The pictures — of children with sunken eyes and shriveled skin; oxen being herded across a river where women clean their clothes and fill their pitchers; an African villager sipping water from a shallow puddle — made the point like no words could at the May 11 Center for International Development symposium “The Impact of the Global Water Crisis on Health and Human Development” at the Harvard School of Public Health (HSPH). Still, the statistics were almost equally startling: More than a billion people worldwide lack safe water sources, and 2.6 billion — 40 percent of the world’s population — have no basic sanitation. Nearly 2 million people a year, 90 percent of them children under 5, die from dehydration and associated malnutrition and microbial diseases.

The conference got under way with an introductory talk by Richard Cash, an HSPH senior lecturer on international health and pioneer in oral rehydration therapy. Cash’s work in researching and introducing a simple saltwater-glucose solution that helps replenish the fluids lost during diarrheal illnesses is estimated to have saved the lives of 40 million to 50 million children worldwide since the early 1970s. He discussed water, sanitation, and health at the village level, pointing out that improved water quality can decrease waterborne diarrheal diseases such as cholera and hepatitis A, while increased water quantity can improve hygiene and sanitation.

The rest of the day’s speakers not only stressed the need for both interventions, but had suggestions on how to accomplish them.

The Massachusetts Institute of Technology’s Susan Murcott, for example, discussed systems for storing water at home safely and, more important, for filtering water in homes in low-cost, user-friendly ways, comparing the pluses and minuses of household chlorination, solar disinfection, particle-removal techniques, coagulation, and cloth, ceramic, biosand, and membrane filtration. “The biggest mistake we can make,” she said, “is to just drop technologies on people. There has to be an educational component and a monitoring process.” In one project she worked on, she added, because of successful education and monitoring, she and her colleagues were able to reduce diarrheal disease by 70 percent.

The comment “Here it is, my first visit to Harvard, and I’m here to talk to you about toilets” drew a laugh for Emory University associate professor of global health Christine Moe, but her topic, of course, is deadly serious to the millions of people around the world with inadequate sanitation facilities. Like Simmons English professor David Gullette, who leads students on service/learning courses in San Juan del Sur, Nicaragua, and talked about biosand filters, Moe spoke in detail about a particular technology — in her case, “eco-san,” or ecological sanitation, which turns a negative into a positive by converting human waste into fertilizer. “This is a relatively new concept that for awhile was considered lunatic fringe,” she said, “but there has been a real shift in thinking” in the face of the worsening global water shortage.

Daniele Lantagne, an environmental engineer currently working with the Centers for Disease Control and Prevention (CDC), spoke of point-of-use (POU), or home-based, technologies, such as cholorination products to treat drinking water and prevent the spread of microbes. POUs are necessary in many areas because a reliable infrastructure — which is the ultimate goal but requires political stability, a large investment of public dollars, conducive terrain, and population density — is lacking. POUs can be effective, but only if the product is good and there are adequate education and training programs, an easy-to-use and profitable distribution system, and, again, sustained monitoring.

International agencies, though key to taking water-improvement efforts large scale, are “constrained, half-blind actors operating in a complex process,” said Pete Kolsky, senior water and sanitation specialist at the World Bank. Still, they must support the creation of suitable enabling environments through capacity building, financing some of the risks of reform, and facilitation of shared experiences. They must also help to match global development funds to realistic demands — including the development of “bankable” projects and the underwriting of some of the risk of pilot programs — while lobbying for more resources.

Miriam Aschkenasy, a public health specialist with Oxfam, pointed out that one of the greatest challenges for obtaining clean water comes during times of crisis such as when civil war creates a refugee situation, for example, or, in the developed world, during a natural disaster like Hurricane Katrina. It is in part this realization that can help with compassion fatigue, which was the topic of Andrew Essex, chief executive officer of Droga5, an advertising and communications agency in New York City.

One campaign Essex outlined that helped to engage the public in this important effort raised thousands of dollars on March 21, 2007 — World Water Day — by inviting New York restaurant-goers to donate $1 for each glass of tap water they would otherwise enjoy for free. This project and others like it prove the point made by Richard Cash in encouraging students in the audience to take up water quality and quantity worldwide as areas of study. “The science behind these things and the implementation of them require a tremendous amount of creative work,” he said. “There are a lot of questions in research still open.”