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By Wendy Wolfson

February 10, 2003 | As you turn on the kitchen tap for a glass of water, realize how lucky you are. An estimated 1.1 billion people worldwide drink unsafe water, and 2.2 million children under the age of five die of water-related diarrheal diseases each year, according to the World Health Organization (WHO).

An ounce of prevention: An Aymara Indian woman in El Alto, Bolivia, uses sodium hypochlorite disinfectant to treat water in an improved storage vessel.
In the cities and shacks of the developing world, water systems are decrepit, inadequate, and contaminated. Even in towns where a water treatment facility exists, drinking water can be tainted by aging pipes, sewage, or bacteria flourishing in open buckets or spread by people's hands. Boiling to sterilize the water is not the solution; it consumes scarce and expensive wood and charcoal, and it takes time. Moreover, boiled water can often be recontaminated during storage.

For the past decade, epidemiologists Eric Mintz, Robert Quick, and Stephen Luby at the Centers for Disease Control and Prevention (CDC), together with USAID and other corporate partners, have been blending rudimentary technology with savvy marketing to make drinking water safe. Their approach is simple and dirt cheap — but it could save millions of lives.

One of the United Nations' development goals for the new millennium is to halve the number of people without safe water by 2015. But, as Quick points out, "If you reduce by half the proportion of people who have access, you still have the other half. How do you reach the hundreds of millions of people who don't have access to safe water?"

The CDC scientists are boldly challenging conventional wisdom about water treatment. Development money is usually spent on building large water treatment plants. But rather than wait decades for the piped water infrastructure to be built, the scientists ask, why not give people the ability to clean their own water now?

"We do support the effort to provide piped treated water everywhere," Quick says. "We are also realists. We are not going to see that in our lifetime . . . You can dig a well or a borehole with a nice pump, but you have to think all the way to the household. If the water is stored in a contaminated container or touched by a contaminated hand, it is contaminated."

The Safe Water System dates back to 1991, when CDC epidemiologists were invited by the Peruvian Ministry of Health to investigate a cholera epidemic that sickened a million people. Applying the kind of classical detective work originated by 18th-century London physician John Snow, who traced a cholera outbreak to a city water pump, the CDC team initiated a series of case-control studies to identify why people were getting sick.

"Time and time again, drinking water was the cause," Mintz says. "In cities, the municipal water wasn't safe. People were drawing water from shallow wells in rural areas." It turned out that cholera victims were more likely to store water in open containers. "Even if people did boil their water or had safe water, if the water supply was intermittent, they had to store it and were still at risk for cholera because of storage and handling. We figured out we could help people take dirty water and clean it. If you can implement the right measures, the outbreak usually ends."

The Technology 
The Safe Water System consists of a simple and cheap technology — a 20-liter lidded plastic water jug with a spigot and a narrow mouth to prevent contamination. A 0.5 percent sodium hypochlorite (the active ingredient in laundry bleach) solution is added to the water to disinfect it. The third component is behavioral modification.

The CDC scientists organized industrial design competitions at universities to develop an appropriate container. Next, they contracted with local plastics manufacturers to make containers that would be easy to fill but have a narrow opening so people wouldn't be able to stick hands or cups inside and contaminate the stored water. In Kenya, people didn't want to use plastic, so the scientists commissioned local potters who, drawing on a tradition dating back thousands of years, developed narrow-mouthed clay pots and added spigots.

Chlorination had a remarkable effect on morbidity and mortality when introduced at the beginning of the 20th century. Laundry bleach is relatively safe and has a long shelf life when stored in opaque containers. However, brands vary in strength and purity. The scientists wanted a uniform dose that could easily and safely be used to treat water, even by consumers who were illiterate. As people understandably balked at using off-the-shelf laundry bleach in their drinking water, the CDC team repackaged it as a separate product with its own brand identity and label.

After cleaning the water, the next step is to clarify it. People who have turbid water either drink it as is, try to clean it by letting it sit to settle the sediment, or filter it through a cloth. The CDC is helping to evaluate and test partner Procter & Gamble's PUR product — essentially, a water treatment plant in a packet. PUR not only chlorinates water but also is a flocculant, clearing the water by binding together the organic material and precipitating it as aggregated sediment. PUR is currently being test-marketed in the Philippines and Guatemala.

Proof of Concept 
Quick led the first successful tryout of the Safe Water System 10 years ago in El Alto, Bolivia, an urban slum 12,000 feet above La Paz. The residents drew on filthy water from shallow wells.

Quick's team set up a three-month study in which one group received new containers and bleach, a second received only containers, and a third group neither. The treated water in the storage containers with bleach was safe to drink, meeting WHO standards of no more than 1 particle of Escherichia coli bacteria, a marker for fecal contamination of water, per 100 ml.

Remodeled tradition: Women in a pottery collective in Nyanza Province, Kenya, display clay pots they made that have been modified for safe storage of water.
The following year, the scientists gave disinfectant and vessels to all groups and stocked a local store with disinfectant. Every family was still using the containers except one, which had its container stolen, and three-quarters of the families were still using the disinfectant. Those that weren't, it transpired, did not regularly visit the store, so a local church group began selling the disinfectant door to door.

Working with the Pan American Health Organization and Andean Rural Health Care, the CDC epidemiologists ran a second study in Montero, Bolivia, that reinforced these conclusions. At the end of the 10-month study, they documented an overall 45 percent reduction of diarrhea, even greater in infants less than one year old and in children between five and 14 years old. The effects were less pronounced in toddlers because they crawl and thus can easily pick up germs. At the study's conclusion, all participants received a Safe Water kit. Andean Rural Health Care produced the disinfectant and sold it at cost. When the scientists returned in 1994, they found that people were disinfecting produce as well. Even neighboring communities asked to buy it.

But when Mintz and colleagues presented their findings at scientific meetings, they received "lots of polite applause and encouragement," he says, ruefully, but nothing more. "People didn't jump for excitement. People said to us, 'Show that it works in the real world.'"

The CDC team resolved to get into business on a bigger scale. "A bunch of epidemiologists had to become entrepreneurs," Mintz recalls. "We wanted to demonstrate that this would work and would be self-sustaining."

Partnering Up 
In 1995, the CDC team turned to Population Services International (PSI), a social marketing company in Washington, D.C., to introduce Safe Water to Bolivia. PSI, experienced in distributing condoms in the developing world, uses focus groups, radio and TV advertising, and splashy events to change old customs.

Safety dance: Dancing water drops promote water disinfectant in a social marketing campaign in La Paz, Bolivia.
"Diarrhea is a hidden killer and the chief cause of child death," says Sharon Slater, program officer at PSI. "Safe Water goes behind the treatment to get at the cause. It is one of the least expensive child health interventions at 30 cents a bottle. It costs a penny a day to help a family of six. And we can get it out there fast."

PSI branded the Safe Water disinfectant "Claro," which in Spanish means both "clear" and "of course." The company staged a parade in La Paz, with people dressed up as water droplets. About 100,000 bottles sold in the first six months. The Safe Water kits are sold by local merchants and pharmacies at a small profit, along with other PSI-sponsored merchandise, such as iron supplements, and oral rehydration and clean delivery kits.

The CDC also collaborates with organizations such as CARE to introduce Safe Water. CARE identifies communities with substandard water quality and asks residents about their problems and priorities. Community members must support a new idea for it to be adopted.

One million to two million people now use Safe Water in 10 different countries, including Zambia, Madagascar, Kenya, Guatemala, Tanzania, and India. Rwanda is about to launch a Safe Water program, and the CDC may implement a system in Afghanistan. "It is just a small slice of pie," Mintz says. "We have a long way to go. But you go to these countries and see how intensely welcoming people are. Clean water is better than dirty water."

The scientists' next goal is even more ambitious. Ten million to 20 million people in Bangladesh are being slowly poisoned by drinking water that is naturally contaminated with arsenic. The arsenic also concentrates in rice, the local food staple. A number of arsenic reduction techniques are being developed. And Procter & Gamble is developing a flocculant agent to remove arsenic and heavy metals from water — a procedure that is being field tested in Bangladesh this winter.

The CDC scientists are looking for additional political support and funding for their innovative point-of-use approach. "We kept seeing ourselves as R&D experts," Mintz says. "We're not an implementing agency. We kept expecting that World Bank and USAID would step in and put some muscle behind it. That has been slow. The lesson learned: To really have an impact, you can't just have the solution. You have to see it through."

John Snow's spiritual heirs remain determined. Last August, Quick presented Safe Water at the U.N. World Summit on Sustainable Development in Johannesburg, South Africa. Plans are now being discussed to set up additional public-private partnerships. "I don't regard [Safe Water] as a silver bullet," Quick says, "but I know that it makes a difference in people's lives."* 

Wendy Wolfson writes about science and technology from Somerville, Mass. She can be reached at


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