schmidt, and S. Cairncross. 2006. Interventions to improve water quality for preventing diarrhoea. Cochrane Database of Systematic Reviews 3. Art. No. CD004794.
OCR for page 46
Global Issues in Water, Sanitation, and Health: Workshop Summary Clasen, T. F., L. Haller, D. Walker, J. Bartram, and S. Cairncross. 2007a. Cost-effectiveness of water quality interventions for preventing diarrhoeal disease in developing countries. Journal of Water and Health 5(4):599-608. Clasen, T. F., W. P. Schmidt, T. Rabie, I. Roberts, and S. Cairncross. 2007b. Interventions to improve water quality for preventing diarrhoea: systematic review and meta-analysis. British Medical Journal 334(7597):782. Clasen, T. F., C. McLaughlin, N. Nayaar, S. Boisson, R. Gupta, D. Desai, and N. Shah. 2008. Microbiological effectiveness and cost of disinfecting water by boiling in semi-urban India. American Journal of Tropical Medicine and Hygiene 79(3):407-413. Cohen, M. J., and C. Henges-Jeck. 2001. Missing water: the uses and flows of water in the Colorado River delta region. Oakland, CA: Pacific Institute for Studies in Development, Environment, and Security. Colwell, R. R. 2004. Infectious disease and environment: cholera as a paradigm for waterborne disease. International Microbiology 7(4):285-289. Curriero, F. C., J. A. Patz, J. B. Rose, and S. Lele. 2001. The association between extreme precipitation and waterborne disease outbreaks in the United States, 1948-1994. American Journal of Public Health 91(8):1194-1199. Dugger, C. W. 2006. Preventable disease blinds poor in third world. New York Times, March 31. Editorial. 2006. Water and sanitation: the neglected health MDG. Lancet 368(9543):1212. Emerson, P. M., M. Burton, A. W. Solomon, R. Bailey, and D. Mabey. 2006. The SAFE strategy for trachoma control: using operational research for policy, planning and implementation. Bulletin of the World Health Organization 84(8):613-619. Feachem, R. G., D. J. Bradley, H. Garelick, and D. D. Mara. 1983. Sanitation and disease: health aspects of excreta and wastewater management. Chichester, UK: John Wiley. Fewtrell, L., R. B. Kaufmann, D. Kay, W. Enanoria, L. Haller, and J. M. Colford, Jr. 2005. Water, sanitation, and hygiene interventions to reduce diarrhoea in less developed countries: a systematic review and meta-analysis. Lancet Infectious Diseases 5(1):42-52. George, Rose. 2008. The big necessity: the unmentionable world of human waste and why it matters. New York: Henry Holt and Company. Gil, A. I., V. R. Louis, I. N. Rivera, E. Lipp, A. Huq, C. F. Lanata, D. N. Taylor, E. Russek-Cohen, N. Choopun, R. B. Sack, and R. R. Colwell. 2004. Occurrence and distribution of Vibrio cholerae in the coastal environment of Peru. Environmental Microbiology 6(7):699-706. Gleick, P. H. 2001. Making every drop count. Scientific American (February):28-33. Hopkins, D. R. 2008. Improving water, sanitation, and health at the grassroots. Paper presented at the Global Issues in Water, Sanitation, and Health workshop, Washington, DC, September 23-24, 2008. Hopkins, D. R., F. O. Richards, Jr., E. Ruiz-Tiben, P. Emerson, and P. C. Withers, Jr. 2008. Dracunculiasis, onchocerciasis, schistosomiasis, and trachoma. Annals of the New York Academy of Sciences 1136:45-52. Hoyois, P., J.-M. Scheuren, R. Below, and D. Guha-Sapin. 2007. Annual disaster statistical review: numbers and trends 2006. Brussels: Center for Research on the Epidemiology of Disasters. Hrudey, S. E., and E. J. Hrudey. 2007. Published case studies of waterborne disease outbreaks—evidence of a recurrent threat. Water Environment Research 79(3):233-245. Hrudey, S. E., and R. Walker. 2005. Walkerton, 5 years later: tragedy could have been prevented. Opflow 31(6):1-5. IOM (Institute of Medicine). 2006. Addressing foodborne threats to health: policies, practices, and global coordination. Washington, DC: The National Academies Press. ———. 2008. Global climate change and extreme weather events: understanding the contributions to infectious disease emergence. Washington DC: The National Academies Press. ———. 2009. Microbial evolution and co-adaptation: a tribute to the life and scientific legacies of Joshua Lederberg. Washington, DC: The National Academies Press.
OCR for page 47
Global Issues in Water, Sanitation, and Health: Workshop Summary IPCC (Intergovernmental Panel on Climate Change). 2008. Linking climate change and water resources: impacts and responses. In Climate change and water, edited by B. C. Bates, Z. W. Kundzewicz, S. Wu, and J. P. Palutikof. Technical Paper of the Intergovernmental Panel on Climate Change. Geneva: IPCC. JMP (Joint Monitoring Programme for Water Supply and Sanitation). 2008. Progress on drinking water and sanitation: special focus on sanitation. New York and Geneva: UNICEF and WHO. Liang, J. L., E. J. Dziuban, G. F. Craun, V. Hill, M. R. Moore, R. J. Gelting, R. L. Calderon, M. J. Beach, and S. L. Roy. 2006. Surveillance for waterborne disease and outbreaks associated with drinking water and water not intended for drinking—United States, 2003-2004. Morbidity and Mortality Weekly Report 55(SS12):31-58. Lipp, E. K., A. Huq, and R. R. Colwell. 2002. Effects of global climate on infectious disease: the cholera model. Clinical Microbiology Reviews 15(4):757-770. Lule, J. R., J. Mermin, J. P. Ekwaru, S. Malamba, R. Downing, R. Ransom, D. Nakanjako, W. Wafula, P. Hughes, R. Bunnell, F. Kaharuza, A. Coutinho, A. Kigozi, and R. Quick. 2005. Effect of home-based water chlorination and safe storage on diarrhea among persons with human immunodeficiency virus in Uganda. American Journal of Tropical Medicine and Hygiene 73(5):926-933. Mac Kenzie, W. R., N. J. Hoxie, M. E. Proctor, M. S. Gradus, K. A. Blair, D. E. Peterson, J. J. Kazmierczak, D. G. Addiss, K. R. Fox, J. B. Rose, and J. P. Davis. 1994. A massive outbreak in Milwaukee of cryptosporidium infection transmitted through the public water supply. New England Journal of Medicine 331(3):161-167. Miles, S. L., C. P. Gerba, I. L. Pepper, and K. A. Reynolds. 2008. Point-of-use drinking water devices for assessing microbial contamination in finished water and distribution systems. Environmental Science and Technology 43(5):1425-1429. Mittelstaedt, M. 2009 (March 12). UN warns of widespread water shortages. Globe and Mail, http://www.theglobeandmail.com/servlet/story/RTGAM.20090311.wwater0312/BNStory/International/home (accessed April 22, 2009). NICED (National Institute of Cholera and Enteric Diseases, Kolkata). 2005. Estimation of the burden of diarrhoeal diseases in India. In National Commission on Macroeconomics and Health background papers—burden of disease in India. New Delhi: Ministry of Health and Family Welfare. Northern Territory Government, Department of Health and Families. 2009. The Northern Territory Public Health Bush Book. Darwin: Northern Territory Government, Department of Health and Families, http://www.nt.gov.au/health/healthdev/health_promotion/bushbook/volume2/chap2/intro.htm (accessed May 18, 2009). NRC (National Research Council). 1993a. Managing wastewater in coastal urban areas. Washington, DC: National Academy Press. ———. 1993b. Soil and water quality: an agenda for agriculture. Washington, DC: National Academy Press. ———. 2002. Countering bioterrorism: the role of science and technology. Washington, DC: National Academy Press. ———. 2004a. Review of the desalination and water purification technology roadmap. Washington, DC: The National Academies Press. ———. 2004b. Water and sustainable development: opportunities for the chemical sciences—a workshop report to the Chemical Sciences Roundtable. Washington, DC: The National Academies Press. ———. 2004c. Confronting the nation’s water problems: the role of research. Washington, DC: The National Academies Press. ———. 2005. Water conservation, reuse, and recycling: proceedings of an Iranian-American workshop. Washington, DC: The National Academies Press.
OCR for page 48
Global Issues in Water, Sanitation, and Health: Workshop Summary ———. 2006. Drinking water distribution systems: assessing and reducing risks. Washington, DC: The National Academies Press. ———. 2007. Colorado River basin water management: evaluating and adjusting to hydroclimatic variability. Washington, DC: The National Academies Press. ———. 2008a. Desalination: a national perspective. Washington, DC: The National Academies Press. ———. 2008b. Prospects for managed underground storage of recoverable water. Washington, DC: The National Academies Press. ———. 2008c. Urban stormwater management in the United States. Washington, DC: The National Academies Press. O’Reilly, C. E., M. C. Freeman, M. Ravani, J. Migele, A. Mwaki, M. Ayalo, S. Ombeki, R. M. Hoekstra, and R. Quick. 2008. The impact of a school-based safe water and hygiene programme on knowledge and practices of students and their parents: Nyanza Province, western Kenya, 2006. Epidemiology and Infection 136(1):80-91. Osterholm, M. T. 2006. The food supply and biodefense: the next frontier of the food safety agenda. In Addressing foodborne threats to health: policies, practices, and global coordination. Washington, DC: National Academy Press. Parker, A. A., R. Stephenson, P. L. Riley, S. Ombeki, C. Komolleh, L. Sibley, and R. Quick. 2006. Sustained high levels of stored drinking water treatment and retention of hand-washing knowledge in rural Kenyan households following a clinic-based intervention. Epidemiology and Infection 134(5):1029-1036. Pond, K. 2005. Water recreation and disease. plausibility of associated infections: acute effects, sequelae and mortality. London: IWA Publishing on behalf of the World Health Organization. Prüss-Üstün, A., R. Bos, F. Gore, and J. Bartram. 2008. Safer water, better health: costs, benefits and sustainability of interventions to protect and promote health. Geneva: World Health Organization. Seas, C., J. Miranda, A. I. Gil, R. Leon-Barua, J. Patz, A. Huq, R. R. Colwell, and R. B. Sack. 2000. New insights on the emergence of cholera in Latin America during 1991: the Peruvian experience. American Journal of Tropical Medicine and Hygiene 62(4):513-517. Thebaut, J. 2005. Running dry. Produced and directed by J. Thebaut. Redondo Beach, CA: The Chronicles Group. DVD. UN (United Nations). 2009. World water development report 3: water in a changing world. New York: UNESCO and Earthscan. UN Millennium Project. 2005. Health, dignity, and development: what will it take? UN Millennium Project Task Force on Water and Sanitation. London and Sterling, VA: Earthscan. UNDESA (United Nations Department of Economic and Social Affairs). 1992. Agenda 21 earth summit: United Nations program of action from Rio. New York: United Nations. UNDP (United Nations Development Programme). 2009. About the MDGs: basics, http://www.undp.org/mdg/basics.shtml (accessed March 17, 2009). UNESCO (United Nations Educational, Scientific and Cultural Organization). 2006. Water, a shared responsibility: the United Nations world water development report 2. New York: UNESCO/Berghahn Books. UNICEF (United Nations Children’s Fund). 2006. Progress for children: a report card on water and sanitation. New York: UNICEF. van der Werf, M. J., S. J. de Vlas, S. Brooker, C. Looman, N. Nagelkerke, J. Habbema, and D. Engels. 2003. Quantification of clinical morbidity associated with schistosome infection in sub-Saharan Africa. Acta Tropica 86(2-3):125-139. Wagner, E. G., and J. N. Lanoix. 1958. Excreta disposal for rural areas and small communities. WHO monograph series. P. 39. White, G. F., D. J. Bradley, and A. U. White. 1972. Drawers of water: domestic water use in East Africa. Chicago: University of Chicago Press.
OCR for page 49
Global Issues in Water, Sanitation, and Health: Workshop Summary WHO (World Health Organization). 2008a. Dengue and dengue hemmorhagic fever fact sheet, http://www.who.int/mediacentre/factsheets/fs117/en/ (accessed August 10, 2008). ———. 2008b. Human african trypanosomiasis, http://www.who.int/trypanosomiasis_african/disease/en/index.html (accessed August 10, 2008). ———. 2008c. Initiative for vaccine research: schistosomiasis, http://www.who.int/vaccine_research/diseases/soa_parasitic/en/index5.html (accessed August 10, 2008). ———. 2008d. International network to promote household water treatment and safe storage, http://www.who.int/household_water/network/en/ (accessed March 27, 2008). ———. 2008e. Malaria fact sheet, http://www.who.int/mediacentre/factsheets/fs094/en/index.html (accessed August 10, 2008). ———. 2008f. Onchocerciasis disease information, http://www.who.int/tdr/diseases/oncho/diseaseinfo.htm (accessed August 10, 2008). WHO/UNICEF. 2005. Water for life: making it happen. Geneva: WHO/UNICEF. ———. 2006. Meeting the MDG water and sanitation target: the urban and rural challenge of the decade. New York and Geneva: UNICEF and WHO. Wright, J., S. Gundry, and R. Conroy. 2004. Household drinking water in developing countries: a systematic review of microbiological contamination between source and point-of-use. Tropical Medicine and International Health 9(1):106-117. www.Data360.org. 2009. Average water use per person per day, http://www.data360.org/dsg.aspx?Data_Set_Group_Id=757 (accessed June 3, 2009). Zaidi, A. K. M., S. Awasthi, and H. J. deSilva. 2004. Burden of infectious diseases in South Asia. British Medical Journal 328(7443):811-815.