Colwell has proposed ways people in the developing world can use inexpensive methods to filter water when water treatment facilities are not available. In one study spanning about 3 years, 65 villages in rural Bangladesh comprising 133,000 individuals, participated in an experiment in which they used folded sari cloth or nylon mesh filters placed over water pots to acquire safe drinking water from their local water ways. These inexpensive and readily available materials yielded a 48% reduction in cholera, when compared with the control: absence of any type of filter.