Filtering Water with a Sari in Bangladesh

SariThe sari is a traditional form of dress worn by women in India, Bangladesh, Sri Lanka, and several other countries. While you may not be familiar with the name, the style is quite recognizable. Saris are usually long and flowing, multi-colored, and draped around a woman’s waist and over her shoulder. While often the marker of ethnicity, tradition, or style, women of Bangladesh rely on their saris for even more: water filtration.

The New York Times, has recently begun a new series of special reports: “Small Fixes, a special section on low-cost innovations that can save thousands of lives.” In a recent report, the Times notes that women in rural Bangladesh often use their saris to filter sweetened drinks, often to get rid of leaves, bugs, and various other debris.

While filtering a beverage of leisure offers many advantages, ten years ago researchers from Maryland realized that this simple technique could form the base of a much larger operation to relieve a very serious health risk. They discovered that “four thicknesses of laundered sari fabric, with its loosened, roughened cotton fibers, will strain out most of the microscopic plankton in water. In water contaminated by cholera, enough bacilli are attached to plankton for the quantity of cholera in filtered water to drop by more than 99 percent.”

Bangladeshi women from more than 27 local villages implemented the plan while retrieving drinking water from local rivers and canals. They “were taught to cover the urns they used for fetching water with an old sari folded in four. Over the next 18 months the rate of cholera in these villages dropped by about 50 percent, compared with other villages — about the same effect as that achieved by a much more expensive nylon water filter.”

Several years later researchers returned to the village to see if the plan had been enforced. Areas that utilized some form of water filtration noticed a drop in cholera outbreaks; however, women from several villages admitted to using only one strip of sari for filtrating water rather than the recommended four. The researchers learned that while there are simple solutions for complex problems, the solutions must be met with some form of continual reinforcement to have any lasting effect.