Meeting Report

In most places in the developed world, we take high-quality potable water for granted. It comes out of our taps and flushes away our waste 24 hours a day, 7 days a week, 365 days a year, raising little concern that it will cause us harm. But in many places, ensuring that people have access to sufficient supplies of clean water has become one of the great challenges of the 21st century.

The UN Commission on Sustainable Development projects that demand for water will double by the middle of this century, and increase at a rate of 50% with each subsequent generation. Africa, the Middle East, and Asia are likely to be particularly vulnerable, and it is estimated that the portion of humanity that will not have access to sufficient or clean water supplies will increase from 1/3 to 2/3. Even in the United States, regions spanning a wide band in the South are facing increased threat of water shortages.

Today approximately one-half of all hospitalizations around the world are due to waterborne diseases. Nearly 2.5 billion people have poor sanitation, and lack of access to sufficient water supplies is implicated in approximately half of all malnutrition. Because many people have no choice but to use the same water supplies for both drinking and sanitary purposes, waterborne diseases such as cholera, typhus, E. coli infection, and dysentery are a constant threat in many places, with children paying a particularly high toll. Meanwhile, population growth and climate change threaten to make all of these factors much worse.

"In effect, we are on countdown," remarked Erik Peterson, director of the Center for Strategic & International Studies, at a November 13, 2009, NYAS symposium organized in collaboration with the Johns Hopkins Bloomberg School of Public Health. The meeting featured four experts who provided a wide-ranging set of perspectives on the importance of water in our lives, from its role in global social, economic, and political trends, all the way down to the individual human cell.

Water, global policy, and international security

One of the most disturbing things Peterson finds about water is the global community's inability to understand the magnitude of the problem it poses, and to develop effective public policy for managing the resource. At the same time that patterns of water usage have become unsustainable, he pointed out, there is no commonly accepted pricing and allocation structure, and only limited understanding of how sectors like energy and agriculture are dependent on water availability.

Water is thus not only a public health and environmental issue, but affects social relations, economic prosperity, and—with 260 basins around the world shared by more than two countries—an increasingly important strategic issue. "Clearly, we need to find a better way to build [into] the public policy sphere this critical resource that affects so many people at so many levels," Peterson argued.

Particularly in the developing world, water shortages have many implications for development. Peterson cited data from the United Nations and World Bank about Ethiopia that correlated reductions in gross domestic product with years of less rainfall. Lack of access to safe drinking water and sanitation services also has huge opportunity costs. UNICEF has suggested that lack of sanitary facilities at schools is an important reason for girls' high dropout rates in sub-Saharan Africa. A UN survey of 177 countries also determined that women lose approximately 40 billion working hours each year walking long distances to fetch water for their families.

The challenge of ensuring access to sufficient water is complicated by the fact that energy production is dependent on water availability. As population grows, energy demands are also growing, which means the energy sector will need more water to meet everyone's needs. Peterson pointed out that policymakers considering investments in nuclear power generation need to understand that it requires significantly more water than other generating methods. "As we see countries trying to find energy solutions for increasing populations," he said, "they'll need to be thinking long and hard about how to find sufficient water to deal with that increased energy production."

Some important interactions between water, energy, and agriculture (slide courtesy of Erik Peterson).

Similarly, with 70% of worldwide water use going to agriculture, the dynamic links between water, energy, and farming could lead to political instability. Citing the protests that occurred in the spring of 2008 when rising fuel costs caused food prices to spike, Peterson forecast, "As the global economy revives, the likelihood is that [with] additional increases in demand, especially in the areas of energy and food, we're likely to see the geopolitics of resources assume ever sharper definition."

Developments such as these suggest that there is an "ironclad case" for making water a core element of an integrated international policy strategy in the United States, Peterson said. There is a spectrum of goals and interests in relation to water, from human health, to humanitarian aid, to gender equality, to economic development, to environmental sustainability, to geopolitical stability, although currently there is only minimal integration among the various federal agencies for whom water is a concern.

In a CSIS report published in 2008 with coauthor Rachel Posner, Peterson recommends creating a new Bureau for International Water Policy that be tasked with "speaking for water" in collaboration with the U.S. State Department, the United States Agency for International Development (USAID), and other policy-making bodies. Developing an integrated, far-sighted water policy would recognize that addressing the issue is not just altruism, but is very important to national interests—particularly, he concluded, because "these pressures are growing by the day."

Cholera and climate change

Environmental microbiologist Rita Colwell has studied cholera for 40 years, and sees it as a case study for understanding a disease caused by an environmental bacterium, coupled with the effects of poor sanitation on human health. The cholera story is also one that she sees as emblematic of the ways in which climate change could exacerbate current challenges posed by infectious diseases.

Cholera is caused by ingestion of the bacterium Vibrio cholerae, which replicates in the small intestine of humans. Toxins produced by V. cholerae cause massive loss of fluid and death within hours if not treated. It is an ancient disease and the causative agent, Vibrio cholerae, is found in aquatic environments in many parts of the world. Cholera, in some years, causes approximately 250,000 deaths. In Zimbabwe, an ongoing cholera epidemic that public health officials have connected to corruption in the Mugabe government has had a fatality rate of 30%–40% in some parts of the country.

Although researchers once believed that the only mode of transmission of cholera was from person to person, Colwell and her colleagues have ascertained that Vibrio cholerae is associated with seasonal zooplankton and phytoplankton blooms. These creatures proliferate when seas warm, and can move up into rivers when sea levels rise. These factors combine to cause cholera outbreaks seasonally, typically in spring and fall, when humans ingest water containing the Vibrio-carrying organisms.

Two sets of graphs comparing epidemiologic data (black) with Colwell's team's predictive models (blue and red) in Kolkata, India and Matlab, Bangladesh.

Using satellite-based remote sensing to observe factors such as sea level fluctuations, the presence of chlorophyll, and water temperature, Colwell and her colleagues are developing models to predict cholera epidemics in Bangladesh, India, and Senegal months before they occur. What they have discovered reflects the important role of the aquatic world for human health. "The effect of poor sanitation is, of course, person-to-person transmission, but the source is really the environment," Colwell observed. "This tells us that we are very intertwined with the environment and that water is fundamental to our lives and health. If we do not have access to safe water, we have a devastatingly serious health problem."

Warming and rising seas threaten to make these problems worse, not only from the perspective of disease, but also with regard to the habitability of many low-lying areas of the world. Colwell remarked, "It grieves me to have to point out that with a predicted one-meter rise in sea level, we are going to see 17%–20% of Bangladesh permanently underwater, which means that we will have perhaps 100 million climate change refugees. Furthermore, if the glaciers in the Himalayas recede to the point of disappearance, we will have a water shortage of immense proportions occurring in this country, which already suffers as one of the poorest, economically, in the world."

Water issues in the United States

Although the areas most threatened by water shortages and contamination are in the developing world, Kellogg Schwab, director of the Johns Hopkins Center for Water and Health, reminded the audience that "if you look within the United States, we have extreme water needs within our own country.... It's not an 'us-them' issue, it's a 'we' issue."

Much of the country benefits from an abundance of rain, but areas including California, the Atlanta area, and the Southwest have faced dangerous droughts in recent years. Moreover, much of the nation's water infrastructure is aging and fragile, and will be very expensive to upgrade. And even if the arrival of chlorinated drinking water in the early 1900s effectively ended the era when Americans had to fear dying from cholera or typhoid, a host of emerging contaminants in the U.S. water supply—including pharmaceuticals, endocrine disrupting compounds, methyl tertiary butyl ether (MTBE), tetrachloroehtylene (TCE), and bisphenol A—are posing new kinds of health threats.

Schwab sees a paradox at the core of the water problem. "I attest to you that water is an inalienable right for every one of us," he asserted. At the same time, however, those who own water rights defend them vigorously, and "to produce high-quality, potable water takes money, resources, and energy." Ongoing debate is exploring the question of how to account for this fundamental economic issue, and whether passing the true costs of extraction and delivery along to users could help ensure accountability and financial sustainability.

Technologies for the developing world

Schwab pointed out that a variety of existing technologies—including clay pots, membrane filtration, and community water treatment plants—can improve sanitation in the developing world. The challenge is how to deliver these devices to communities in ways that effectively address their needs.

One new approach that engineers have begun to investigate is whether aquaporins could be used to filter contaminants from water. Peter Agre was awarded the 2003 Nobel Prize in Chemistry for discovering aquaporins, channels in the cell membrane that allow water to move inside the cell without resistance. At the Academy he provided an overview of the roles of various aquaporin subtypes in human health, and their vital roles in maintaining water equilibrium in the body. Aquaporin dysfunction in this class of proteins is implicated in a range of conditions, including pulmonary capillary defects, diabetes, congenital cataracts, malaria, and hyperthermia.

Schwab explained that researchers at Hopkins and elsewhere are exploring whether it might be possible to create a living membrane made of auquaporins that would exclude everything except H₂O. This approach would be high-tech in the laboratory, but if developed well, could be low-tech, and therefore more practical, in the field.

Demonstration of a simple water filtration method in Bangladesh. Photo courtesy of Rita Colwell.

Referring to her team's discovery of the role of plankton in cholera, Rita Colwell also described a low-tech intervention they conducted to help defend villagers in Bangladesh against the disease. After testing its effectiveness in the laboratory, they conducted a three-year study educating the women to fold old sari cloth, the material used to make their dresses, over the openings of their pots when gathering water for their families. "We found that we could reduce cholera 50% by this simple filtration technique," she explained. Their effort had a persistent effect, and as word spread, control villages started filtering as well. The strategy helped to reduce the incidence of cholera even in local homes that did not filter due to the herd effect on disease transmission. Colwell is also working with Abdul Hassam, a colleague in Bangladesh, on another low-cost filtration technique to remove arsenic from well water.

Behavioral interventions can also have an effect in the West. Schwab encouraged the audience to be aware of their water consumption. In the United States, where a flush of the toilet is equal to the volume of water consumed by a person in many parts of the world in a day, personal decisions that can help conserve water are also important. In the question and answer period following the formal lectures, discussion considered the roles that taxation, financial incentives, and better education could play in reducing water use.

If there was an overarching message to the meeting, it was that solving the problem of delivering safe water will only occur with a focused, forward-thinking, and interdisciplinary effort. As Colwell observed, the problem "is a scientific, a social behavioral, an economic, an engineering, and a political problem, and you need all these dimensions. This means it's a tough problem, but it's a problem that has to be solved."

Open Questions

Technologies such as canal lining, drip irrigation, desalination, and drought-resistant seeds can reduce water consumption by agriculture. What policies could promote their more widespread adoption?

How can resources be better mobilized to promote the availability of cheap, high-impact technologies for purifying water in developing countries?

What balance of taxation, financial incentives, regulation, and education could effectively promote more sustainable water use practices?

How can greywater recycling, which reduces the energy needed to purify water by using non-potable water for non-drinking uses, be better integrated into residential and commercial buildings?

In 2009, the ASCE gave the U.S. water infrastructure a grade of D-, suggesting that major investments are needed. Will sufficient resources be allocated to make the necessary upgrades? If not, what will the results be?

To date, Erik Peterson's proposals for a new federal bureau focused on water have not received strong support in Congress. Will the federal government develop a more focused and better integrated international water policy?

Could models of water conservation such as those seen in Israel and Singapore be applied in other regions?