Biosand Filter Reduces Diarrheal Diseases

University of North Carolina researchers, lead by Mark Sobsey, are the first to scientifically document that filters made of concrete, gravel, and sand can significantly reduce the incidence of diarrheal diseases, the leading cause of death in many third world countries.

Sobsey and researchers in UNC's School of Public Health compared rates of diarrhea and the condition of drinking water in homes in two villages near Bonao, Dominican Republic. They monitored about 150 households without filters for four months, assessing the rate of illness. Then, about half the houses were given biosand filters - concrete containers that hold gravel and sand. All households were monitored for another six months. The team's initial analysis showed the filter reduced diarrheal disease among household members by an estimated 30 percent to 40 percent, including in highly vulnerable young children less than 5 years old. At the end of the study, filters were given to all participating homes.